I would like to permanently remove three upright cast iron radiators (there is one in each of our three second-floor bedrooms). These three radiators are all currently connected to a whole-house hydronic system that serves both the first and second floor all as one zone. (We don’t need these radiators anymore since we’ve recently had mini-splits installed). My question is: do I need to have a plumber or hvac person remove these, or could any handyman or carpenter do the work? And do I need to have work done to any other parts of the hydronic system (pumps, piping, etc)? Thanks.
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I would have a mechanical contractor familiar with hydronic heating systems do this work. You may need to do some balancing work when you're done, which isn't something a typical handyman is going to be familar with doing.
The answer may also depend on where you are. Most jurisdictions allow either licensed plumbers or the homeowners to do repairs and modifications to their plumbing, but some preclude other contractors from doing the work.
You want someone that is familiar with hydronics. A lot of plumbers won't be up for the job, so you'll have to do a bit of searching. Definitely not a handyman job.
Make sure they cap the lines bellow the level of your subfloor so the holes in your flooring can eventually be patched.
Overall you are looking at least one, most likely at two days without heat.
OK, thanks guys. That's what I needed to know. Hopefully removing these radiators is not more complicated/expensive than installing the mini-splits that replaced them. The reason I want to move the cast iron radiators is because I want to put electric baseboards in their place, right where they are in the bedrooms. Our new mini-splits do most of the heavy lifting of heating the house, but the bedrooms could each use a little supplemental heat just to take the edge off. The problem with using the hydronic system to do this is that in order to get heat to those cast irons up in the second-floor bedrooms, I need to turn the boiler on for at least 45 minutes and heat the entire house in the process. Seems like a tremendous waste of energy, whatever the source of power that boils the water in the boiler. I've toyed with the idea of adding a separate hydronic zone for the second floor bedrooms and just leaving the cast irons there as the supplemental heat source, but I imagine that would be expensive, and it still wouldn't allow for individual temperature control in each of the bedrooms when some of them are not in use (for example, one is a mostly day time office, while the other two are bedrooms for sleeping at night with different members of the family going to bed at different times). So it still seems like the best way forward is just resistance baseboards in the bedrooms, each with its own thermostat....
Definitely a plumber. Is the whole system one zone? Those radiators may be installed in series or more likely in a monoflo configuration. If in series you will have to connect the inlet and outlet somehow to keep the rest of the system workable. If monoflo you may be able to just disconnect and cap the lines going to them in the basement. They should have valves going to them at the radiator which you can turn off if you don't want to use them or to regulate them. If they are taking to long to heat you may have air in the lines or in the radiators themselves. Each radiator needs to be bled individually especially if it is monoflo. Once working correctly, you may find that they work well. Not sure why you would want to remove them, might be something to keep just in case, especially cost wise if you plan on putting in electric. Adding a second zone may be costly as well. Baseboards can also be adapted or added to the lines going to the radiators if you really want to get rid of them or get more heat.
Make sure you get an older plumber, younger ones may not be familiar with monoflo systems and will try to talk you into a whole new system of which they are familiar.
Thanks, Tom. Before I put in the two Fujitsu wall-units on our first floor, my first choice would have been to actually keep the hydronic system and its cast iron radiators and just install an air to water heat pump. But I couldn't find an installer locally who would do that. So now that I have the mini-splits, which do 95% of the heating in the house, the second-floor bedrooms only really need a little bit of supplemental heat to raise the room temperature 5F or so at times. So the question now is what is the best way to do that. The whole system is one zone, yes (well, there is a first floor addition that has its own zone - but most of the first floor and all of the second floor is on the same zone). Interesting point about air in the lines - I'll look into that. The main reason to take them out is to have a more efficient and local source of minor, supplemental heat in the bedrooms - the mini-splits do most of the heating in these bedrooms indirectly, it's just a question of raising the temp 5F or so when the doors are sometimes closed. One reason I'm leaning toward replacing the cast irons with electric resistance baseboards is because it seems really inefficient to boil water in the basement, send it through the radiators on the first floor, then send it to the radiators on the second floor every time one second floor bedroom needs a little bit of supplemental heat. But it would certainly make my life simpler to be wrong about that - I suppose I could just have a plumber install an electric boiler and leave all the radiators alone. But another reason I think it makes sense to rip out the cast iron radiators is because the radiators have been there for decades, maybe even close to a hundred years (house built in 1925), and this has created two problems: 1.) they've created some air sealing problems by damaging the walls they're up against - separating the base molding from the wall, warping and thinning and cracking the plaster itself, etc. - but they're so close to the wall that I don't know how to fix this other than by totally removing them, and 2.) their shape and the number of fins they have and their close proximity to the wall has caused them to accumulate decades of dust and gunk in a way that is kind of impossible to clean well - I think they would just have to be removed to really clean the space up between them and the walls.
I'm not sure what you mean when you say firing the boiler would be inefficient -- 100% of the heat from the fuel would go into the house. In most places electricity is the most expensive "fuel" for heating so running the boiler is a lot cheaper than running resistance heat.
Maybe I'm missing something, but what I'm getting is you need some sort of supplemental heat because the minisplits don't keep up on the coldest days. So you want to keep the radiators on the first floor but not the second?
Depending on how they're plumbed, it could be about the same amount of money to switch them to a separate zone as to remove them. I think that would work better for you. If you're opening the whole system anyway it's not a big job to remove an individual radiator and send it out to be sandblasted and painted (although it can be a chore getting them down the stairs if they're heavy. But someone got it up the stairs so it's doable.) Fix the trim while it's gone and you'll be as good as new.
The system can be drained down and the radiators should be able to be easily disconnected to do repairs behind, then cleaned, painted and reconnected, refilled and bled. A lot less work and money than replacing. I like old cast iron radiators whereby if the are used correctly they tend to radiate and stay warm over time limiting cycling of the boiler.
Realize in a monoflo system, all the radiators will get or should get warm at the same time so it's not so much you are heating downstairs and then heating the upstairs. If upstairs isn't heating as fast, there's air in the radiators and the water is not making it's way up there.
+1 for using the existing hydronic system as supplemental heat and not electric resistance baseboads. DC is entirely correct about operating costs here.
I would look into zoning those bedrooms. Depending on how the system is currently plumbed, the cost to split the bedrooms off into their own zone may be less than you'd think. If the cost to put in that extra zone is less than the cost to remove the old radiators and install electric resistance baseboards, then you definetely come out ahead with the zoned hydronic system.
Keep in mind that those electric resistance baseboards might be surprisingly expensive to install. I was just in a box store this morning and happened to look at the prices of $$ coppper $$ wire $$$! AGH!!!