AMana/Gree PTAC Question

vtfarmer

Hi y'all. I would like to get the PTAC in my sunroom to use the heat pump mode more often instead of the resistance heat. It's one of the Chinese Gree manufactured but Amana branded units, model PBH093G35CC. There is nothing in the manual about locking out the electric heat, though there are instructions to do the opposite (lock out the heat pump). This wouldn't be such a big deal except that the electric heat is used any time the indoor air is more than a degree less than the setpoint and the resistance heat also cuts in at other times (when the outdoor temp is below some limit that seems too high).

They do sell an adapter which appears to permit the use of a standard wall thermostat, part PBTCK01. Does anyone on here have experience with this? My hope is if I put a standard heat pump thermostat on the unit using this adapter, that the thermostat override the logic in the unit and force the heat pump and electric heat to function as commanded by the wall 'stat. These units do not have automatic defrost so I would have to be mindful of that, but the other three heat pumps on the house very seldom need to defrost here so I am not super worried about that.

My fear is that the unit will receive the heat pump command (R to G for indoor fan, R to O for reversing valve, and R to Y for the compressor to run) and the control board will override this to force the electric heat on most of the time as it currently does. Can someone here verify that it will work that way, or not?

vtfarmer

Update: I bought the PBTCK01 and hooked it up to a generic Residio wall thermostat and had the same issue: even when the well stat calls for heat pump mode, the heat strips will run until the room about reaches the set point then the heat pump will run after that. The heat pump will also not run if it's below about 40 outside. Major bummer!

So, two ice cube relays and two larger 30A DIN rail mounted relays for the compressor and heat strips, and some very tedious wiring later (they don't give you much room in there), the PTAC is controlled by the wall stat exactly the same way a conventional ducted unit would be. Anyone need the circuit boars for an Amana PTAC?

pedmec

Honeywell makes a hp thermostat that you can adjust the aux heat cut in settings to a lower setting. this will prevent the heaters from energizing but still having the defrost function. I don't have the model # available. your best bet is to call the manufacturer and explain your situation. they also might have a thermostat to function the way you want it.

John Mills_5

Most PTHPs shut down in the 30s (coil temp in the 20s) as they have no defrost capability. That's in the unit not the stat.