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Gas fluctuation

Simply Rad
Simply Rad Member Posts: 184
Had a service call today for a Burnham power vented boiler. The boiler was moaning and groaning.  I ran some tests and found that the inlet flowing gas pressure was fluctuating.  The static pressure was 8" and the flowing was pulsing between 5.25"-7.3"  THe outlet pressure was pulsing between 2.75-3.7"  I checked the gas inlet into the valve and found no debre.  When I tested the unit there was no other gas load.   I then called the gas company to check the meter.  I wasn't there when he showed up.  He meet the homeowner and tested the meter and found no problems?  Could the gas valve be bad and cause the gas supply to fluctuate?  Thanks for your thoughts and happy holidays

Jeffrey Campbell


  • Tim McElwain
    Tim McElwain Member Posts: 4,621
    Was this a high pressure

    system with a regulator at the meter or is it low pressure? It sounds like a low pressure system as you had a static pressure of 8" W.C. Was the fluctuation evident on any other equipment?

    What is the make and number of the gas valve?
  • Jim Davis_3
    Jim Davis_3 Member Posts: 578
    gas pressure

    The fact hat the pressure into the valve was fluctuating shows the problem on the supply side.  The pressure drop on the inlet of a gas valve when the valve opens should not be more than 1/2" with 1" being the maximum when enough pressure is available.  If the problem is not the meter then the piping is too small.  Of course I have never seen piping change its size once installed.  The fluctuation has to be from the meter.
  • Jesse89
    Jesse89 Member Posts: 1
    pressure readings

    Sounds like water or some kind of liquid is somewhere either in the house piping or in the gas company piping. Any type of a dry blockage would show a lower operating pressure but it shouldn't fluctuate. A wet blockage would have your reading fluctuate. Have the gas company come back and have them take reading at the appliance, on the inlet and outlet of the meter and at the head of the gas service if its low pressure.
  • Tim McElwain
    Tim McElwain Member Posts: 4,621
    How did you

    make out?
This discussion has been closed.