Heat Pump Pumpdown AND Recovery.
Yes, I mean "AND."
Maybe I've never pumped down a heat pump unit before.
I would have thought I have, but if I did, I didn't have
problems and didn't think much about it. Likewise for
But yesterday, I was involved with an air-handler removal so
I ended up attempting both a pumpdown and a recovery
on a split heat pump. (Goodman. No, I didn't bother
with the model number.) Ambient was about 60 F. Inside
dry bulb was maybe 65.
First, the low-side pressure would not fall below about
30 psi for at least 10 minutes so I decided something was
up. I called up two seasoned techs and they thought the
low ambient, 60 F, should not matter. And yes, I had
the system running via the tstat in cooling mode with
the high-side service valve tightly closed--at least the
allen bolt was tight. So after not having any clues, I
decided maybe the service valve was leaking and decided
to do a recovery. (The installers were anxious to remove
the old air-handler so I had to do something resembling
My Appion G5 is usually really fast, but yesterday the system
finally got down to about 25 psi and sat there for maybe a half
hour. There was some icing on the suction line
and a bit of frosting on the reversing valve. Shuttting it off
for 20 minutes and then starting it back up seemed to
stir up some progress, so the pressure dropped to about 15 psi
then went back to 25 and then slowly worked back down.
What am I ignoring? I figured that with the liquid line
service valve closed, the heat pump orifice played no
part in anything, so the whole thing should be just
like an A/C-only system. Obviously I'm doing some
Thank you for any enlightenment.