The coil in our Hayward HP21003T heat pump installed around 2009 and heating our 14,000 gal lap pool since we bought the house in 2015 turned into a block of ice a few days ago. The display showed "defrost" mode. I shut down the heat pump, let it thaw out, and started it back up. The compressor motor immediately started up but the fan didn't start after the power up delay. After running a few minutes the coils started freezing up instead of producing condensate since the fan wasn't running and the humidity is very high where we live
A friend/HVAC Tech came over with his gauges to see if the R-22 refrigerant was low. Fortunately it was fully charged. We checked voltages and the contactor was getting 240 volts and the relay energizing coil was getting 24 volts so all was good at these points. The fan motor showed resistance so the fan motor windings were good. We manually engaged the fan contactor and the fan started up just fine. We pulled the cover off the compressor contactor and discovered it was closed and providing immediate power to the compressor. The contact points appeared to be "welded" together.
The two contactors in this unit appear to be the same as the contactors in most every AC condenser on the market. I've ordered 3 of these https://www.amazon.com/gp/product/B07VBPB8YT/. This particular part costs about $5 more than the usual replacements but has premium higher silver content contacts and the energizing coil is enclosed. The order for 3 totaled $58 and I will now have a spare for the next failure. From what I’ve read, contactors have an expected life of 5-10 years. The two in the heat pump are about 16 years old so I hope replacing both of them solves the issue. I'll replace both every 5 or so years going forward.
Just sharing this info in case it helps others. Obviously don't do this if you don't have HVAC pressure gauges and a volt-ohm meter and you aren't comfortable working around 240 volt AC circuits. But if you are, you can save yourself a LOT of money. Replacing the Heat Pump is around $4K ! Given ours is 13 years old that time may come if the refrigerant coils develop a leak.
A friend/HVAC Tech came over with his gauges to see if the R-22 refrigerant was low. Fortunately it was fully charged. We checked voltages and the contactor was getting 240 volts and the relay energizing coil was getting 24 volts so all was good at these points. The fan motor showed resistance so the fan motor windings were good. We manually engaged the fan contactor and the fan started up just fine. We pulled the cover off the compressor contactor and discovered it was closed and providing immediate power to the compressor. The contact points appeared to be "welded" together.
The two contactors in this unit appear to be the same as the contactors in most every AC condenser on the market. I've ordered 3 of these https://www.amazon.com/gp/product/B07VBPB8YT/. This particular part costs about $5 more than the usual replacements but has premium higher silver content contacts and the energizing coil is enclosed. The order for 3 totaled $58 and I will now have a spare for the next failure. From what I’ve read, contactors have an expected life of 5-10 years. The two in the heat pump are about 16 years old so I hope replacing both of them solves the issue. I'll replace both every 5 or so years going forward.
Just sharing this info in case it helps others. Obviously don't do this if you don't have HVAC pressure gauges and a volt-ohm meter and you aren't comfortable working around 240 volt AC circuits. But if you are, you can save yourself a LOT of money. Replacing the Heat Pump is around $4K ! Given ours is 13 years old that time may come if the refrigerant coils develop a leak.
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