Ground Source Heat Pumps 'Require No Maintenance?'

D107

In the northeast heat pumps are getting a lot of PR; in our area in Westchester, NY ground source heat pumps ––currently for forced hot air/AC systems––are being promoted with incentives. I am always skeptical of claims of no maintenance requirements whether for mod-cons or GSHPs. There's the obvious annual filter change, and making sure sheets of ice don't fall or 'grow' on the outside compressor in winter, but what kind maintenance should consumers be aware of before they put their money down on these. (Of course there's other issues like adequate heat and hot water coverage, what % of the time the electric element will have to run, etc.)

EBEBRATT-Ed

Everything needs maintenance because anything mechanical can and will break. That being said.

Most water source heat pumps I have seen are indoor packaged units.

The ground water loop is usually glycol so the glycol and water quality needs to be checked yearly. If it is a well that's a whole different story.

So you have a glycol (water) pump

A refrigeration system..not much maintenance unless you get a leak

Air filters
Blower, blower motor and bearings

Cleaning of air side coil

cleaning refrig-water heat exchanger. Probably not necessary with glycol in a closed loop

Expansion tank, relief valve, backflow preventer and glycol make-up

I agree that if they get the maintenance they need they should run a long time without a major problem if sized and installed correctly.

I have not installed many but 1 job I did I was very impressed with the quality of the "Water Furnace" equipment

D107

@EBEBRATT-Ed if this is for a forced hot air system, then I'll assume there is no expansion tank/relief valve/backflow preventer ?

D107

Others on this site have also talked about getting the ground loops done right in the first place--sizing the pipes correctly and put at the right height. And also making sure that for a particular location there is no affect on any aquifers--there are restrictions in our town on certain locations for that very reason.

EBEBRATT-Ed

@D107
It's a ground source heat pump so it has water. You need an expansion tank and a relief valve as a minimum if it is a closed loop.

SuperTech

I have worked on several ground source heat pumps in your area. The units aren't as maintenance sensitive as oil fired equipment but it would be foolish not to have the stuff professionally cleaned and inspected annually. Besides the reasons above I can add that you have wear and tear items like contactors and capacitors like all heat pumps. While most are package units I have seen several split systems with all the pumps and compressors in a mechanical room piped to various air handlers. Refrigerant leaks are common. There's wide variety of quality of work being done with that equipment. Some of the companies installing those units shouldn't be.

solradman

We do GSHP for both forced air and radiant and we check them at least once every year if hydronic heating and twice a year if forced air heating and cooling. With either type we look for and do the obvious and we test of the ground loop water side performance. (GPM x delta t (temperature drop) x 490). This tells you the heat of extraction. If it is close to manufactures stated numbers than the system is running as it should. If lower than its time to do some more troubleshooting. Check the fluid level and test the antifreeze and good to go. Also if using a non pressurized loop system no need for expansion tanks or reliefs. Same test for pressurized systems.

pecmsg

Only needs maintenance after it breaks!

TAG

I had a cabin in PA with a lake loop system .... the cabin was a couple years old when I purchased ,,,only owned for 5 years. Never touched it -- it did have a pressure tank and gauges that we monitored.

The guy who built the little development had a bigger house with the same system (water furnace) .. he had some issues because the unit was a little undersized and ran all the time.

It's really no more complex vs an air to air heat pump. It was in a remote location making propane deliveries difficult and expensive. Being a lake system it was cheaper to install .... that said today the air to air would be the way to go.

mikeg2015

Our experience has been they are maintenance free other than air filter changes. Like most modern “maintenance free” items, it simply means disposable. When just out of warranty they often develop coil leaks and It’s cheaper to replace and get a utility rebate again, then repair. We push inverter air source and minisplits instead.

For what you spend on a geo system, you could ultra insulate a home and just use a minisplit even in a cold climate with similar operating costs.

ethicalpaul

EBEBRATT-Ed said:

@D107
It's a ground source heat pump so it has water. You need an expansion tank and a relief valve as a minimum if it is a closed loop.

I had an atmospheric (non-pressurized) loop pump running a closed loop with glycol. It was very nice, didn't require any expansion tank, relief valve, purging station or anything.

https://iwae.com/shop/geo-pulse-non-pressurized-flow-center-single-pump-ha12100.html

In the 5 years I lived there, I just replaced the filters, it was really nice. Installed it myself on a Saturday including pulling the old oil furnace that was there. I had the well drilled by a pro of course. He sunk the loop pipes and did the grout as part of the job. Terminated them into my basement foundation for me.

That ground source heat pump AC sure worked nice in the summer.

G Averill_2

Closed loop fluid quality is one thing overlooked in these systems. We stress to check the fluid pH and glycol percentage with each annual service check. I only get involved in fluid or flow issues, but see a lot of problems like this one:

hot_rod

G Averill_2 said:

Closed loop fluid quality is one thing overlooked in these systems. We stress to check the fluid pH and glycol percentage with each annual service check. I only get involved in fluid or flow issues, but see a lot of problems like this one:

What is that a picture of? May I use it in my fluid quality trainings?

G Averill_2

Bob, I forwarded this picture plus another to your e-mail, along with system descriptions.

hot_rod

> @G Averill_2 said:
> Bob, I forwarded this picture plus another to your e-mail, along with system descriptions.
Got it, thanks