Four years ago I had a new unit installed and didn't have issues until recently. The TXV keeps freezing. The one in this picture is brand new, installed last after the first one kept freezing. My buddy that did the install no longer does HVAC. He suggested there may be a refrigerant leak. Any ideas what is causing this? The evaporator and condensor coils are clean and I just replaced the filter a few days ago.

Question from user shaggysflt at hvacadvice at reddit.com.

Answer:

Assuming clean filter, airflow is good meaning not a lot of registers closed off and blower is working. It's either low on refrigerant or the txv is bad. If he didn't use nitrogen when brazing I would say it's the txv. Have someone recover all refrigerant, pull a vacuum, to ensure no leaks, and replace txv then put all new refrigerant in.

Answer from user Firm-Introduction at hvacadvice at reddit.com.

thermostatic expansion valve keeps freezing