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Community and Q&A

Getting rid of old oil-fired boiler

ArseniyM | Posted in General Questions on
Hello everyone.  I’ll try to be as brief as I can possible be, so please, bear with me…
I’ve been looking for a replacement for my almost 20-year old oil-fired boiler since last year when I had to replace its DHW coil (pinhole that leaked into  the block and caused pressure-relief valve to release some water every
few minutes).  Not a big deal, BUT the plumber who changed the coil told me that my Burnham series 7 is well known in the industry as a “leaker” and that he was actually surprised the cast iron block made it this far.  Basically he
said something like: “it can last another 20 years, or it might not even last another 20 months”.  So last thing I want is to find myself in a situation where I’m forced to put another oil-fired boiler in my basement (or replace
my 60+ year-old oil tank).
I have natural gas pipeline running on my block (National Grid) and they can run it into the house for free.  Here, on Long Island, the bread and butter for all the HVAC guys is “oil-to-gas” conversions. By the way, I’m not sure why
they call it conversion.  Nothing is being converted.  Old equipment is *replaced* with one that uses different fuel type, that’s all.  So last spring I interviewed a bunch of HVAC contractors.  Quotes ranged between 11-13k,
which is outrageous.  Not one of them mentioned or offered to run a heat loss calc on the house or to even look at the type of radiation I have throughout the home.  Luckily last May, National Grid declared a moratorium that
suspended all new gas installations on Long Island claiming supply issues. The moratorium lasted until end of November.  This gave me enough time to study up on hydronics, do more research on equipment and also find/read a few VERY informative articles on this site that helped me a great deal (thanks  Dana!).
With all that being said, I guess I will be doing my own switch-over to natural gas once this heating season is over.  If I run into issues (piping wiring etc.), I’m hoping to get some answers on this website (that’s why I signed up).
Will post more information about the house, equipment that I tentatively chose, etc. soon.
Wish me luck,

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  1. Expert Member
    NICK KEENAN | | #1

    Have you looked at Dandelion Geothermal? Their bread and butter is replacing oil heat with geothermal. They concentrate on certain neighborhoods on Long Island and the Hudson Valley.

    1. ArseniyM | | #3

      Yes, I have. Seems very expensive and complicated for a modest 1800 sq ft home.

      1. Expert Member
        NICK KEENAN | | #21

        OK, good. I've only seen their PR, I'm not in their service area so they won't give me more details. Thanks.

  2. gusfhb | | #2

    Oh, how I dreamed of having natural gas

    Absolutely convert to gas, a condensing variable rate boiler will be cheaper than a decent oil boiler and cheaper to run.

    I don't have gas in the street, so I went with a Buderus GB125BE condensing oil boiler [10 years ago] and don't regret it.

    If however, you might be considering AC in the future, the current range of mini splits and ducted splits are very competitive energy wise, so you get the AC 'for free' if you will

    It is a big change so probably won't feel cost effective in the short term, and the change from FHW to FHA is not always an upgrade comfortwise.....

    1. ArseniyM | | #4

      Yes, was looking at Mitsubishi's low ambient (multi-zone) lineup. Very difficult to find a contractor who is not going to charge you an arm and a leg AND an eyeball.

  3. CollieGuy | | #5

    " 60+ year-old oil tank...". That just sent a chill down my spine.

    1. ArseniyM | | #6

      Yes, the house was built in 1957. We've been living there for just over 4 years now. I have every reason to believe that the tank is original. I'm watching it very closely.

      1. STEPHEN SHEEHY | | #14

        Watching your old tank closely won't help. I'd get rid of it. If it leaks, you're in a heap of expensive trouble, probably without coverage under your homeowners' insurance.

        1. ArseniyM | | #15

          Yep, agreed.

          1. Expert Member
            Peter Engle | | #26

            IN areas with oil heat, you can generally purchase oil tank insurance from your oil provider. If the tank is underground, I would definitely recommend it. IIRC, there is often a kick-in period, so you want the insurance in place before you consider replacing (or abandoning) the tank. I think 6 months is the norm in our area. There is also a replacement requirement: if the insurance pays to remove a tank and cleanup the area, you are required to install a new replacement tank. Usually a basement tank, or other inside tank. They can make you install the new tank, but they can't make you use any oil. Locally, the oil dealers will gladly buy the tank back from you at nearly the original cost. If the insurance does pay off for a cleanup, all of the restrictions will seem cheap.

  4. maheatpumpguy81 | | #7

    I'm having some difficulty with Mitsubishi's multizone systems at the moment. I'd encourage you to also price out a set of single zone systems. Based on my reading, personal experience, and talking with friends who also have heat pumps, the single zones seem more robust with higher efficiency.

    1. forcedexposure | | #76

      hello MAheatpumpguy81,

      What if you have one outdoor unit for each indoor head?
      Would the HP efficiency then be as good as having a single zone?

      thanks, Kris

  5. walta100 | | #8

    “By the way, I’m not sure why they call it conversion.”

    When homes stopped using coal for heat many of the coal furnaces were not replaced instead gas burners were fitted to the old appliances they were true conversions. It may be worth checking their maybe a kit to fit your old boiler. There were not so many lawyers and contractors were willing make something fit not so much today.

    “Basically he said something like: “it can last another 20 years, or it might not even last another 20 months”.”

    20 months you have no guarantee it will not leak in 20 minutes. As a matter of fact when anyone moving stuff around that is when you are most likely to open up a leak.

    “I will be doing my own switch-over to natural gas once this heating season is over. "

    Are you saying you will handle this project as a do it yourself project?
    You may find this forum more helpful


    1. ArseniyM | | #11

      I agree, if only the burner is replaced, then yes, it's a conversion. Otherwise it's a retrofit.

