Lennox Heat Pump needs TXV
We have a Lennox HP26-042-12P Heat Pump that needs servicing. I'm just wondering if our A/C contractor is being straightforward with us.
Two weeks ago, all was working fine with the system, and while replacing a sheet of siding on our home, I very stupidly drove a nail through the A/C supply. In a matter of seconds, it drained all the coolant from the system. Yes, I'm an idiot, which I keep reminding myself, although I'm usually a pretty careful do-it-yourselfer. Anyway, the A/C contractor came immediately, fixed the puncture hole and completely recharged the system. But, another problem has since developed...
In north Florida, we can still have some cool nights, so I've recently been alternating heat at night and cool during the day. As of a few days ago, the heat pump/compressor failed to come on at all, in either heat or cool mode. Another call to the technician revealed that we need a new TXV valve which, unfortunately, means losing (and replacing) a lot of the coolant we just replaced with the previous repair.
Before this valve stopped working, the only thing unusual I noticed after this incident/repair was that the heat pump was operating a little unusually...it would come on and heat the home, then turn off while the blower continued to circulate (all normal), but then the heat pump would then turn on again for a few minutes and turn off again. I didn't notice this happening before the service call, and I didn't notice anything unusual with the A/C.
My question: is it just incredibly bad luck that this valve has failed now, so soon after my mistake, causing us to have to pay to refill the coolant twice (over $700 a pop)? Or, is it possible that the valve has failed as a result of something done/not done during/before the re-charge?
Of course, they're trying to talk us into a new system, but we're not ready for that as the Lennox is only about 9 years old.