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Thermostat control and Pressure control

Thermostat control and Pressure controlHow do i prevent the burner from coming back on once a heating cycle is starting.

If the temp has to move from 68 to 71 the boiler builds up steam then cuts off.  Then it will come back on in a few minutes because the desired temp is not reached.  How can I control this better so it does not keeping running on off so many times before it reaches the desired temp.




  • Tim McElwain
    Tim McElwain Member Posts: 4,506
    What are the

    settings on your pressuretrol? They should be no more than 2 pounds off to around .5 on.

    Is this a new steam boiler or an older one. New boilers make steam fast and have a higher steam velocity so cycling on pressuretrol is not unusual.

    Some pictures of your system may help.
  • Charlie from wmass
    Charlie from wmass Member Posts: 4,216

    The Tekmar 269 control gives outdoor temperature input and uses latent heat. [url=http://www.tekmarcontrols.com/prod/269.shtml]http://www.tekmarcontrols.com/prod/269.shtml 

    This may do what you want?

    I have never installed one but I am sure one of the guys who work on the big systems have used one.
    Cost is what you spend , value is what you get.

    cell # 413-841-6726
  • GBriggs
    GBriggs Member Posts: 15
    Steam Thermostat Cycle rate setting


    You must also look at the thermostat cycle rate setting. For simple control I would use a Honeywell TH5110D1006 and in the "installer set up" make the change to Heat only and set the cycle rate for steam. Please remember that out of the box it is set for warm air control. This is a +- 1 degree stat and you will not have the temp swing of 68 to 71 degrees which might keep you burner from running on the pressure controller.
  • Sly
    Sly Member Posts: 29

    i will upload some photos in a little bit.


  • Sly
    Sly Member Posts: 29
    Thermostat control and Pressure control pic

    Here are some pics of my system.  The lowered the pressure on the two cut in controls.  however someone who works on weil mclain boilers said to need to raise both back to 2.5.  This way the boiler goes to 5psi then cuts off when the pressure builds.  Let me know what you think.
  • Sly
    Sly Member Posts: 29
    Thermostat control and Pressure control

    Here are the pics again
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