A couple of days after I returned from a week-long trip, I realized my
house had not yet cooled off, although it had plenty of time to have
done so. Before I left, I had set the thermostat to "off" since
nothing needed cooling. I put on my HVAC had and started sleuthing.
At the service panel, I saw that the breaker had tripped, when I reset
it, the AC unit came back on. So far, so good. No? No. There is
action but no cooling. Now what?
The AC unit is an older (10 years?) Lennox model in a Squirrel Cage
box. I noticed some of the fins were dusty to the point of being
partially blocked by Cottonwood tree fuzz, etc. I gave it a good
vacuuming and brushing, and made sure no obstructions existed. I
haven't yet opened the squirrel cage to check the fan and other things
in there, because I have no idea what is Supposed to be in there and
what it ought to be doing, except for seeing that there are no obvious
obstructions. The wiring & insulation is intact, nothing is kinked,
and there is no extra condensation going on anywhere. The blower's
filters have been frequently changed (due to extra dust in the air) and
the current filter is clean. There are no indications of any water
leaks at any point. No extra condensation. No ice, or freezing up.
Nor are there any "holes" in the ductwork, or any openings in the metal
other than those where the air intakes and registers are located. No
other leakages, in other words, so far as I can tell.
My home is being remodeled, so all lower level ceilings are open,
exposing all the ductwork. No evidence of anything unusual going on.
The furnace (thus the fan) are only 4 years old.....
One potential problem is that I think the contractors weren't always as
careful about covering the register holes as they could have
been....... I have vacuumed a LOT of drywall debris out of those
registers/intake openings. I don't see how anything could have gotten
to the AC unit, though?
The only odd thing I have seen is that the pressure relief valve on the
water heater seems to be dripping. This would otherwise be totally
unrelated, but since it occupies the same room as the furnace and air
handler, they might be in cahoots, or subject to the same illnesses?
The AC sounds to my ears, as though it is operating now with no strain.
Oh - BTW - it has a new dedicated circuit, for which wiring was
installed last summer. It worked just fine with the new wiring until
this past week, so that probably also is not relevant.
I have run out of ideas. Can anybody suggest some tips for further
sleuthing or action?