Good afternoon. I've been experiencing some high temps in the house during the day and a freeze up on the outside unit the other day. I called the service techs and they went through the normal diagnostic routine. He determined it was a bad TXV valve but at $1100 to repair I'm skeptical. I have a Carrier Heat Pump. Here's what he found:

When he hooked the guages up outside he found low pressure on the blue guages (low side?) and high pressure on the red gauge (high side?). Did I get the guages right?

He cleaned all the coils and nothing changed.

Went to the attic to check air pressures of intake and exhaust, all was normal.

He said it could be too much freon in the system so he went back to the compressor outside. He hooked up his thermometor to the larger diameter tubing (the one covered with insulation) and found the temp difference to be over 30 degrees from the reading on the red gauge to the reading on the thermometer. He said it was supposed to be around 12. I have a 12 seer unit. He said that the freon level was fine.

His diagnosis is suggesting a frozen txv valve or some other blockage that is keeping the freon from flowing.

Quoted me $1100-$1300 to repair. Is his diagnosis viable and is there anything that I can do to fix it? He never checked a reversing valve. Do I have one with a TXV valve?

Thank you for your time!

Txv bad or stuck will cause low suction and high head pressure. But they only cost about $45

I knew they weren't too expensive. Just another HVAC company tacking 300-400 percent onto the service.

I had the same problem. AC unit runs, but does not deliver cold air. The technician checked a few things and said that the TXV valve is not working fully or properly. He added some refrigerant (Freon 22) and that seemed to only make the situation marginally better. He quoted around $1100 to go through his service company, but said he could do it for me on the side at half that price. I am very skeptical, still wondering what to do.

In all my years of service I have probably only replaced 20 or so expansion valves and most of those was just a power head replacement. Now it seems like they are dropping like flies.

Makes me wonder if they are really all bad or if the factory has really started to make them cheap. My friend at Sporlan/Parker says they are not being made cheaper and there real return rate is very low. I say real return rate because they test the ones that come back under warranty and out of those only about 2% are really defective.

Kind of makes you wonder if the service people really know what they are doing.

TXV's will cost you money... If the technician does it correctly the refrigerant HAS to be reclaimed, the valve replaced (along with in line filters ),leak checked and a vacuum pulled.Then NEW refrigerant must be added. NO decent tech will use the old refrigerant.This is due to contaminents which may have been in the system and MAY have been the cause of the TXV failure.
The cost of R22 and/or R410a, the labor time and equipment used make it a costly repair.