Repair or Replace Heat-Pump Water Heater
I have a 7 year old GE heat pump water heater. 50 gallons. It probably can be repaired and GE even supplied a kit to boost the fan capacity. The unit is installed in the basement, which is separated by R30 insulation from the house. I do plan to add a short duct regardless of the unit I choose to move the exhaust air further from the unit. By moving the cold air output a few feet I think I can improve efficiency, but that is a side issue. The output would go into a “cold room” where I can store potatoes in the winter.
The main question is whether it it is now time to replace the unit instead of trying to make it work a few more years. Here are the numbers I am working with.
Current Unit:
GE Geospring, operating in electric mode January to March, heat pump the rest of the year, compressor may be failing, purchased via MassSave program. Estimated COP for the unit is about 2.0 as the basement temperature ranges from around 52 degrees to 63 degrees during the month when the heat pump is used. This April I tried heat pump mode but it made me revert to electric resistance (I got an error code). I don’t know a tech who is experienced fixing these units.
Potential New Unit:
Probably a Rheem or AO Smith. Would go with 50 or 60 gallons. Would like to be able to run as a heat pump all year. I wonder if a COP of 3.0 or higher would be achieved all year round. I know that my situation in the summer when the basement is relatively warm and humid will be idea. In the winter the basement has some moisture but no mold and runs from 45 to 50 degrees. Cost of these units start at $1100 to $1200 and I don’t think I can get a rebate anymore.
Thanks for your help.
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Replies
Rich,
Be sure to check out an earlier question by clicking on the "view more" button and going back two pages. The question is about compact HPWH. I have an extended comment on that question that may be helpful in your decision making.
I am deducing that you are in Massachusetts, which means your electric costs are likely high by most standards. If you are able to get outside air most of the year that is above 45F then you might find sticking with HPWH worth the upgrade. The parameters you set out might mean the the Geospring is sprung or you have asked it to work outside the programming that attempts to ensure you have adequate recovery and draw down for showers.
Many units are programmed to default to resistive heating mode when either air temperature falls to low or the incoming water lowers the tank temperature to a particular set point. For many reasons, 80 gallon units will behave more efficiently than smaller ones. Determining what the program modes are actually doing re water and air temps is not discussed in the Rheem Manual I have downloaded. Probably a function of TMI and TL-DR.
The fact that you have plans to chill your potatoes is curious. Where is the air going after it gets shot into the cold room? The one I grew up with was isolated to maintain constant cool and relied on ground temperature to moderate. I am not sure that directing the cold air in will help if you create a static back pressure on the ducting.
After you read the other question, I can maybe offer some further guidance. Is the entire basement isolated from the heated living space by R30 in the floor?
I installed the fan upgrade on my 2nd gen Geospring back in 2013 a few months after I bought it. I was getting an error as well. Called GE tech support and they sent the kit. The replacement fan was much more powerful than its original fan. I suspect the early fans were underpowered. It's been running 7 years nonstop in heat pump only mode since then with no issues. The fan wasnt that difficult to install. I would install it and see it goes away rather than junking it.
If you can't handle the repair there is a nationwide GE appliance repair division that still works on them I believe. I think they are called A E services.
It is also possible you have a 1st gen unit that was manufactured in China and they had refrigerant leak issues. I think those units were blue. The 2n and 3rd generation units were made in the USA and were much more reliable. Those units are red. If you have the first generation I would probably replace it.
As Roger mentioned it seems based on a recent post newer units will still turn on the electric elements in the software. The Geospring in heat pump only mode does not. I had an electrical monitor on mine for a few years and I never saw the elements come on. In fact it will actually run even with the elements disconnected as I ran some tests.
So i got a couple days of warm weather and the basement is back to 55 degrees or higher. Looks like the heat pump is operating again, though with the filter errors. So i will attempt the repair... Or even better locate someone who has done it before. I'm 28 miles north of Boston. Yes i have 2nd gen.
As for redirecting the air i think i have a good setup. No it wont alter the temperature of the cold room much... It's a big area containing all sorts of service pipes. The water heater is now in a big closet with louver window and no door and still, it is dropping the temps at the air intake.
Honestly it is a poor design of any heat pump to put the intake and exhaust 2 feet apart. It's not going to give you the efficiency you need.
My redirection will be a duct that travels just 18 inches.
The geospring is really easy to take a apart. I take mine apart every 2 years to clean the coils and inspect the anode rod. The fan was really easy to change. I put a link for the service manual on how to do it below. There are also YouTube videos on how to take it apart as well.
It could also be your coil is really dirty and restricting air flow. Home Depot has the coil cleaner you spray on. I would do that while you are in there if you decide to try the repair.
http://waterheatertimer.org/pdf/GE-heat-pump-service-manual-2012.pdf
Thanks for the tip. I may try it. So if it needs an anode rod is there a compatible part at plumbing supply stores? I don't want to have to take it apart twice after waiting a week for a ge specific anode rod.
Then again, i guess i won't need to use electric resistance again until November.
hi BFW577 -- I took apart my geospring today and I wouldn't say it is that easy to change out the fan. I have to remove a fan control cable from the circuit board and it seems to not allow me to reach to the bottom of the connector and properly take it off.
Also it instructs me to pull back the cap on the relay using a flat blade screwdriver but I guess you have to have exactly the correct size screwdriver to get into the release slot. I put in 2 different screwdrivers and it won't come off, I am afraid I will break something.
I am going to take a break and maybe it will be easier in a few hours to get this done. I am sure I can replace the fan, it is just tough getting the two cables for it connected!
Regarding the coil cleaner thanks for the tip. You mean the thin metal part that looks like the back of an A/C unit? It appears to have rusted a bit but is not too dirty.
So I was able to remove the fan control cable (pulled up the insulation and it revealed a metal tab that could be pulled back with a razor blade). And I was able to remove the cap on the relay (after a trip to Home Depot to get just the right size screwdriver). It was still not easy to get things to move, after all this is the first time the water heater was opened in 7 years.
One tip for others attempting the fan repair: I ended up not even replacing the existing "gray wire", the one that was so difficult to remove from the control board. Instead I cut the existing gray wire and attached it to the new fan's gray wire with a wire nut, to avoid having to unpack the sleeves containing bundles of wires.
I didn't need to do that for the brown wire, because routing that wire to the relay is not that difficult (though you do have to be careful removing the small zip tie that holds the old brown wire in place at the connection to the relay).
But the water heater is back together and it appears to be working. I will try running a few diagnostics to see the input and output temperatures now that this repair has been done. First, I should let the unit dry out, as as I sprayed lots of coil cleaner and water on the top of the unit.