Do you need to evac the system when you replace the txv in the air handler or is there some type of cut-off switch that is present?

Yes, the tech (as the other person replied) if qualified and actually does the job right will do this.

Pump down the refrigerant into the condenser (saving you from having to buy new and very expensive r-22)

Change out the indoor txv (I believe you said indoor - outdoor txv changes things $ wise big time)

Add a liquid line filter dryer

Braze in all connections

Leak test with nitrogen

Vacuum to at least 500 microns once, maybe twice with a nitrogen blast in between

Then open the valves and you should be back in business.


Just be sure that is what is going on: TXV's can be misdiagnosed very easily. Did he say exactly what brought him to that conclusion?

RE new unit. You are in the 'twilight zone' unfortunately. Past 15 years you are money in the bank every day as far as I am concerned. If you go new (and I hate to say it) go 410a. It is just the way the man is making things go as much as it bites.

Here's a vid on TXV's this one is an indoor and compression fittings, some are sweat in fittings.

TXV tour and problems - thermal-medics FREE online air conditioning repair and info site from Phoenix AZ

One on r-22 vs r-410a

R-22 vs R-410a Head to head!! - thermal-medics FREE online air conditioning repair and info site from Phoenix AZ

Good luck