Electric heating and cooling

[Thor.266]

Trying to determine potential cause for failure of the Reversing Valve for an electric Ameristar heating and cooling system—100% electric home. Outside heat pump compressor is 3 ton; which seems to fall inline with 1 ton per 500 sq ft., for a 1,500 sq ft 3-year old well insulated house in Washington—about 8 miles south of the Canadian border. HVAC company diagnosed with failed switch valve and needs new heat pump compressor for $10k—but parts under warranty—or an entirely new 2-ton system; including new air handler in the garage, for $20k. We were told system is oversized for the quality of the house build. Even if the heat pump is slightly oversized could that cause the failure of the switch valve? Or did the switch valve failure cause the heat pump to have issues?

 

[Breplum]

A load calculation is called for to determine proper sizing of equipment. Rule of thumb or 'off the cuff' won't do.
I would think that the original installation would have required load calcs. Check with your county inspection records for load calc record.
Get multiple (at least two more) service/replacement bids.
I don't think $10k is reasonable to replace the compressor when the part itself is covered. Unfortunately Ameristar is not a premier brand known for longevity.

 

[Sponsor]

 

[Fitter30]

Switch valve is the reversing valve. They want 10k to replace the valve and compressor and the parts are covered. Call another dealer if you have the paperwork for the warranty. Assume the compressor went bad the reversing valve is the first piece off the compressor. It has some small tubing ,orifices and the valve has a slide piece that travels in a tube back and forth. The valve gets replaced with the compressor in case some debris came out of the compressor at the time it failed that would stop the valve from functioning. Second what Breplum post states. Might want to call your electric company ask about a energy audit with a blower door test to see how.tight the house is.

 

[Thor.266]

Switch valve is the reversing valve. They want 10k to replace the valve and compressor and the parts are covered. Call another dealer if you have the paperwork for the warranty. Assume the compressor went bad the reversing valve is the first piece off the compressor. It has some small tubing ,orifices and the valve has a slide piece that travels in a tube back and forth. The valve gets replaced with the compressor in case some debris came out of the compressor at the time it failed that would stop the valve from functioning. Second what Breplum post states. Might want to call your electric company ask about an energy audit with a blower door test to see how.tight the house is.

It’s a 3 year old well insulated 1,500 sq ft house—walls are 6 inch studs and dual pane storm windows and door seals…so without a test I can tell you the house is tight—no leaks. Other homes same size have 2 ton outside units while ours is a 3 ton and houses just 100 sq ft smaller have split units. This house was built during late 2021 COVID supply chain issue and finished May 2022. I’m thinking the 3 ton unit was installed because a 2 ton was not available???

 

[Thor.266]

A load calculation is called for to determine proper sizing of equipment. Rule of thumb or 'off the cuff' won't do.
I would think that the original installation would have required load calcs. Check with your county inspection records for load calc record.
Get multiple (at least two more) service/replacement bids.
I don't think $10k is reasonable to replace the compressor when the part itself is covered. Unfortunately Ameristar is not a premier brand known for longevity.

The estimate for a new system; comparing the fix price to a new install cost, determined the house is well insulated and came in with needing a 2 ton outdoor unit.

 

[Fitter30]

Probably oversized. Cooling air is the easy part the harder part is relative humidity. If a unit sized for the space it should run long enough to put RH below 50% and you want rh below 50% for mold.