      Well, it's been some 11 months since the coil replacement. I sincerely hope that this thing can last a few more months. I will attempt to DIY this -- minus the gas connection and combustion analysis at the very end. So far the plan is to use a suitable mod-con boiler with an indirect. Still researching...

  6. tommay | | #9

    As Walter stated, you could install a gas conversion burner and run the boiler til it dies. This would give you time to decide on what you want to do. But gas conversion burners usually cost upward of $800, almost half of what a new gas boiler would cost, plus you have to pay for installation and removal of your oil tank, if you decide to have somebody else remove it if you can't do it yourself. That's amazing that the gas company will install a gas line for free. That used to be the norm but today then tend to charge you to run a new line, so if you can get it done for free, go for it, but you may have to install gas appliances in order for them to go forward.
    It's too bad your plumber couldn't repair the coil, since it's just a copper coil and the pinhole could have been soldered over, but obviously he is looking into selling you a new boiler. You should be able to look at the tag on the boiler to see how many BTU's output it has to give you an idea of what size new boiler you may need. If the old one kept up, a close match should suffice.

    1. ArseniyM | | #10

      The rule with National Grid is first 100 feet is free. Then it's some amount per additional foot -- it gets very expensive very quickly. You're right there is a suitable conversion gas burner for this particular boiler, but like you said, I don't think it's worth the effort since the block is pushing 20 years old. The new coil was just under $300, so I decided not to mess with the old one.
      In order for National Grid to sign off on the installation and set up a gas meter they must fire one piece of equipment to test. I'm planning to get a new grill for the back yard since I don't have one. The existing Burnham series 7 is grossly over-sized. Looking for a suitable mod-con to replace it with.

      1. tommay | | #12

        If you go forward with the gas line install, and since you are planning on doing it in the spring, you could purchase a gas hot water heater for them to fire. This would downsize the boiler so you can go smaller and having a separate gas HW heater will allow you to keep the boiler off 75 % of the year.

        1. ArseniyM | | #16

          Yes, that would be one solution. I will go either that way or set up an indirect. Still deciding/researching. Part of me wants to keep the boiler and water heater separate -- for redundancy. Which means I would need to install a stainless steel chimney liner which would cost about $1000 in my area. Also not sure about efficiency numbers if I were to go this way.

          1. Expert Member
            NICK KEENAN | | #18

            You can get a power-vented water heater that vents horizontally using PVC pipe.

          2. tommay | | #19

            If your chimney is in good shape, you may just have to have it cleaned. If you go with a conventional gas boiler you may not have to install a liner. If you choose a modcon, there is more moisture in the exhaust and it may require a liner. You can mix oil and gas in a chimney as long as the gas flue enters higher than the oil, if you decide to install a gas HW heater, so doing a cost comparison of the cost of a modcon and the price of adding a liner should be considered.

          3. Expert Member
            NICK KEENAN | | #20

            A condensing boiler has low-temperature exhaust, it's vented using PVC pipe pretty much anywhere -- roof, sidewall, rim joist.

          4. tommay | | #47

            Also if you choose to go forward with the gas install and install a gas HW heater, you can hook up the cold water input to the tankless so when the boiler is running in the winter it preheats the incoming water keeping the gas off. Just disconnect the aquastat to the tankless, if it has a separate one, so it doesn't cycle the boiler UN-necessarily.

  7. Deleted | | #13


  8. bfw577 | | #17

    Have you looked into solar there? Combined with heat pumps they would work awesome on Long Island. NY has the 2nd best solar incentives in the US with a 5-6 year payback. I am right across the sound on the CT shoreline and had solar panels put in 4 years ago. I caught the solar incentives here at their peak and they will be paid off next year. I have been heating my entire house with 2 12k cold climate mini splits almost entirely on my mostly free net metered electricity.

    There are alot of issues with natural gas in the tri-state area and New Engkand. The main issue is pipeline constraints and all the power plants running on it now. Many areas no longer allow new gas connections because they probably know new gas pipelines arent happening anytime soon.

    There is also high monthly connection charges, ususally around $20-30 a month even if you dont use any gas.

    Then there is gas leaks and the fact you have combustion and venting going on with a potential for co2 poisoning. I feel a mini split is far safer considering there is no combustion involved and the fact the main part is outside.

    1. Expert Member
      BILL WICHERS | | #22

      I’d be much more concerned with carbon monoxide poisoning than CO2. Your body can detect high concentrations of CO2 and will make you want to exhale and leave (it’s not a pleasant experience). Gas leaks are pretty rare too.

      The biggest issue in New England is the capacity constraints in the transmission system. This is the cause of gas shortages and high prices in that region. There have been recent capacity issues that resulted in suspension of gas service to some areas (as in they were shut off for several days), so if you’re in one of the SEVERELY constrained areas, that would be a good reason to consider options other than natural gas.


  9. jj1 | | #23

    Hi ArseniyM: I recently installed a heat pump HW heater (Rheem Performance Platinum), 3.55 Energy Factor, in my Southampton, Long Island home. $650 after giving effect to PSEG-LI's $650 rebate. It works great. I also installed a PV rooftop system; the federal 26% tax credit plus NY State's 25% tax credit should allow you to generate electricity at much lower LCOE cost than the local utility's rates, if your location is suitable for PV. If yes, then Long Island's relatively moderate winter temperature lows are a good fit with a mini split heating and cooling system.

  10. Expert Member
    NICK KEENAN | | #24

    As a sanity check I would try to calculate the heat loss. There are online Manual J calculators, although with an old building it's hard to know what the actual construction is. The other approach is to take the actual fuel bill for a year. You have to estimate your hot water usage and your boiler's efficiency, netting them out gives you actual BTU's consumed for the year. Find heating degree-days for your location for that year, and you get BTU's per degree-day. Divide by 24 to get BTU's per degree-hour. Find the design temperature for your area and subtract from indoor temperature to get temperature delta, multiply that by BTU/degree-hour to get design heat loss.

