Quick Heat Pump Help Please

If it's 6 degrees outside, the heat pump won't be contributing much, if any, heat to the system, though it might still run. Feel the suction line with your hand. If it feels hot, then the heat pump is actually still heating (I'll bet that it just feels lukewarm). If it runs for a while before satisfying the thermostat, it'll go through a defrost cycle where the outdoor unit fan stops spinning and the compressor keeps running. After a minute or two, you'll hear a whooshing sound, the fan will kick back on, and a large billow of steam will rise up and out of the unit - that's normal, don't freak out. After you open the furnace door, you might have to remove a cover to see the heat coil connections and count the heat coils; they're generally 5kw each except for Rheem & Ruud, which are, I believe, 7kw each. If you turn the system to the emergency setting and crank up the thermostat, the coils should all come on in sequence. Use a clamp-on amp meter to make sure that they're all working. In the upper midwest I suspect that those coils get a heavy workout and it wouldn't be unusual to find that one or more are broken. Also just look at the wiring. I often find toasted wires and connections. You really can't test the heat pumpness of the heat pump when it's that cold out. I'd explain that and tell them to have the whole system serviced when clement weather returns. Also tell them that the single best thing that they can do for their heat pump is to keep the filter clean, keep the outdoor coil clean, and don't let dogs pee on it. Jim Katen

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