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Gauge movement

jp741 Member Posts: 31
Should I see any movement in the internal syphon gauge on my new Utica gas steam boiler?  Should that be measuring the pressure in the system?  The needle doesn't move at all


  • Gauge on zero?

    If this is the standard 0-30 psi gauge, and your boiler is so perfectly sized, that all the steam it makes is condensed, then you won't see anything on that gauge. That's why we recommend installing an additional 0-3 psi gauge which will show the ounces of pressure.

    Is the boiler cycling on pressure?--NBC
  • jp741
    jp741 Member Posts: 31

     To be honest, I'm not sure what "cycling on pressure" means.  We are having an issue with it short cycling.  running for 5 mins then off for one, on again for 15 mins then off for one then on again.
  • Pumpguy
    Pumpguy Member Posts: 630
    You might also consider....

    installing a compound gauge, one that shows 30" Hg. vacuum and 15 PSI pressure.  These compound gauges are also available with other  calibrations on the pressure side, although I have not seen any with a lower pressure calibration than 15 PSI. 

    Reason I'm offering this suggestion is, there is always a possibility that your boiler is at a vacuum rather than a positive pressure, but without a vacuum scale on your boiler gauge, you would never the pressure has gone below positive. 
    Dennis Pataki. Former Service Manager and Heating Pump Product Manager for Nash Engineering Company. Phone: 1-888 853 9963
    Website: www.nashjenningspumps.com

    The first step in solving any problem is TO IDENTIFY THE PROBLEM.
  • gauge choice

    I don't think the boiler is cycling as a result of a vacuum, so the 0-3 psi gauge would be best here.

    have you observed the boiler firing? you may be able to see any other reasons for short-cycling, such as an unsteady waterline.

    was the boiler ever skimmed after its installation?--NBC
  • steamedchicago
    steamedchicago Member Posts: 72
    boiler shutoff

    Boilers shut off for three main reasons:

    1) thermostat says it's warm.

    2) low water

    3) pressure target is reached -- this means you're making steam faster than its being condensed.

    1) isn't likely to be the cause, if it's coming on again.

    2) could be it. There are some low water cutoffs that automatically kill the flame to see if the water level is too low. Boiler could also be low, if too much water is being carried out of hte boiler with the steam.

    3) means your making steam faster than it condenses. Steam heating boilers are very low pressure, and should not be operating more than a couple psi. Higher pressure does nothing but cause problems and waster fuel, so there's a sensor that shuts the boiler off when the pressure reaches the set point (a 'pressuretrol' on most boilers), and then back on when it falls below the low setting. this is 'cycling on pressure' this could be bad main vents, or an oversized boiler, or something else.
  • jp741
    jp741 Member Posts: 31

    I believe the boiler was skimmed at installation,  when the service man came back he said since the sight glass looked clean it wasn't necessary to re skim...is that correct?
  • BobC
    BobC Member Posts: 5,473

    If there isn't any significant movement in the sight glass while steaming or any signs of an oily film in the sight glass the water is probably ok.

    That leaves with the pressuretrol shutting it down and allowing it to restart when the pressure falls. Modern pressuretrols don't go below a 1.5psi cutout and some 30psi gauges may not show that low a pressure. An auxiliary 3psi gauge would show you what is going on.

    How long are your steam mains and what size pipe are they? What make and model main vents do you have?

    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • HF
    HF Member Posts: 2

    i also had a new boiler installed recently and had a similar cycling problem. my cycling issue was resolved by changing new thermostat settings to steam and 1 cycle per hour. they usually come preset for forced air which is 6 cycles per hour.
This discussion has been closed.