    With that you can size your heat source. You can also assess your radiators. Condensing boilers are more efficient with lower water temperatures so if you have enough radiation to warm the house with lower temperatures that's good. If your radiators pencil out with water temperatures of 120F or lower you could even consider an air-to-water heat pump, although that might be outside your adventurousness zone. As a DYI installation air-to-water can be simple, no gas hookup and the refrigerant is all in the box, the only inputs are water.

  11. gusfhb | | #25

    An oil boiler this old has lived its life, let it die in peace.

    Simply changing fuel type is a waste of money
    It will be cheaper short term[maybe] but much, much more expensive in the long term

    1. tommay | | #27

      Keith, these older boilers can last forever if properly used and maintained by occasional flushing and water conditions are fine. Since he just replaced the tankless coil he should just ride it out and he may get another 20 years out of it just as his plumber said. It's always nice to have a secondary type of fuel available if one wants to add other types of appliances such as his gas grill, so if and when the boiler goes, he has options, especially if he can get a gas line installed for free today, because it will probably cost him tomorrow.

      1. Expert Member
        Dana Dorsett | | #28

        >" Since he just replaced the tankless coil he should just ride it out and he may get another 20 years out of it just as his plumber said. "

        In 20 years using #2 oil or natural gas for space heating might even become contraband in NY if that state follows the trend of states targeting "statewide net zero greenhouse gases by 2050". At some point the most cost effective way to lower greenhouse gas emissions will be to require that people stop setting fossils on fire.

        While it's rarely cost-effective to scrap a heating system, sometimes it's the right thing to do with other aspects factored in. Even the smallest cast iron boilers are ridiculously oversized for the heat loads of a <2000' house on L.I., and those big enough to deliver reasonable domestic hot water performance are ludicrously oversized for the average load. (And I've yet to find one that also air conditions.)

        1. tommay | | #29

          Obviously you don't under stand the electric agenda, it can easily be turned off anytime they want. Just look at what PG & E during the supposed wild fires in CA. I watched a movie recently and they had to shut down the city's power grid and they said they could use wild fires as an excuse.....coincidence? Alternative fuels can be made from organic materials, something they don't want us to know which would do away with "fossil" fuels....Remember what edison said, it's no good if we can't put a meter on it.....
          As far as greenhouse gases, I guess we should deforest the entire planet to solve that problem, or should we?

          1. Expert Member
            Dana Dorsett | | #30

            Yep, it's just a big conspiracy by evil utility companies and their shareholders/board members.

            How would switching to the gas grid get rid of the metering problem anyway? Getting rid of the 60 year oil tank is part of the reason for switching.

            Buy a wood stove.

            Then buy a PV system capable of islanding.

            The "alternative fuels" that will work in an oil or gas fired boilers have limited production capacity constraints using the available methods & materials that are financially viable. The "they" that think it's a good idea (as opposed to the "...they.." who "...don't want us to know..." ) have been working on it for decades, but it's still way cheaper to keep poking holes in the ground.

          2. Expert Member
            BILL WICHERS | | #31

            Natural gas can, and sometimes is, shut off the same as electricity. This actually happened last year in part of Rhode Island if I remember correctly (it was in the northeast). Oil deliveries can be halted, and that happened too during the hurricane in that area several years back. Oil is shipped by pipeline to local terminals in cities, similarly to natural gas.

            If you really want to avoid “the man” for energy, you need to go live out in the woods somewhere, using wood for heat and maybe a fully offgrid solar or microhydro system. Any other option requires you to have some level of dependency on larger energy infrastructure. It takes A LOT of effort and expense to be even somewhat resilient in terms of self sufficiency energy wise, and that’s something I get into with my contract work. Rarely does anyone plan for more than a week of fuel. The biggest system I was ever involved in was 60 days or so, and it was a BIG budget project and not for a private entity.

            There is no big conspiracy here. The companies that provide the energy services need to get paid. They have operating expenses and payroll to make. The California utilities also have to content with a pretty twisted set of government regulations such that they are financially liable for fires that start around their infrastructure, even if it’s not their fault at all. There is a LOT of finger pointing out there. I grew up as a kid with parents in the utility industry and there are a lot of stories from the utility side about stupid government bureaucrats causing all kinds of problems that the utilities would get blamed for. Be careful who you believe when you listen to crazy sounding ideas on either side here.

            The scale is just not there for biofuels to replace conventional fuels. There are also other tradeoffs, like more ethanol has the side effect of reduced corn for foodstocks, with resulting higher prices. Nothing comes for free, unfortunately.


        2. ArseniyM | | #33

          Never expected so much input on this. It became difficult to respond to everyone very quickly :)

          Thanks Dana for commenting. I read your articles and did the "napkin" math. Based on my findings -- I SHOULD be able to condense most of the heating
          season. Still, I could use a second opinion just for sanity check.

          Here it goes. The house is a typical Long Island split level -- has 2 zones (will post pictures of the house as well as the existing equipment over the weekend). 3/4" copper finned tube baseboards all over. First zone is the family room (behind the garage) and a half-bath ~ approximately 25 feet of finned tube. The other zone is the rest of the house ~ 85 feet of finned tube. The number one candidate that I'm currently looking at is a Navien NHB-80 plus an indirect (HTP or Laars 40-45 gallon). NHB-80 goes all the way down to 8000 btu/hr which is quite remarkable.

          Last oil delivery happened on Jan 14th (143.5 gallons), the prior one was on Dec 16th. Assuming that the tank was filled to the same level both times means that I went through 143.5 gallons in 29 days (December has 31 days). Can't tell how much of this went towards DHW, but I don't think it matters too much.

