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Vaillant boiler

dave_88
dave_88 Member Posts: 2
in THE MAIN WALL
make sure their is insulation tucked in above the flame roll out.

Comments

  • J. Reid
    J. Reid Member Posts: 9
    Vaillant boiler help

    Need some help. I am servicing a vaillant boiler and the boiler is natural draft 80 percent propane. The factory rollout switch is 240 deg. C - the switch opened I checked with a laser temp gun after unit ran for ten min. The switch itself was 1500 degree F - I checked heat exchanger not plugged, checked draft - good draft, gas pressure good, after half hour temp at limit dropped to 250 deg and ran fine. Any suggestions on why the initial high temp and what to do to correct it. Thanks.
  • Jerry_15
    Jerry_15 Member Posts: 379


    A infra-red heat gun is a wonderful tool, but I would never use it to check temp on pipe, or a roll-out. I think your temp specs at 240c, and 1,500f are a bit off. Sounds like you have a bad roll-out switch, replace it, they're cheap; especially check wiring connections more likely your problem.re-crimp everything, check continuity. The gas manifold pressure, not inlet pressure, on full burn is critical on LP. Good luck
  • J. Reid
    J. Reid Member Posts: 9


    CHECKED MANIFOLD PRESSURE IT IS AT 10 W.C. YOU ARE RIGHT ABOUT THE INFARED BEING INACCURATE ON PIPE BECAUSE IT IS REFLECTIVE SO I PUT IT RIGHT ON THE DULL CERAMIC ROLLOUT SWITH AND GOT THE HIGH TEMP I REPLACED THE ROLLOUT ALREADY ONLY LASTED A COUPLE HOURS. AS FOR THE INSULATION ABOVE THE SWITCH THERE IS NONE.
  • Jerry_15
    Jerry_15 Member Posts: 379


    Post-script The slip on connections expand with heat. Squeeze em a bit and make it tight, while you're re-crimping. This is a regular failure with many boilers.
  • Jerry_15
    Jerry_15 Member Posts: 379


    That insulation is a good trick for a Teledyne Laars. Not this kind of rig. With a ceramic fuse link I would start to think about the flue temps above and below the vent damper, heat gun is perf for this, maybe a cleaning is needed, for the flue, and maybe brush out on the burners and gen cleaning is not a bad idea, including the pilot assembly, gently, sometimes they get a carbon trail. Not sure about the manfac's requirements for manifold presure, but they always stamp it on there somewhere; and it is critical. Good luck
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