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Intermittent ignition

Sure, any build-up is a ticket to problems because electricity has a heck of a time getting through "stuff" that's not metal.

Going into lockout depends uponthe model of the module. If it's 100% lockout, you get only one try, and if you fail to light you can't try again until you remove power from the circuit, e.g. turn the stat all the way down.

Other models of the module are non-lockout and will try indefinitely.

The newer S8610U, which can replace all of the older S86's, is "continuous retry," and can be used to replace the pain-in the tail 100% lockout. Continuous retry retries after a certain number of seconds, but non immediately. The pause between tries allows any accumulated gas to dissipate.


  • Jesse Markeveys
    Jesse Markeveys Member Posts: 9
    Intermittent Ignition

    I had a heat call today about a boiler that would go off somtimes but never consistantlly and when I went to check it out it was not doing anything except taking a little more time than seemed normal to light the pilot. So I pulled the whole assembly out and I saw a little bit of build up around the electrode. So I cleaned it off and then I put it all together. Then I ran it and the ignition was much sooner to light the pilot. I am not yet sure that I fixed the problem but I will give it a couple days and see if anything comes up. My question is would that build up around the electrode affect the flame rectification? Would that build up make it so that it would not proove? THen would the system go on lock out????
    Please someone respond!!!
  • Anthony Menafro
    Anthony Menafro Member Posts: 189

    If the system doesn't have a separate sensor wire coming back to the ignition module, you will not get a good reading through the combined spark/sensor wire causing lockout.

    Anthony Menafro
  • Jesse in addition to

    cleaning the sensor it is a good idea after to take a microamp reading. Are you familiar with how to do this? If not e-mail me and I will mail you for free a guide that will show you how to take the readings and what the expected microamps should be.

    A normal microamp reading on Honeywell, Robertshaw and White Rodgers controls is 2 to 10 microamps. Fenwal controls may be a little higher depending on the control module. A normal read is about 3 to 5 microamps.
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