archibaldtuttle
10-06-2008, 04:14 AM
OK, so I got the new 7.5 ton replacements on the way for the divinely inspired system trouble I spoke of earlier.
I should be able to readily determine whether the expansion valve is blocked, one suspicion I had on one circuit (btw it is thermostatic with a capillary running to a sensor affixed to the suction line at the exit from the evaporator to adjust superheat) by blowing a little nitrogen through the high side after I remove the old drier. But I'm wondering if there is a procedure to test the general operation of the valve. I suppose I could apply some ice to the probe and see if the same nitrogen delivery pressure gets a different result, but just wondering if there is any simple test, and/or if I should just replace the things since they are 15 years old.
Thanks,
[I'm] Brian [and so's me wife]
I should be able to readily determine whether the expansion valve is blocked, one suspicion I had on one circuit (btw it is thermostatic with a capillary running to a sensor affixed to the suction line at the exit from the evaporator to adjust superheat) by blowing a little nitrogen through the high side after I remove the old drier. But I'm wondering if there is a procedure to test the general operation of the valve. I suppose I could apply some ice to the probe and see if the same nitrogen delivery pressure gets a different result, but just wondering if there is any simple test, and/or if I should just replace the things since they are 15 years old.
Thanks,
[I'm] Brian [and so's me wife]