          1. Expert Member
            Dana Dorsett | | #39

            The system may be prone to cycling a bit excessively at condensing temps on the 25 foot zone. At 95% efficiency the NHB-80 can only modulate down to about 7500 BTU/hr out, divided by 25 feet is ~300 BTU/hr per foot. With typical fin tube that balances at an average water temp of about 140F. The entering water temp at the boiler needs to be well under 130F to get much condensing efficiency out of it.

            If it's possible to add another 12- 15' of fin tube (or an equivalent amount of other radiation to those rooms in a way that won't upset, or possibly correct room to room temperature balance on that zone) it'll be a lot easier to tweak the system into "modulating condensing nirvana".

            The higher pumping head of the water tube heat exchanger of the NHB pretty much demands that it be configured primary/secondary. Fire tube heat exchanger types like the Lochinvar KHB/WHB-085 or or NKB080, or HTP's UFT-80W can almost always be pumped direct, and have some water volume thermal mass in the boiler to help quell short-cycling issues when one or more zones doesn't have quite enough heat emittance at low temp to emit the minimum fire output of the boiler.

            With only 110' of baseboard total on the system there isn't even enough radiation to be able to deliver more than ~55-60,000 BTU/hr of boiler output into the house, even at 180F-out.

      2. gusfhb | | #35

        Tom, over and over you give suggestions that will not save the OP money, even on a modest time scale

        When oil was less than a buck a gallon, fine, whatever.

        When it can approach 4 bucks a gallon, the difference between a 70 percent oil boiler and a 90 percent gas will be stunning.

        24 hours a day, that uninsulated oil boiler drafts air past its heated core and out the chimney. When it cools down, even in summer, it occasionally belches to life and heats that core up again so that hot water is available from the instant coil.

        broad numbers, looks like he is going to burn about 800 gallons of heating oil in a year.
        cost about 1760 bucks, right now[oil is cheap this year I guess]
        Updating from a 70 percent to 90 percent[yes 90 percent oil boilers are available] drops to 1370

        gas is 75 percent cost per BTU compared to oil

        Changing to 90 percent gas: about 1000 bucks a year

        And, gas boilers require, in general, less maintenance

        just in big roundy numbers, 700 bucks a year less

        Mini splits seem comparable to efficient gas, electricity in the NE is high, so running costs.....

        Honest to god, what kind of favor are you trying to do this guy?

        Not to mention green, blowing that much waste up the chimney every year...

        And, in anticipation, there are chances that the oil boiler is worse than I think, burner efficiency is not boiler efficiency. With outdoor reset, variable firing rate, cold start and direct vent, the waste factor of a modern boiler is tiny compared to the old monster. IIRC the Europeans rate boilers over 100 percent to allow comparison of these type of effects

        1. ArseniyM | | #36

          Keith, you're right on the money with most of your estimates. I am going through about 900 gallons of #2 heating oil each year (both heating and DHW). I have a habit of keeping all the delivery receipts, this is our 5th winter in the house, and it's remarkable how consistent it's been season after season. House is kept at 70 degrees. I don't do any setbacks unless we're away for more than a couple of days. On Long Island prices are slowly creeping up towards the $4 / gallon mark.
          $3600 is way too much to pay for heating and hot water. I know it should be less than half of that. Before Sandy, there was no gas pipeline on my block, but after people were out of power for about two weeks, several of them got together and went to National Grid and that's when the pipeline was extended to my block from a neighboring street. Those people changed over to gas and now they have stand-by generators. Those generators are waiting for another Sandy that might never come.

          1. gusfhb | | #38

            Were I you I would check out the options and kind of the relative pricing on products that seem interesting. I would check in with, pretty good variety of folks there and you might even get a good referral to do the work. Guys who know how not to oversize boilers, have experience with newer equipment.

        2. Expert Member
          BILL WICHERS | | #37

          It’s probably also worth mentioning that natural gas is generally more price stable than oil is, so you’ll have a more predictable heating cost in the future. Oil seems to be more prone to price spikes than natural gas.

          Personally, I’d very seriously look at the natural gas option if you have it available and aren’t in one of the super constrained natural gas areas.


          1. Deleted | | #57


        3. tommay | | #46

          Keith, there are other ways of lowering your oil consumption to save yourself money without changing over to a "more efficient" boiler. I recently changed out an old oil burner that used 3 gph to a new burner and installed a nozzle that uses 2 gph and their cost savings payed for the new burner in one month and they continue to save each month while still providing the necessary heat. It could even be lowered more than that. Cutting down on usage or turning thermostats down or off is more effective and cost nothing. Cycling a boiler from cold start to maximum heat takes more energy as opposed to leaving a thermostat set at one temperature keeping the boiler warm thus requiring less input, which allows you to lower your fuel consumption. Maintaining a constant temperature in your home works in the same way. Putting on a sweatshirt and getting up and doing something as well as maximizing the amount of sunshine coming into your house may allow you to turn your system off completely.
          Simple solar hot water systems, black pipe in the sun, can rid yourself of hot water bills 75% of the year, glycol systems can do it for you year round and contribute to heating in the winter. But unfortunately, this is hardly spoke of and it seems weird especially on this site which is called "Green" building advisor.

          1. gusfhb | | #51

            Tom, you are easily 40 years behind the times

            For instance, my oil boiler runs a .75 GPH nozzle and supplies H+HW for a 2800 sq ft home, 69 degrees no setbacks, average usage 580 gallons per year, last 10 years. My house is north of, probably larger than, and has twice the glass of the OP's

            320 gallons less? I think not with an old pin type boiler

            One can buy a mod con boiler and lower temps or shut of zones or take other methods of saving energy as you mention, saving even more money/fuel

            Those who wish to wear a sweater may do so while paying less to heat than with an antique inefficient boiler.

