heat pump compressor stops running when heat strips activated

[EbS-P]

I’m assuming you are using communicating mode. ? It uses a defrost timer no ice sensor?. And has a 37 F stage one lock out.

" the fan doesn't run when in defrost mode, which I guess makes sense. (The reason I thought the compressor wasn't running was looking out the window and seeing the fan standing still - didn't notice if I heard the "growl" of the compressor itself or not).

defrost keeps the circulation blower on. Stops the condenser fan. Keeps the compressor on. This should all be handled by the unit logic not the Tstat. The train Tstat I used to have might say the unit was busy or something like that.

I don’t think the comfort system setting have anything to do with it.

My unit only defrosts below 40F.

My guess is you were seeing defrost cycles. No condenser fan and everything is running fine.

Side note the fan profiles are nice you should I like the ramping ones. I’d choose D.

 

[RustyShackleford]

I actually wired it in "legacy" mode (see image in my OP) because I figured the fancy Honeywell thermostat was smarter than the unit's algorithms (for example, the Honeywell knows what the indoor temperature is, the heat pump does not).

But yeah, I think I was seeing defrost cycles; it was definitely below 40 degrees and we were having some precip too.

Sorry for the chase of zee wild goose, and thanks everyone for helping here !