So here we are, it's two years later and it appears that the sliding orifice (aka Flowrater) in this heat pump has jammed once again after a long summer without use. In heating mode, there is plenty of heat in the refrigerant supply to the AHU, the line out is cold and there is very little heat output in the air coming out. I can only assume the small amount of heat output is due to a lack of refrigerant flow.
I haven't jumpered to test cooling but I seem to remember these exact symptoms last time.
Assuming that it is the same waxy crap causing the issue:
-Does anyone have any ideas what could be the source of the waxy crap?
-One of the previous posters commented that a dirty coil could result in high ref temps. Is there a known upper temperature limit for POE oil or any other R410A additive that I need to beware of once back in operation?
-Any success on freeing up the slider without sucking down the system and pulling it all apart?