Read and understand. A TXV will NOT work w/o a full column of liquid, TXV’s generally do NOT go bad...it’s hard to damage a hardened steel rod that moves the thickness of a quarter. Power elements will however fail (they’ll loose charge, leak, etc) and if the TXV has a fixed power head and it fails you’ll have to replace the entire valve. As long as the TXV kept clean from debris, full column of liquid along with a working power head the TXV will have a happy life. But wait there’s more remember the four major components? They have to be clean and in good operating condition if any of the other 3 are not in good condition or fail this includes air flow of 500fpm across the evap and 500-700fpm across the condenser along with proper sloping and oil migration and refrigerant off cycle migration then the TXV is in jeopardy. The TXV becomes a victim of many assaults including oil slugging at startup moving at excess of 1500 FPM hitting the TXV head on (hydraulic hammer) so to speak, multiple instances of this will cause imminent failure. You found the TXV “bad” and replaced it but did you fix the problem? Back to the basics, clean and maintained filtration, clean coils, proper air flow, sealed dry and properly charged system, full column of liquid (sight glass), debris protection and drying (txv screen, filter drier), proper piping techniques (slopping, trapping), refrigerant off cycle migration prevention (solenoid valve, CCH), good clean power and controls (smooth instant starts). This a long subject, so long a 100 page book could be published on the domino effect from major component failures including the infamous “flashing”! 90% of what we face is something we should have done and didn’t or something someone else did or didn’t do. All components in HVAC shake hands with each other once the grip slips it may not be the first handshake you come to that’s the issue it’s not always the loudest personality in the system that’s screaming for help that is the problem. Typically the silent ones are at fault and caused the breakup. You have to find the silent issues to fix the loud ones! I know I didn’t cover it all but hope this will change your perspective. Stay frosty friends! #teachme

Posted by Ty-Rap Rock at 2021-03-08 16:57:12 UTC