I have a heat pump A/C system in my townhouse. What I've noticed is
that if I leave the A/C on all day, eventually water starts leaking
out of the unit and into my closet one floor below the unit.
When an A/C technician came over we took the door off the unit and
poured tons of water into the runoff tray inside, but none of leaked
out. It all properly drained out the primary condensation line. We
couldn't figure it out!
Finally one day after the A/C had been running a lot, it began leaking
again. I quickly went up to the FAU (is that what this thing with the
blower and filter and radiator is?) and took the door off to see the
source of the leak. It was coming out of the runoff tray.
The weird thing is, the second I took the door off with the A/C
running, the whole runoff tray emptied via the primary condensation
What I've determined is that the fan inside the FAU is spinning so
fast that it's creating a vacuum inside and it's not letting the water
drain out properly. That's why when I took the door off and the air
pressure equalized, it all drained out.
Now I manage to avoid more water damage by turning off the A/C after
it's been running for a while to allow the air pressue to equalize and
to allow drainage.
However, I'd like to get this fixed so that I don't have to worry
about it. Why would this happen? Is it a design flaw? What can I