          2. tommay | | #58

            Kieth, this was on a big, old, large commercial boiler, not a small residential boiler, but the same principles apply. I haven't turned my boiler on in three years since my neighbor cut down trees that blocked all the sunlight and my electric meter shows 2800 Kwh for those same three years.. And I've been in the plumbing and heating business for nearly 40 years and the solar business and mechanical engineer for 20. What's your experience?

  12. tommay | | #32

    Once again Bill, you are right. There is no one fits all solution. We have to be diverse in all our energy needs. Energy is everywhere and without it, we wouldn't exist. Incorporating what is available in our local environment, eliminating transmission is best for all. The sun shines all around the world and is our primary source of all energies along with motion. We cannot let all these energy barons control what nature gives us for free. Realize all of the energy infrastructure comes from the earth of which nobody owns or has the right to claim as theirs.

  13. jenniferz5 | | #34

    May I piggyback on this great discussion with a related question? Dana, you suggested that the OP buy a woodstove. I have a Hearthstone Clydesdale woodburning insert in the main room of my 1400 sq ft, one-level ranch, that keeps the entire home (except for the two furthest rooms on the W-facing side of the house) perfectly comfortable on the coldest days (Zone 5a, CT). The Man J does not take into account that we use this as our (very effective) primary heat source. Going by your informative articles and advice, I am going all electric, but a heat pump (Mits. P-series hyper heat) would be perfect without supplemental heat, but too much with what we already have. I wonder if a Minotair with the 12 kw (17000 btu) duct heater would be enough (with the fireplace and electric strips, if needed)? (Our Man J says that we need 33000 btu of heat.) Can you help me understand if I am on the right track?

    Updated to add: my woodburning insert has a "Maximum Heat Output of 60,000 btu/h."

    1. Expert Member
      Dana Dorsett | | #45

      >"Dana, you suggested that the OP buy a woodstove."

      Actually that was intended as a bit of sarcasm toward Tom's take on the utility companies, not that I really object to the use of wood for heat .

      >". I have a Hearthstone Clydesdale woodburning insert in the main room of my 1400 sq ft, one-level ranch, that keeps the entire home (except for the two furthest rooms on the W-facing side of the house) perfectly comfortable on the coldest days (Zone 5a, CT). The Man J does not take into account that we use this as our (very effective) primary heat source. "

      Manual-J is completely agnostic of fuel & equipment. Manual-J only calculates how much heat/cool is needed, completely setting aside the sources and methods of delivering that heat as an exercise for others. So of course it doesn't take into account the wood burner.

      If you are using a FUEL USE load calculation you MUST take all fuels into account, including the wood burner. There are big error bars around the BTUs delivered with wood burners, since the efficiency varies as does the BTU content of the wood itself, but it can't be ignored.

      >"I am going all electric, but a heat pump (Mits. P-series hyper heat) would be perfect without supplemental heat, but too much with what we already have. I wonder if a Minotair with the 12 kw (17000 btu) duct heater would be enough (with the fireplace and electric strips, if needed)? (Our Man J says that we need 33000 btu of heat.) Can you help me understand if I am on the right track?"

      Codes generally require a heating system capable of heating all normally-occupied rooms to 68F at the 99% outside design temp, controlled a thermostat that measures the air temp (not the temp of the heater, not the temp of the floor, etc. ) Even if the wood-burner is your primary source of heat, the automatic system is still required to be capable of delivering design condition heat. It's legitimate to use strip-heat on a ducted heat pump to meet that requirement, as long as it engages automatically with the controls.

      BTW: 12 kw x 3412 BTU/kw-hr= 40,944 BTU/hr not 17,000 BTU/hr.

      Which model Minotair are you looking at? Most of their products' heat pumps have fairly tiny output in heating mode, heating output that is only a fraction of it's rated cooling rating at design temperatures that matter. Cold climate heat pumps are usually capable of more heating BTU/hr at +17F than cooling BTU/hr @95F. So if it becomes the primary heating source it's going to be running the strip heat (a lot) with a design heat load of 33,000 BTU/hr.

      A 2 ton ducted Fujitsu AOU/ARU24RGLX out more than 24K with just the heat pump, and IIRC has the control hooks to engage (but not drive) strip heat, and probably isn't ludicrously oversized for pairing with a wood burner, capable of throttling back to under 6000 BTU/hr at your 99% outside design temp:!/product/25350

      Or perhaps the Carrier/Midea 38MAQB24R--3 / 40MBDQ24---3 two ton ducted heat pump:!/product/26450

      1. jenniferz5 | | #50

        Thank you, Dana! That clarifies quite a bit for me.

        My very competent HVAC guy suggests a Mitsubishi P-Series ducted heat pump for just the reasons you gave, and, while I trust him, it is a huge investment for something we may not need. After a month (Jan) of ONLY electric space heat, our electric usage was 2495 kWh (biggest bill EVER, obviously). Last January, using mostly our wood stove, it was 860 kWh. Yes, a huge jump, but remember that I am using four space heaters to keep our home toasty at 67-degrees (which is where I normally set the oil furnace thermostat).

        We should be able to start up the wood stove again this week, which will raise the indoor temps and lower my electric usage tremendously. Is spending $30k+ on the heat pump going to be worth it in the long run, especially if I am happy with the wood stove as the main heat source and the Minotair to ventilate and give it a boost (along with electric strips in those two West-facing rooms)? (Maybe the answer is yes, which is why I am asking.)

        To answer your question about the Minotair, I'm not sure which unit it is, but my HVAC guy says, "the big one." It gives 250 cfm of heat and has a 17kw duct heater.

