I have an older heat pump with a Honeywell thermostat that starts blinking the green auxilary heat light when running the heat. I can hear a clicking at the compressor that coincides with the light. Any ideas?

Could be the unit going into defrost mode.

Auxiliary heat is usually the heat strips turn on. Aka meter spinners

The aux light is not just on. It is blinking and something is clicking on and off outside. The temperature was 45 degrees out and 68 in.

One of the Batey boys will be along shortly with the answer.

What kind of System do you have? Is it an older Mercury Bulb tstat or newer digital?

A lot of older units have an ability to send an alert to the tstat via the defrost control board. It usually results in the red light flashing, but I suppose it could be green too.

Is the clicking that you hear-

1. An audible clicking of a relay? click click- - - click click- - -etc.
or
2. Is the outdoor system actually shutting on and off?

Does it do this every time the heat is on?

It’s an older system prob 20 years. It is an audible clicking that coincides with the blinking of the green led. The outdoor system continues to run but I can hear the click from inside standing at the window nearby. It just started Saturday and I can move the tstat setting lower and it quits.

What brand is the system? Trane?

Honestly don’t know since we just bought the vacation home. The sticker on the side is faded and I can barely make out a serial number.

10-4. Either way, a lot of systems can send an alert to the tstat, via the defrost control, that results in a flashing aux.light. You’d be able to hear the relay clicking in and out as well. It sounds like you may have that going on, but that’s just a guess with limited info.

Several things could cause the control board to send the alert signal, if this is the case.

You shouldn’t get any kind of clicking in and out/lights flashing during normal operations. May not be anything major, but I’d still call the Man.

If you are able to find a Brand name/ model or serial number at any point, post it up.

It’ll be the 22nd before I go back but I’ll def try to get some info. I can hear clicking inside around the air handler also but it’s not as loud as the outside unit.

I finally made it back down to our condo and got the serial number. 4895E19786 if anybody could help me look that up.

Model number and make would be more handy if you got that.

Or at least a make with the serial #

I can’t find the make. Here’s the model # HA1CJ024-B

I think thats a bryant