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Boiler pilot won't stay lit

debbygdebbyg Posts: 7Member
edited April 7 in Gas Heating
My Burnham boiler pilot will not stay lit, even after replacing the thermocouple twice, and the gas valve. The valve was replaced 3 weeks ago, and the pilot stayed lit until yesterday. The pilot went out again yesterday and the tech replaced thermocouple again, it stayed lit for about 20 min, and has gone out 3 more times in the last 8 hours. The tech noticed that the new valve seems to have a fault, as it will not switch to "off", only "on" or "pilot" but I don't think this is the cause of the pilot not staying lit. The gas valve will be replaced again, and the tech said he hopes this will solve the issue, but honestly I don't think the valve the issue. When the pilot is lite, the flame is blue and consistent. Everything I have researched leads to changing the thermocouple and gas valve, so I am really at a loss trying to solve this.


  • JUGHNEJUGHNE Posts: 5,681Member
    Did the pilot burner get cleaned? The gas for the pilot passes thru a very tiny orifice in the pilot burner. It has to be removed and taken apart for cleaning. The orifice is barely a pinhole.

    Did the tech check the in and out gas pressure at the boiler?
    There is usually an adjustment on the valve to adjust the pilot flame.

    If your gas utility company is having heavy load their delivery pressure can drop, or their outside regulator could be slow.

    Any other gas appliances?
  • FredFred Posts: 7,866Member
    Make sure only the tip of the thermocoupler is actually in the flame. Not more than 3/8" to 1/2" and is cherry red. Also make sure the end that screws into the gas valve is straight in , screwed in hand tight plus a quarter turn with a wrench. That end is magnetic and needs to make good contact but there is no gas on that fitting so don't over tighten.
  • GWGW Posts: 3,406Member
    When in doubt check the millivolts, or keep guessing.

    No on,offpilot??????? how did the pilot light without a button to push?
    Gary Wilson
    Wilson Services, Inc
    Northampton, MA
    [email protected]
  • lchmblchmb Posts: 2,929Member
    is there a junction block on the thermocouple going to another safety?
  • debbygdebbyg Posts: 7Member
    Thanks for the replies! Until the last month, I knew zero about boilers, but have been working to research what could be causing the issues, so that I can at least have general knowledge when I am addressing the tech. So thank you for your help and suggestions! I am just concerned that they will change the gas valve, and consider it repaired (again) and not find what the actual issue is, as two techs have stated with pilot light issues, the only two things causing it are the gas valve and thermocouple.

    I have read something about a possible draft in the chimney causing the pilot to not stay lit, but I have my doubts it is anything having to do with this, as I have never had an issue with this in 16+ years of living in this house.

    * I will definitely bring up your suggestions in question form to the tech when he returns to replace the gas valve* (the gas valve has the on/off/pilot, but will not turn to the off position)

    *I believe the burner was cleaned when the pilot initially had this problem, but it never hurts to ask. I do not know if the gas pressure was checked, or if this applies, but I can say that our other appliances (water heater, gas stove and dryer appear to be working well)

    *I know the millivolts were checked the first time the thermocouple was replaced and were within the "range".

    * I am not too sure if there is a junction block, that will be something I should address with the tech?

    *the placement of the thermocouple is something I can and will check

    Thanks again for your help! :)
  • GWGW Posts: 3,406Member
    Ahh I misread, I thought I read just on and off with no pilot position. Still seems odd, I thought all Gas Valves has a off position

    Pilots getting blown out isn't normal.
    Gary Wilson
    Wilson Services, Inc
    Northampton, MA
    [email protected]
  • FredFred Posts: 7,866Member
    It probably has an off position. Some of those gas valves seem to have a small offset that requires the knob to be lifted or slightly depressed to get it to turn to the off position. You would expect the tech to know that??
  • debbygdebbyg Posts: 7Member
    Yes, the new valve has an on/off/pilot position, but will not turn to the off position. You would think when he replaced it, that he would have checked that it worked, but unfortunately I doubt if that has any thing to do with the pilot not staying lite, just another added complication. : /
  • JUGHNEJUGHNE Posts: 5,681Member
    On some valves, the same way you have to manipulate or push down the knob or lever to light the pilot light, you have to do the same to shut off the valve entirely. But parts can be defective right out of the box.
    And don't forget that the pilot can be "turned up".
  • toddburwicktoddburwick Posts: 1Member
    DebbyG, did you ever figure out why the pilot didn't stay lit? I have the exact same problem with my Burnham boiler pilot. I've had the coupler replaced, and the gas valve replaced, and yet still the pilot goes out every few hours. I've had 2 contractors work on it, and neither one has any idea where to go from here. Any more information on how you resolved your would be so helpful.
  • Tim McElwainTim McElwain Posts: 4,237Member
    Has anyone bothered to do a combustion test. When you have replaced the thermocouple and the gas valve without checking any millivolts or doing a combustion test. You are just guessing and that costs money. You really need to get hold of a pro who knows what they are doing. How about some pictures of the boiler, vent etc so maybe we can see more of what you may be dealing with.
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