I have two identical 4 ton units, 1 upstairs and 1 downstairs. The
downstairs unit runs like a champ, however, the upstairs unit hisses
at the evaporator. The house is new (3 years old) and have had the AC
company that installed it take a look at it several times. It is an
intermittent problem, and seems like every time they come out it runs
quiet. In March the compressor died, and was replaced. I still have
the problem, however, the hissing has become louder and the compressor
will shut off violently (I hear a thud as if the pressure was way too
high.) The only other clue to the problem is that it hisses all the
time but tends to get louder in the afternoon and peaks in terms of
"loudness" around dusk (if it occurs.)
I can see myself having to replace the compressor again if the problem
is not rectified. Any ideas what this could be? I need some advice
on how to direct these repair guys, or at least be armed with some
knowledge when I shop around for a new AC repair company.
If "YOU" have to be the one to tell a HVAC company how to repair your
unit then you have called the wrong company. You should only have to
describe the problem and any related info. Then its up to a competent
company to do the repairs.
Id be concerned with refrigerant charge, refrigerant metering, proper
installation practices and of course, proper ductwork, equipment and
There you have it. Now get busy.
Quite frankly - you need 6 vital signs for a competent air conditioning tech
to tell what's "what" with your unit. Get those readings and head on back
to alt.home.repair and I'm fairly certain someone will be happy to answer
your needs on this issue.
you didnt mention age of this particualr unit, but it sounds like it has a tev
that may be the hissing you hear .
and that may be directly related to your problems , but -
we can't fix it from here , we can't troubleshoot it, hell,we can't even see
as someone has noted , if "you need to direct" your repair company then you
should be looking for another , we can't help you
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