        1. bfw577 | | #52

          I am in CT as well and using electric space heaters for heat is insanely expensive. Its about 3 times more expensive than oil or propane. On a per btu basis its the equivalent of paying $6.75 for heating oil. CT has the highest electric rates in the lower 48 according to the eia. So you are using a wood stove and plug in electric heaters? What do you do if nobody is there?

          I have solar panels with net metering and have been heating my entire 1800 sqft split level with 2 12k btu mini splits. I don't actually purchase the power but if I did it would have cost me around $80-100 a month the last 2 months. A good cold climate mini split will deliver 4 times the heat per kilowatt compared to electric resistance heat. 2 18k single zone units would save you alot of money.

          I also have a wood insert that I still use occasionally. Ever since I put my mini splits in I barely burn anymore. Too much work involved when I can just leave them running and it maintains a perfect temperature 24/7 using very little solar generated electricity.

          1. jenniferz5 | | #68

            Excellent point re: what to do when we want to leave the house for more than a few hours. For a small home, every replacement option is so costly. I don't want to make a mistake. Thanks for your advice and help.

  14. Expert Member
    Dana Dorsett | | #40

    Zephyr writes:

    >"Natural gas can, and sometimes is, shut off the same as electricity. This actually happened last year in part of Rhode Island if I remember correctly (it was in the northeast)."

    Were you thinking of the Lawrence MA gas distribution grid mis-management fiasco/disaster, when the gas had to be turned off for a few months?

    Sticking with an oil boiler doesn't allow disconnection from the electricity grid or "the man". It still needs the electric grid, and the number of refiners & distributors of #2 oil in any given region is a very small number, even if the number of retailers can be large. To an extent greater than natural gas (and WAY greater than with electricity) #2 oil pricing is subject to the high price volatility of international markets. Getting rid of the higher local air pollution of oil burners vs. natural gas is good, but it goes the other direction if displacing oil heat with a wood other biomass burner. When retail #2 oil was bumping on a $5/gallon not too many years ago as crude was trading north of #100/bbl pellet stove sales in the northeast soared.

    1. Expert Member
      BILL WICHERS | | #41

      >"Were you thinking of the Lawrence MA gas distribution grid mis-management fiasco/disaster, when the gas had to be turned off for a few months?"

      It might have been that. I remember it was an issue with National Grid, a "low pressure due to transmission shortages" issue where they shut off some thousands of people for a few days. I was thinking Rhode Island but may be mistaken. I'm pretty sure it was last winter.

      I agree with you about the oil still keeps you dependent on "the man". I've heard the "electric grid so they can turn you off" argument before, but people seem to forget that natural gas can be turned off just about as easily, and that HAS happened on occasion.

      If self sufficiency is the goal, I really only see the options being wood heat and a big, wooded lot to supply you with wood (this means BIG usually, at least 10 acres and probably more, especially if you want to use deadwood), non-grid tied solar or microhydro for electricity. A really nice combo would be some kind of wood stove or wood boiler and minisplits running on your solar or microhydro power the rest of the time. There really aren't any other options that are in any way practical for regular people. As soon as you have to order in any kind of fuel, you're back dependent on someone else again.


      1. Expert Member
        Dana Dorsett | | #42

        >"There really aren't any other options that are in any way practical for regular people. As soon as you have to order in any kind of fuel, you're back dependent on someone else again."

        Exactly (which is why my eyes reflexively rolled back with Tom's comment about what "Obviously you don't under stand..." about the "...the electric agenda.").

        1. tommay | | #44

          Well, humans existed for thousands of years without electricity, and a good part of the world's populations still did they and how do they survive?

          1. Expert Member
            Dana Dorsett | | #49

            >"...humans existed for thousands of years without electricity, and a good part of the world's populations still did they and how do they survive?"

            Probably with oversized cast iron boilers. :-)

            Most people currently living without electricity would still prefer to have it. YMMV.

            A significant part of Narendra Modi's initial campaign & popularity was based on the promise of bringing electricity to the villages with a HUGE push toward PV solar (of all scales and utility/distribution models.)

          2. Expert Member
            BILL WICHERS | | #53

            Tom, there are two main kinds of people out there trying to greenify things:
            1- people who think we should all go back to ancient ways, use almost nothing, and just deal with a primitive existence.
            2- people who try to use modern materials and methods to get the most benefit from the least resources

            Most people on this site probably fall into group 2. Most people would NOT want to go back to how things were in ancient times, even if they think they are in group 1. My wife grew up in one of the old soviet satellite states that had a major earthquake and they were without power for several years (for several reasons). It was a fairly modern civilization suddenly forced to deal with no modern energy services. She can tell you how very NOT fun that was. Most people can not imagine something like that, for that long of a time period. GBA’s own Martin wrote an article about the natural gas disruption that caused that mess and did a pretty accurate job describing it if you’re curious.

            The simple reality is that modern civilization can NOT exist without modern energy infrastructure. There is no way around this. What we can do is to try to use that energy as efficiently as possible.

            If you want to see what it takes to really do some serious off gridding, read this guys site:
            I admire his efforts here. It’s a very extensive microhydro setup and he documents everything he did to build it all.


          3. Expert Member
            Dana Dorsett | | #55

            Bill: If you click the video link in response #48 you'll find there is a third (if not main) category of people out there trying to greenify things:

            3- people who believe the laws of thermodynamics can be violated, and that "the government" or "big oil" some other "they" motivated by incumbent profits & greed are keeping the world from infinite amounts of "free" energy by withholding or suppressing the technology that makes it possible.

            (Don't bother watching the whole video- its 18 minutes 49 seconds of your life that you'll never get back.)

