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pressuretrol (differential) im confussed

jesse the great
jesse the great Member Posts: 72
in THE MAIN WALL
the pressuretrol on my boiler has a main pressure and a differential. the differential is subtractive (Great)
the main is set at 2psi the diff. is set at 2psi so im thinking its at like 0 psi but when the boiler fires up the pressure gauge reads 7 psi what is the normal settings suposed to be. when people tell me about cut-ins & cut-outs it really confusses me

Comments

  • Mellow_2
    Mellow_2 Member Posts: 204
    are you sure it is subtractive?

    The cut in is when the burner turns on and the cut out is when it turns off..... So if it is set 2+2=4 that can show seven with presuretrols. they are just not that acurate when they show settings but if this is a standard control (or one that adds) try cut in .5 psi and a 1 psi diff. The gauge could be off a pound or so and so can the control. That is another 2psi 2+2+2=6 very close to seven. good luck
  • DanHolohan
    DanHolohan Member, Moderator, Administrator Posts: 16,611
    The Main

    should be 2 psi and the Differential should be 1-1/2 psi. It sounds like there's a clogged pigtail here, or a defective pressuretrol.
    Retired and loving it.
  • David Efflandt
    David Efflandt Member Posts: 152
    Either gauge or pressuretrol is inaccurate

    Something is either wrong or blocked for your pressuretrol or pressure gauge.

    My pressure gauge was on a snubber that was blocked, so it was just reading trapped heated air pressure in the snubber instead of boiler pressure. With that fixed and switched to a pressure/vacuum gauge, I did find that my pressuretrol was working properly, kicking out before it reached 2 psi and back on before dropping to 0. But I have a pressuretrol set 0.5 psi cut-in and 1 psi additive differential cut-out.
  • John Shea
    John Shea Member Posts: 247
    Why don't they make..

    a pressure guage that measures in ounces, just as a vaporstat would control in ounces?
  • DanHolohan
    DanHolohan Member, Moderator, Administrator Posts: 16,611
    They do.

    It's called a diaphragm gauge.
    Retired and loving it.
  • jesse the great
    jesse the great Member Posts: 72


    thank you dan..the pig tail was clogged. i could'nt see it in my minds eye. i cleaned the tail and looked into the pressuretrol and didnt see any debris yet my gauge reads close to 5 psi now so im going to replace it and see what happens just wanted to say thanks
  • Glenn Harrison_2
    Glenn Harrison_2 Member Posts: 845
    John, here's a link to a whole page of them.

    http://www.gaugestore.com/lowprgalomo.html
This discussion has been closed.

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