My heat pump has never been all that great, but near the end of winter
(here) it pretty much stopped working altogether. Here's the back-
story:

My house is about 1700 sq.ft (heated), and has a single heat pump. I'm
not sure what size it is, but it's a Bryant, and I'm wanting to say 3-
ton. It was installed in 2000.

It has worked fine until about 4 months ago, when we noticed a
ridiculously high power bill (roughly double the usual, which has
never been too cheap anyway). I started paying attention, and noticed
that the heat pump was pretty much running all the time, just to keep
everything at the right temperature.

After a couple of weeks, it went on a downward slope. I would have the
thermostat at 74, but noticed that the temperature never went above 71
or 72, and it was still running all the time.

I called out the company that originally installed it, and after a lot
of "I'm not sure" and "everything seems OK here," they finally
guesstimated that the problem is what they called a "UV Valve." The
tech said that all of the voltages were right, and everything was
kicking on correctly, so this was literally the only thing left that
it could be. He called the home office, and they sent out another guy
a few days later to confirm (I wasn't here when he came to confirm,
but he left me a voicemail).

Here's the problem: the estimate to replace this UV Valve was a
whopping $950! The original tech said it would probably be $600, but
the tech that came to confirm when I wasn't here was the one that gave
the higher quote. This makes me worry that (a) they saw my nice house
and cool car in the garage, or (b) they found out what business I own,
and think that I have money to pay extra (which I don't have, thanks
to the nice house and cool car in the garage!)

I don't want to go in to too much detail, but I also had to have a
minor repair done to the heat pump after I bought the house that makes
me question the quality of the original installers work. It seemed as
if they installed something that they knew would fail, possibly with
the intention of getting paid to come and fix it at a later date. I
can explain more if necessary.

So here are my questions:

1. Based on the symptoms I posted, does the diagnosis of a faulty UV
Valve seem reasonable?

2. If so, would an estimate of $950 seems fair to replace that valve?

I hate to say "please reply urgently," but the temperature here is
going to be close to 95 by the weekend, so I have to decide pretty
quickly whether to pay someone else a $100 "diagnostic fee," or to
just trust this one. It turns out that every HVAC guy in the county
charges a minimum $100 fee, just to come and look at the darn thing!

TIA,

Jason