          4. tommay | | #59

            Bill, I have installed solar pv, solar hot/pasteurized water and micro hydro systems for ancient civilizations as you call them, in remote villages 10000 ft up in the Andes mts of peru. Up until then they survived and still survive without power and their lifestyle is more enjoyable, less stressful, healthier and more peaceful. The systems we installed were mainly for communication for emergency situations which would take days for those in the cities below to respond and saved multiple lives by getting the response they needed, as well as battery charging stations so they can have some lighting for personal use. Otherwise people would have to make a days travel down and a day back. But the point is, there are still plenty of areas that survive without the creature comforts that we enjoy.

      2. tommay | | #56

        Dana, I expected this kind of response from you. Obviously, you missed the entire point of the video.

        1. Expert Member
          Dana Dorsett | | #60


          ... not the target audience. (My mind must be clouded by the physics & math education..)

          1. Expert Member
            Akos | | #61

            The fault valuing logic and science over truthiness.

          2. Expert Member
            MALCOLM TAYLOR | | #62

            Oh you and your Book Learning!

        2. Deleted | | #64


  15. bfw577 | | #43

    Close to Long Island Con Edison has a moratorium on new gas lines as there is no more pipeline capacity. They are actually paying to convert people to non-gas heating such as heat pumps as opposed to building more gas lines.

    To address the supply-demand imbalance, and help existing customers reduce the amount of gas they use, we are pursuing non-pipeline solutions that will reduce our reliance on fossil fuels through innovative, clean-energy technologies. On February 7, the New York State Public Service Commission approved our portfolio of innovative solutions aimed at lowering the demand for natural gas through energy efficiency and demand response programs, along with programs to help customers with alternative technologies that reduce natural gas usage, such as heat pumps

  16. tommay | | #48

    Everybody should watch this young lady's video. You may learn something

    1. MattJF | | #63

      Ahh, so the ideal heating system on Long Island uses water as a fuel.

      What is the the sub 5f performance of these systems? Does is it drop off like some heat pumps?

      1. AndrisSkulte | | #79

        Matt - If you're talking about geothermal, then outside air temperature has a very minimal effect on performance once you go below 12 feet if you do a deep loop. Lots more here:

  17. CollieGuy | | #54

    As an aside, our two ductless mini-splits satisfy just about all of our home's space heating needs. However, last week, with temperatures dipping as low as -17°C and with winds gusting at 90 km/hr., our oil-fired boiler got pressed back into service for the first time this winter (I'm not keen on burning fossil fuels, but the house was getting damn uncomfortable and it was time to give in).

    Our fuel oil consumption over the two and a half days that we ran the system came to 16.6 litres or 4.4 US gallons (52-year old, 2,900 sq. foot Cape Cod). The enclosed PDF provides a break-out of each burner cycle.

    In short, our mini-splits have more than earned their keep, but in terms of pure physical comfort, nothing matches hydronic heating.

    1. _Stephen_ | | #65

      "nothing matches hydronic heating"

      Have you ever lived in a super insulated house? With enough insulation, everything is just the same temperature, and the type of heating doesn't really matter so long as it doesn't overshoot.

      1. CollieGuy | | #66

        I don't live in a super-insulated home, but the walls are (nominally) R22, the attic R60, and the windows and doors Pella Architect Series low-e/argon. That said, once temperatures fall below -15°C and the winds start to howl, these outer surfaces radiate cold and, consequently, comfort takes a hit.

        As to whether this is a meaningful guide or not I'll leave to you, but according to Efficiency Nova Scotia, our home is 29 per cent more energy efficient than the top twenty of one hundred comparable homes within our neighbourhood.

      2. gusfhb | | #67

        When you blow air on someone, it makes them feel cooler

        Pretty much always

        I grew up with infloor radiant, and have always loved it.

        Next best is big radiators, which always give you a place to be warm if you want.
        My last house was actually half radiant floor half forced air[Monitor kerosene] with very similar levels of insulation, radiant is more comfortable

        If you actually use so little heat that you cannot feel the air move.....but then you drop to one minisplit and need to move air

        When you are saving money/the planet, the warm feeling inside will make you feel better.....

  18. ArseniyM | | #69

    Attaching pics of the equipment and the house. Again ~ 110 feet of finned tube baseboards total. Two zones. You can see the 3/4" exiting one of the circulators -- that's the family room behind the garage. This room has 22 feet total going lengthwise and width-wise plus 3 feet in the half bathroom. So 110 - 25 = 85 feet for the rest of the house (zone number 2). That zone starts off as 1". Then about 20 feet later, while still in the basement it splits into two 3/4" loops, one goes around the upstairs, and the other goes around the first floor in opposite directions. They join back together in the basement to become 1" again and back to the boiler. Note that the expansion tank and the boiler feed are on the return side -- don't know why. Also there's no air separator -- just the little air vent. Thoughts? Criticism?

    1. ArseniyM | | #70

      Turns out I can only attach 5 images. So I'm responding to myself with the rest.

    2. tommay | | #71

      Yeah that's quite a mess. Looks like a home owner install. The boiler itself looks okay. Those zones that are split, you could install a ball valve to control the flow better or better yet get the whole thing re-piped correctly so you have one continuous loop for each zone or re-pipe the zones into one and eliminate the other pump. Like you said, no air scoop, xpansion tank not where it should be (boiler output), no proper mixing valve on the tankless (just a ball valve), no pig tail on the oil line, looks like the air intakes on the burner are completely closed (may have to do a combustion test or adjust the flame/airflow yourself so it burns completely and hot), it's not properly valved off to isolate and purge the individual zones, air vent looks old and crusty and probably doesn't work, looks like a spring check instead of a backflow preventer on the boiler feed, check the flow checks after the pumps to make sure they are working correctly by adjusting the screw cap on top, all the way up is all the way open to flush, then screw it back down and of course drain, flush and purge the entire system......You should have showed these pictures earlier. Small nightmare but it should be able to be rectified easy enough.
      Fix these few thing and the boiler may operate better by getting the correct flow and burning correctly.

