clogged txv

[gasngo]

I have a small undercounter freezer (35 oz 134A) that seems to be starving. Suction pressure is about 5-7 pounds but only back side of txv and about 3 or 4 Ubends are frosted up. Box would only get to 22-25 degrees. Sight glass is full and no other problems can be found. Put a hot rag on tvx bulb , but did not change anything. Coworker beat on txv ( AC guy) and did get a little better than when we first started. Its a bear to get to and brazed in. I was thinking about blowing backwards through it from suction side with access from service valve ports, with either nitrgen or 134A. What are your thought on this ? Thanks...... Gasngo

[Magoo]

The TXV needs replacing, they don't last for ever. Doubt if is blocked so long as they is a filter drier in the liquid line before TXV.

[gasngo]

There is a coil of 3/8 suction line about 5 feet long that is after the dryer. Every time the condenser is moved I'm sure some junk gets broke loose. That's why i wanted to blow it back through the liquid line.

[tonyelian]

hi
it could be small orifice too

[chilliwilly]

Only 35 oz, that's just over a KG, I'm suprised its got a txv. It sounds like the valve part is working as you found out when your mate brayed it. Why not change the head on the sensor before you open it up, if that doesn't work then you'll have to pump down, remove and clean or replace whole txv unit.

[Tankerbox]

wrap a hot ragg around the txv body. if you see or hear any change. you have moisture in the system. thus frezzing up the txv. system has to be dry. good luck

[coolhibby1875]

if it didnt work by heating the valve, but did by hitting it, it appears there is debris, if its a original sealed system, its likley the drier has broken up and clogging the valve, best bet, decant gas change drier give it a good vac and weigh in gas!!

[pepsiqazi]

check super heat and sub cooling