06/11/2026
The facility really needed this Rooftop unit to be working.
This is the procedure I will perform to try to get a failed TXV to function again until it can be replaced.
1) If the sensing bulb wasn't obviously broken, I will first start by cutting the equalizer line to confirm that it is not plugged (refrigerant will spray out from the tube welded into the suction pipe).
Then, I pinch off and weld shut the tube soldered into the suction pipe and then extend the TXV equalizer tube to a piece of 1/4" copper that I will flare and connect to the suction service valve with a swivel tee.
2) If that is not the remedy, I will cut the capillary tube near the TXV sensing bulb (this one broke as I handled it). The charge should be released if it did not leak out. Then I will pull out the old tube and reconnect the TXV Dome capillary tube and add a schrader stem to add a charge.
This will not be perfect, however, it should push overcome the spring and open the needle valve in the TXV.
In this example, the suction was a bit low and superheat a bit high, however it was close enough to keep the system, online a few days and it even had a decent temp split 👍