      1. Expert Member
        Akos | | #72

        It actually looks pretty good, maybe because I've seen some pretty terrible ones.

        There are the issues that Tom pointed out. The location of the feed and expension tank doesn't matter much since those old cast iron boilers are low enough pressure drop. If you are changing to a modcon, than moving them would be a good idea. I would definitely change out the check valve to a proper backflow valve.

        If you are doing major work on it, changing to a single ECM deltaP circulator and 2 zone valves might be worth it. You don't have enough baseboards to need two separate pumps, plus this would use around 1/4 the electricity of your current setup which is a around a 3 year payback in my area of expensive electricity.

    3. Expert Member
      NICK KEENAN | | #73

      Glad to see that it's not an in-ground oil tank. I have a feeling that in a few years using fuel oil to heat houses will seem as unbelievable as using whale oil for light or mummies to fire steam boilers (as the British are alleged to have done in Egypt).

      Finned tube is normally 550 BTU/hr/ft, so with 110 feet that's 60K BTU worth of radiation -- at 180F. No point in getting a bigger boiler than that, you can't use more than your radiators put out. Do the existing radiators keep you warm?

      This would be a good time to do some insulation and weatherizing, maybe a blower-door test. The payback period for improvements is much better if they mean you can buy less expensive equipment.

    4. Expert Member
      NICK KEENAN | | #74

      I would put a zone valve and thermostat on each of the loops. Since they split off in the basement the plumbing is easy, running the wire for the thermostat is probably the hardest part.

      1. ArseniyM | | #78

        Well, upstairs are 3 bedrooms, a couple of small bathrooms, and a little hallway. Not sure where to put the thermostat. This way the 85 foot zone would become 2 zones of approximately 40 feet of baseboards upstairs and 45 downstairs.

  19. gusfhb | | #75

    Well, not over old, not over huge, water feed a little wonky. While the air separator/ex tank 'belongs' at the pump input, the old boiler was probably plumbed similarly. Unless it gives you some sort of problems, I would not be tempted to mess with somewhat minor issues such as that.
    I have a similar split zone setup and it causes me no problems I am aware of.
    When you do replace it they are going to cut it all out with a sawzall anyway, so don't spend too much time thinking about it.

    If you had a water bed to fill, that hot water system is awesome.....probably the worst of that system efficiency wise. Keeps the boiler hot 24/7/365 in case you need hot water. Back when I was young and broke me and the roomies would shut the boiler off at night and turn it on first thing in the morning for showers, then shut it off again.

    At the end of the day, this boiler is what it is, 20 years old, bottom third efficiency wise when it was made, but it is by no means on its last legs, for better or worse.
    Upside is you have time to do research and figure out your best path forward.
    My feeling is a mod/con with an externally fired water heater is going to maximize savings, but there are a bunch of ways to go.
    If up front cost is an issue, getting rid of that HW system in favor of say a heat pump water heater might be an interim measure. One could change the boiler to cold start, and even put a smaller nozzle in it, but one needs to check with the manufacturer, some boilers dislike being cold started, and you need an oil guy who doesn't mind fooling around a little bit[and you don't mind paying him to]
    I am running my house heat and hot water at 90k BTU net output, and wish I had the guts at the time to go with the 76K

  20. ArseniyM | | #77

    All of the above is true. With both circulators running I can take a really loooong shower when it's 10*F outside. The house would still stay at 70*F. BUT, like I said before -- I'm going through about 900 gallons of oil each year. With prices slowly edging up to the $4 mark -- it sucks to realize that my neighbors that changed (I refuse to say "converted") to gas paying less than half of what I pay (houses on my block are identical). However at 13-15k for a change-over, the break-even point is about 7 years. A coworker of mine just went through with that (also on Long Island). The contractor installed a Rinnai combi. Not sure which model, but doesn't matter. They set the thing to run at 170*F. They never even mentioned (or installed) an outdoor reset. The house is just under 2000 sq ft micro-zoned into 3 zones. I know that even with all 3 zones calling for heat, the existing radiation will NOT be able to emit the full output of the thing running even at the minimal input. Will be interesting to find out just how SHORT are the cycles. He already bragged about how much floor space he saved in the basement. Ugh... decisions, decisions...

    1. AndrisSkulte | | #80

      ArseniyM - We're not far from you in central CT. I have an unknown vintage oil fired hydronic baseboard heat in our 1700 sq ft 1960's 2 story cape that we just "replaced" with 2.5 tons of Mitsubishi Hyperheat mini split (two 9k's downstairs and two 6k's upstairs). This winter, my wife ran the oil furnace twice when I forgot to turn up the fan on the mini splits so the hallway would be warm in the morning. Once we broke our habit of setting them back overnight, the house feels great. I'd have no problems ripping out our now spare oil furnace, but we'll hang onto it for now...

      CT Natural Gas also finally ran a gas line up our street last year, so we could have connected for "free", but at the cost of a $10k gas heater replacement. I've been happy with the choice we made, and also not having gas connection charges throughout the summer when only hot water is needed. Our hot water is a separate oil fired 80 gallon tank, which I'll replace with a hybrid eventually. Might even plumb up a solar evacuated tube system for the spring/summer/fall since we have tall oaks to the south that partially shade the roof (preventing a big solar panel system) .

      After rambling so long, consider all electric, especially if you have the option to Net Meter solar down the road.

    2. gusfhb | | #81

      Again it is necessary to get wise counsel.

      as mentioned, is full of professionals who know modern heating systems

      I might start here:

      because I like Buderus[now Bosch], but check reviews etc
      An indirect is another 1000 bucks, depends on size, and you will need another pump for that circuit and its plumbing.
      Doing the labor is twice parts means your 10k estimate is not bad, but maybe in the summer you might get some competitive quotes

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