Don't know much about A/C since I live in a temperate clime, but g.f.
lives in a hot place. Tenant in her rental house said the A/C wasn't
working. Tech went out and replaced the starting cap for $120. Unit
worked one day and stopped. Tech says the compressor "shorted out." Cost
for a new one is $800 installed.
Temp there now is 105 so don't have a lot of time to kill doing
research, but would appreciate feedback.
1. Do compressors "short out" or is that just a mis-used term for
"stopped working for some reason?"
2. What is the likelihood that the tech screwed something up while
replacing the cap?
3. Is it likely that there's a compressor fault that can be fixed
without replacing it?
4. Are the compressor motor and pump separable?
5. Are used compressors available? Rebuilt?
6. Why did the unit run for 24 hours with a new starting cap if the
compressor is faulty?
7. Any other questions for the tech or suggestions for the g.f.
Absolutely no interest in spending any more than absolutely necessary to
make this thing limp along for a few months, as the house is going up
for short sale within a few weeks.
ONE HUNDRED AND TWENTY DOLLARS for a five dollar capacitor? Anyway, my
uninformed answers to your questions:
#1 "Short out" - I guess it could happen, but I never heard of that nor know
how one would test for it.
#2 "Tech screwed up" - Possible. I'm not sure how.
#3 "Compressor fixed?" - Again, possible. Depending on what's wrong. You
can't really FIX a compressor, the whole thing is sealed, but the problem
could be elsewhere in a place that CAN be fixed.
#4 "Compressor and 'pump' separate?" - No. It's one sealed unit.
#5 "Rebuilt units available?" - Never heard of one
#6 "Why did it run for a day?" - I don't know.
#7 "Additional questions" - Why are you using this tech?
I think it's POSSIBLE that a defective cap put such a load on the relay that
it burnt the points. The capacitor and the relay are about the only
serviceable parts IN a compressor unit.
For a tech to come over, daignose it and replace a cap, that
sounds like a reasonable charge.
It happens. Just like it can happen on any other motor. Insulation
on the windings fail and eventually short, producing more heat,
more failure, until it's cooked and kaput.
Probably not. It could have been it was starting to fail and
having difficulty starting and he concluded it was just the
starting cap, but it turned out to be much worse.
It's a sealed unit and if the compressor is shot, no fixing it.
When getting this fixed, another consideration is that the
failed compressor could have sent burned crap through
the rest of it. That has to be carefully evaluated and
flushed out if necessary or else you could wind up with
more problems down the road.
Meaning it's a good time to consider other
alternatives, like replacing the whole AC sytem, ie entire
condenser and evaporator. Depending on the age, efficiency
of the old one, rebates from electric company, etc, that
could be a more logical choice. Perhaps for not a lot
more you could wind up with a whole new system.
Years ago I had the compressor fail on a system I had
that was only about 7 years old. I elected to just replace
the compressor because of the age of the system and
I had a guy who could do it for only $600 at the time.
Likewise. Mine went blooey after Hurricane Yikes. My son's neighbor, a
Guatemalan, moonlights in the repair business. He contacted one of his
expatriate contrymen who makes a market in used equipment. I got a two-year
old condensing unit (Rudd) installed for $700... at eight o'clock at night.
Well, you're right of course. But that's why so many hang out here to learn
how to do things on our own.
In the instant case:
Ten minutes to remove capacitor
Thirty minutes to meander to Grainger's for a replacement (~$10)
Ten minutes to install and try the new cap
So the gamble is an hour of my time, plus ten bucks, vs $100. (Already have
That's pretty reasonable. You don't mention the tonnage but even a
couple tons is probably $6-700 for the outside unit at his prices.
It's been my experience that you can double the equipment price to get
a good idea what it will be installed. The 5 year warranty will help
with the sale.
There are many service people that do not have a good idea of how to repair
anything. The just throw parts at it and finally hit on the part that fixes
If the service man does not know the differance between an open and a short,
I think I would look elsewhere. The refrigeration part is simple, it is the
contrlos in the newer units that are complicated. If it is an old system,
most anyone can get it going.
I work as an electrician/instrument technician in a large company. There
are about 25 in the shop. Out of them , there are about 3 that are very
good, 5 more that can do a fair job and the others just change out parts and
hope they find the correct one.
A few years ago my heat pump would not go into a defrost cycle in the
winter. The repair man came out while I was at work. He replaced the fan
and capacitor for about $ 350. I did not think it was the fan as it was
running but there was ice on the outside unit. Called him back and he said
something about the electronic board and left. Said he would be back when
he found one. I called him when I got home and told him to just forget it.
AS the unit was about 15 years old, I went with another company and had a
new unit installed. I know that is not a good option for a house on a short
For what it's worth the fan should not run while the unit is in
defrost. That is controlled by a relay on the defrost control board.
I have had a case where a short in the dual run cap shared by the fan
and compressor caused the fan to continue to get power even though the
defrost control board had turned it off. But in most cases the fan
relay on the defrost control board is bad if the unit switches to cool
mode but doesn't turn the fan off when forced into defrost mode.
The defrost control board simply switches the unit back to cool mode
and shuts off the fan. Heat from inside the house is used to defrost
the outside coils. How the defrost control board decides to do that
varys. Some are simple timers. Others have various temp sensors that
detect when the outside coils have started to freeze.
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