Avoid Noise reduction mode when it’s cold outside!!
I’d been playing with Noise Reduction mode the other week and forgot to turn it back off.
So after coming out of the hot water run at 3am (to 1pm, purple highlight) the heat pump wanted to go full beans on the compressor at times (upto 110 rps), but NR mode capped that at around 60-80 rps.
See ebus trace of the compressor speed from home assistant.
Capping the compressor meant the heat pump couldn’t achieve target flow. ie, couldn’t reach the grey line. So the internal temp wouldn’t rise as fast as it should.
Also noticeable was that as well as defrosts being more frequent. The were also less useful. I watched the back of the unit during and after a defrost and many of the fins didn’t clear. Like the compressor limit also transferred to defrost?
So I ended up in some sort of defrost doom cycle where it never fully recovered from defrost to defrost
You can see at 2pm (green highlight) after the afternoon hot water run where I disabled all noise reduction schedules, the heat pump got right back to normal service, got back to target temps and the internal temp started to rise again.
And the defrosts did their job by clearing all the fins. The defrosts then became less frequent.
BEWARE OF NOISE REDUCTION MODE!!
Especially when it’s cold outside.
