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loop under the pressuretrol

jp741 Member Posts: 31
How would I know if the loop (syphon) under the pressuretrol is operating correctly or is clogged.


  • BobC
    BobC Member Posts: 5,477
    How to check

    How is the system working now? Is there more hissing or banging?

    On a normal cold day it is not unusual for a steam system to cycle on pressure. That means the system will run until it hits the upper pressure set point and then turns off, after a couple of minutes the system turns back on again until the pressure rises to that upper set point. This goes on until the thermostat is satisfied.

    If you suspect the pigtail is clogged you have to remove the pressuretrol and see if you can blow into the open pigtail pipe, make sure the circuit breaker to the boiler is off and that the boiler is not hot. There will be some resistance because of the water in the pigtail but you should easily be able to overcome that. Also if you look at the brass fitting on the pressuretrol \you will see a small (1/16") hole at the base of the brass fitting, that has to be clear.

    Post some pictures of the pigtail and the pressuretrol so we can see what your dealing with.

    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
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