Mini PTAC Heat Pump Mode

[PhilBarnett]

Hi! I'm new here - I hope I posted correctly.

I've had my new mini PTAC for just over a month and lately it seems like when I have it on heat mode it's running resistance heat. I'm in NW Washington - pretty mild. I run it when it's above 40°. Is there any way to force it to use the heat pump mode?

The unit is an Amana PBH113G35CC. The resistance heat uses 3,000-3,500 watts... Bleah. There was a note with the unit that lets the operator select resistance only or both and I have it on both. When I first used it for heat, it was blowing air out the back and water was draining out the back (normal heat pump activity).

I had a Kenmore heat pump for a long time that would use the heat pump almost constantly. Again, is there a setting on this thing to force heat pump usage?

Thanks for any input!
Phil

Update. I just remembered that perhaps I should treat it like computers and computer accessories - I unplugged it, plugged it back in and when I turned it back on I could hear immediately that the heat pump activated. It's running like it should. Is this a normal thing to have to do? Thanks!

[joemach]

If I recall Amana PTAC units go into electric heat around 45-50 degrees. Or at least they used to.

As far as your other question, you should be able to call Amana on that one.

[BaldLoonie]

Might be a bit colder. Usually around freezing since they don't have a defrost control. Most of those suckers turn on the electric if the temp is a couple degrees below setpoint. So if you leave it sent at one temp in 40+ weather, probably wouldn't need electric strips.

[PhilBarnett]

Thank you joemach! I tried them first and all I got was "Are you a consumer or a pro?". When I said consumer they said they don't help consumers and I should ask a pro...

[PhilBarnett]

Thanks BaldLoonie! I'll set it higher and see if that helps. My last one would try so hard - below 43 or so it'd pump out the heat until it froze over. I got used to it. Plus, it last 29 years!

[kdean1]

Last I knew, it has nothing to do with ambient temperature. If the indoor temperature is within 2* of the setting it uses the heat pump. If the demand is more than 2* it switches to strip heat. That means if the heat pump cannot maintain temperature and the room temperature continues to fall it will switch to strips.

[PhilBarnett]

Last I knew, it has nothing to do with ambient temperature. If the indoor temperature is within 2* of the setting it uses the heat pump. If the demand is more than 2* it switches to strip heat. That means if the heat pump cannot maintain temperature and the room temperature continues to fall it will switch to strips.

Thank you Dean - I've been playing with it and I think your (you're ) right. If I start it up at a lower temperature it seems to use the heat pump. What a pain. I'll continue to try to find a way to make it run on heat pump until I tell it to stop.

[kdean1]

Thank you Dean - I've been playing with it and I think your (you're ) right. If I start it up at a lower temperature it seems to use the heat pump. What a pain. I'll continue to try to find a way to make it run on heat pump until I tell it to stop.

There is no sensor for outdoor temperature. The design is to maintain a temperature indoors. If the heat pump fails to keep up it turns off the compressor and uses the strips. The circuit won’t suuport both operating at the same time.

[DeltaT]

Most of the customers I've had that had your problem is because they turned the PTAC off during the day or while they were away. That is when the HP goes into backup heat because it's being asked to heat the room quickly. Heat pumps are good for maintaining indoor temperatures at their designed specifications but they are not that good at heating up a cold room if left off for a while. Let it run 24/7 & during mild to slightly cold weather you will see it stays in the heat pump mode most likely. Really cold weather then most likely it will not produce enough heat in HP so it will switch to electric heat.

[PhilBarnett]

Thank you DeltaT! That's exactly the way I use it. With my old unit, I was using a woodstove below 40° and the HP above. My old unit just ran heat pump until it got cold outside. With your input maybe I should heat the place up with wood and then turn on the HP when it gets warm.
I'm not looking forward to my next power bill...

[BaldLoonie]

The manual says there is an outdoor thermistor so the system knows whether to run the compressor as 1st stage or go straight to electric. Again, usually its around 30° when the comp is locked out.

[PhilBarnett]

That's exactly what I want it to do. It's 39° outside right now - I've had the woodstove going and it's 74° inside. I just turned on the unit - set to 75° - and it went straight to electric.