Heat Pump + Aux Heat Problem - Can You Help?

[whitedavidp]

Hello. I have a relatively new house (2.5 years) that has an American Standard Heat Pump (2a6b3018-060a1000a). It also has some form of American Standard aux heater (bayhtr???) in the air handler. This is controlled by a Panasonic TH8000 thermostat.

We have had a long period of cold weather here in Seattle and I have noticed that during this time two unusual behaviors are happening with my heating system:

(a) I have not see the AUX Heat indicator come on on the TH8000 thermostat. I have seen this frequently before and I took it to mean that the aux heater was helping the heat pump along. But I have not seen it at all in at least a week and I have looked frequently at the thermostat.

(b) There are times when the heat pump is not operating (I can see the fan blades stopped) but there is significant cool air (not icy cold but certainly not warm) coming out of my heating ducts. It is clearly being blown by a circulating fan in the system but there is no warmth.

I have looked as much as I can at the heating unit under the house and see nothing unusual. I checked the electronic air filter and it seems fine.

Any idea what may be wrong here? Thanks.

[HayZee518]

geo thermal temperatures are usually in the 58 degree range. so your system is extracting this 58 degree air from the surrounding dirt, rock. the aux heat should come on to supplement this geo thermal energy. I would check the heat sequencer first and make sure the breakers, fuses that supply the heaters are good. next check the sequencer itself if it is functioning. heat is applied in steps as it is needed through the sequencer.

[hvacwiz]

Originally Posted by HayZee518

geo thermal temperatures are usually in the 58 degree range. so your system is extracting this 58 degree air from the surrounding dirt, rock. the aux heat should come on to supplement this geo thermal energy. I would check the heat sequencer first and make sure the breakers, fuses that supply the heaters are good. next check the sequencer itself if it is functioning. heat is applied in steps as it is needed through the sequencer.

I believe from reading his post he has a heat pump, not a geothermal unit.

[whitedavidp]

Originally Posted by hvacwiz

I believe from reading his post he has a heat pump, not a geothermol unit.

You are correct. It is a heat pump.

[whitedavidp]

Originally Posted by whitedavidp

You are correct. It is a heat pump.

Thanks once again for your response. I found some info on the internet here <en.allexperts.com/q/Heating-Air-Conditioning-696/2008/2/Heat-pump-thermostat-control.htm>
and here <en.allexperts.com/q/Heating-Air-Conditioning-696/2008/2/Heat-pump-thermostat-control.htm>
that made me start checking things more carefully.

When this cold spell hit, I raised the temperatures on my thermostat schedules. I have never done this before. Under the previous schedule, I had simply raised the temp manually on the thermostat to what I wanted when needed. Thinking back, this is when I typically saw the aux heat indicator show on the thermostat.

So I just manually raised the temperature from its current setting by a couple degrees and indeed the thermostat does show the aux heat indicator. For this reason, I am thinking that the aux heater does, in fact, work.

However, I am not sure about if it is working during the defrost cycle of the heat pump. I only found out recently that there was such a thing. I may never have noticed it before because it has never been this cold this long since I have been in this house with the heat pump. Maybe the heat pump only has to go through a defrost cycle when it is very cold. Or maybe it does it frequently but I have only noticed it now because the air being used right now is so very cold.

Do I have to call in a pro to see it the thing is properly set/wired so that the aux heat comes on during the defrost cycle? Or is there some way I can check that?

Thanks and happy holidays to all!

[whitedavidp]

It has been suggested that one reason I am not seeing the aux heat indicator as frequently as before is that my Honeywell TH8000 thermostat is in recovery mode (which I have in fact seen for the first time since changing my schedules) and when in this mode, it may not ever call upon the aux heater. But I don't know if this will impact the use of aux heat during defrost or not.

Thanks for your time and responses. Happy holidays.