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boiler shuts down once a day

Josh M.
Josh M. Member Posts: 360
This may be a dumb answer or it could be just what you are looking for. Check the high limit on the boiler and also the differential. Are the pipes hot at all? Mabe you boiler just is just on the off cycle and waiting for the low limit to tell it to fire again. The pumps will work but the boiler won't fire until the water is down to a certain point.


  • CMS
    CMS Member Posts: 1
    boil shuts down once a day

    Installed a Raypack residential hot water boiler in my mothers house. Installed 6 zones of radiant heat. Once or twice a day the boiler will not fire up. The zones are still calling for heat and the pump is still pumping. Turning the power off and on causes the boiler to start back up. Any ideas what would cause the boiler not to fire, yet not shut the entire system down? An expansion tank with bleeder are installed on the return line.
  • jeff_25
    jeff_25 Member Posts: 110

    what kind of controls if gas it could be the spark control how are you reseting the unit
  • Does this boiler

    come equipped with a flow switch to prove flow through the boiler before firing it? Probably something similar to a FS-2 McDonnell Miller switch. That is where I would look first. Hope this helps.

    Glenn Stanton
  • Most residential Raypaks

    have a hot surface ignitor. What you are describing sounds like the HSI might not be providing adequate temperature to light main gas on every cycle. Call a Pro.

    Good luck.
  • hot_rod
    hot_rod Member Posts: 21,793
    Been a few years

    but some of those Raypaks have a control called an economaster, I think. It's a small printed circuit board looking device, under the hood. It's function is to run the circ pump for a few minutes, factory set at 5 or 7 I think, after the buner turns off. Often times those low mass boilers will overshoot the aquastat setting from residual heat and kick the high limit.

    Most had manual "red button" resetable type limits. But I have seen some with non resetable that would cool in a few seconds and let the burner fire again.

    Check to see if your model has the economaster, and make sure it is doing it's thing properly.

    Glens idea of a flow swuitch would be another good place to look. When the paddles start to wear they can fail to "prove on" Sometimes an on' off gives enough flow suddenly to "make' them.

    Remember lots of flow throuhg a copper tube boiler. Check the factory requirements on pump size.

    hot rod
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
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