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Bryant Evolution question

Posted by bri0822 (My Page) on
Sun, Oct 30, 11 at 10:11

I have a question about the electric backup heat on my 2010 Bryant Evolution heat pump -

When the temp is below 30, the heat pump runs more or less continuously with the compressor on low stage, sometimes on high stage, and the backup electric heat only kicks on briefly during the defrost cycle.

But, when the temp is about 35 to 50, the heat pump will first run in low stage, then high stage, and then the backup electric heat will then come on for about 5 to 7 minutes. The system then stops and will not run again for about 1 to 3 hours.

Does anyone know if this is how the Evolution thermostat should be working? I thought the backup heat would only come on if the heat pump couldn't produce enough heat. My electric bills are low so it looks like the system is working well, but the backup heat activity caught my eye...

Follow-Up Postings:

RE: Bryant Evolution question


Assuming your description is correct and you have no setbacks and recovery, then I would say your system is not operating correctly.

And your electric backup/auxiliary should be locked out at near your balance point. Electric backup should not be operating at all for temps above the balance point except for defrost mode.


RE: Bryant Evolution question

Thanks IMO, and yes, there was no setback/recovery when I was seeing the aux. heat come on. I also noticed that when the heat pump is running without aux. heat, the air temp at the wall registers is not as warm as last year. I remember last winter, even when temps dropped below 20, the heat pump was still delivering warm air without aux. heat.

I'm going to call for an HVAC tech to come and look at the heat pump, but do you have any ideas on what may be causing this problem? I'd like to have some idea of possible problems for when I meet the tech.

RE: Bryant Evolution question


Are you certain you are not confusing a defrost call and aux heat coming on at temps above freezing?

Obviously defrost mode should be checked as well as defrost settings.

Aux heat should be locked out at 32-35 deg for all but defrost calls and
emergency heat. No normal backup period. Tech should show you how to do this with Evolution controller. You do have outdoor thermostat?

High stage of heat pump should be checked to see that it is operating correctly.

You have identified a possible problem; tech will need to find cause and repair, etc.

Post back and let us know what he finds.


RE: Bryant Evolution question

I don't think the aux. heat I was seeing was a defrost call. I have noticed other defrosts, especially at colder temps, and when this happens the electric heat goes on stage 3 for the duration of the defrost (usually 1 to 3 minutes). I also noticed a different sound from the outdoor compressor during defrosts, which I do not hear in the situation above.

In what I was seeing above, the electric heat comes on stage 1 and usually goes for 5 to 10 minutes, then reverts back to high stage, the low stage, then off. I think I have an outdoor thermostat but I will ask the tech about that too.

Many thanks for your help, I will follow up after I see the tech.

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