Hello. I have a 12 year old Bryant heat pump (3 ton 661A model) that gets
covered with ice a few times during the winter. It's done it twice so far
this winter. It obviously has something to do with the unit not defrosting
properly, but the HVAC guy I've had out to check it out (several times)
always shows up just after I've defrosted it (by just letting it thaw out).
Since it's not iced up while he's there, he says he can't check out the
defrost control board(?) or other things that could be bad and causing the
problem.

I've read a couple of web posts describing this same model heat pump, and
the person said he replaced the defrost control board, which fixed his
problem. He also mentioned the reversing valve, but ended up not needing to
replace that. Are these parts things a tech should be able to swap in and
out easily? Or are they expensive?

I do notice this unit making a clicking sound (rhythmically, every second or
two) every once in a while. But usually it sounds pretty normal. Could the
clicking be related to the defrosting/reversing thing?

Since the heat pump is 12 years old, could it be close to the end of its
useful life? It'd be a shame, since it seems to do a good job of heating 95%
of the time; it's just the iced-up times that make me need the aux heat for
a day or two to defrost it. Any advice? Thanks.


F