Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Intermittent problems igniting boiler

chriscokid Member Posts: 1

I have a Vitogas 100 GS1 with a Honeywell S8600B1009 electronic ignition. The system is about 6 years old. It is used for heating and DHW.

99% of the time it works fine, but once in a while it fails to ignite and goes into lockout. If I power down the boiler and power back up, it starts up fine.

This has been happening for a couple of years but less than once a month. I have completely cleaned the boiler and pilot/igniter/sensor at the start of this heating season hoping this would help but the problem started again. It seems to only happen when it is cold outside (less than 30f), it ran fine all summer for DHW.

Does anyone have any idea as to what could be the cause of this?



  • JStar
    JStar Member Posts: 2,752

    I'd verify spark gap, and good grounding. If it only happens when the weather drops, I'd check for proper draft conditions in the chimney and through the boiler.
  • furnacefigher15
    furnacefigher15 Member Posts: 514
    Only in the cold.

    My first step would be to look at the gas supply.

    I see many gas regulators in my area that feeze up after a rain then freeze cycle. The freeze typically happens at night.

    In your case the scenario might be overnight freeze of the regulator causing a lack of gas flow and a subsequent lockout. But by the time you notice there is/was a problem it may be morning, and by the time you get to look at the boiler the sun came out and the radiant heat from the sun thawed the regulator just enough to allow for normal operations when you hit the reset.
This discussion has been closed.