Based upon his estimate of a replacement, I would also question his diagnosis. Sounds like he just wants to sell you a new system. Definitely get a second opinion - could be a bad reversing valve. Regardless, shouldn't cost more than about $400-$700 to replace.

I would say your diagnosis needs to be confirmed first...I have my doubts but TXVs do go bad...3K is ridiculous...you never said the age of your system...

IMO

If the compressor doesn't turn on while in heat pump mode this points to possible control issue / wiring problem or control part failure.

To diagnose that a TXV has failed the system has to be run to be able to diagnose that.

Cost to repair can vary greatly without knowing what refrigerant this system holds as repair to the refrigeration system will likely require removal of all refrigerant with repairs made to condenser side of the system. While a refrigerant can be recaptured there are risks and legal requirements required to do this accurately without introducing acids and other contaminants to your system, most often virgin refrigerant is used to reduce / eliminate this risk. This is what drives up repair costs. The flip side is if you just do it carelessly and reuse the old refrigerant the repair may be short lived and cause other failures such as compressor failure (burn out) due to acids in the refrigerant.

This could be the reason for the high price. R22 Freon will no longer be produced as of Dec. 31, 2019. What is allowed to be produced up to that point is a fraction of the demand for this refrigerant (R22).

A 10 year old system is not that old and worth repairing, but not at a cost $3000. Like the other posters, I am suspicious of the diagnosis. Get another opinion on the repair from someone you trust.

Thanks to you all for your thoughts. I don't know whether to be relieved or not that my intuition that this was possibly a rip off was correct! We have another company coming out here today. I don't know that I can say for sure that I trust them -- we haven't had to have any repairs done on our heating/cooling since moving to the area. But, we'll see what the second company says.

a 10 year old system is border line repair versus replace debate and depends greatly on what is wrong with it and what refrigerant it uses. Simple reason is there probably is no manufacture warranty left / in some cases manufacture warranty length can be as few as 5 years if the home was recently purchased.

If it's merely an electrical problem (control or other issue) that can be fixed without needing to access refrigerant circuit then go for it.

But if the problem has to do with refrigerant circuit and the refrigerant used is R22 Freon, you are probably better off replacing it. Because R22 Freon costs are only going up from here.

Back in the day when R22 Freon was cheap this problem was a no brainer always repair on such a young system, but those were the olden days. Things are completely different now.

As an example a TXV problem inside heat pump condenser all the refrigerant would have to be pulled from the system to make the repair. As stated before, the compressor must run to be able to diagnose a faulty TXV.

If you plan to sell the home soon -- like within a year the equation changes a bit.