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Problem with Weil-Mclain boiler

CamRCamR Posts: 15Member
My WM boiler is acting up. Have had no heat for the last 2 days. I have it shut off for now. When I turn it on, the power light comes on, then the TSTAT/Circ light, and then that's it. I'm thinking the control module is bad because no lights flash to tell me there's any kind of error or bad sensor, and the flame light doesn't flash after the allotted 15 seconds to detect flame from the pilot. BUT - could the electric pilot ignitor be bad? It's a CG model, and control module is 11365-605

Comments

  • Tom_133Tom_133 Posts: 613Member
    CamR,

    Dont just swap that control (though it could be the problem), make sure your igniter works, and your air switch is working. You can ohm out your igniter for continuity and check voltage on the air switch. Then if those both pass, you can think about the board.
    Tom
    Montpelier Vt
  • SteamheadSteamhead Posts: 12,868Member
    edited March 25
    What model series W-M CG? Does the ignitor light up as the control goes thru the trial for ignition?
    All Steamed Up, Inc.
    "Reducing our country's energy consumption, one system at a time"
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Baltimore, MD (USA) and consulting anywhere.
    https://heatinghelp.com/find-a-contractor/detail/all-steamed-up-inc
  • Tim McElwainTim McElwain Posts: 4,225Member
    Do you perhaps have a picture of the Integrated Boiler Control? It will help me to look up the troubleshooting for that control.
  • CamRCamR Posts: 15Member
    Steam head, the ignitor doesn't light up. After the boiler is turned on, about 5 seconds later the circulator kicks on, and then from there nothing else happens to it. Tim, the control module is a UT 11365-605
  • CamRCamR Posts: 15Member
    It was working, working, working, then it just wasn't. No failure lights, no smoke or gas smell, the heat just stopped.
  • SteamheadSteamhead Posts: 12,868Member
    @Tim McElwain will confirm this, but I believe on most of those units the igniter runs on 120 volts. If there is voltage at the igniter plug but it doesn't light up, the igniter is bad.
    All Steamed Up, Inc.
    "Reducing our country's energy consumption, one system at a time"
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Baltimore, MD (USA) and consulting anywhere.
    https://heatinghelp.com/find-a-contractor/detail/all-steamed-up-inc
  • Tim McElwainTim McElwain Posts: 4,225Member
    Does this unit have a Spark Ignited Pilot or is it a Hot Surface Igniter? Which version of CG is it an "a" (CGa) version?
  • CamRCamR Posts: 15Member
    I believe Spark ignited, but I'm not sure. The gas flows into this metal thing with a knob you can turn off or on, then down to the tubes on the bottom of the boiler. Yes it's a CGa Gold
  • CamRCamR Posts: 15Member
  • JUGHNEJUGHNE Posts: 5,569Member
    Can you post a good shot of the wiring diagram, it may be on the back side of the doors.
  • Tim McElwainTim McElwain Posts: 4,225Member
    From the picture of the boiler it is a spark ignited pilot system. When you call for heat do you here it sparking at all? Do you have a multi meter? If so at the Honeywell gas valve see if you have 24 volts to PV to PV/MV. If no spark and no 24 to the gas valve do you have 120 volt power to the United Technology integrated Control 1135-605? If so is there 24 volts coming from the Integrated Control. If not then replace that control.
  • CamRCamR Posts: 15Member
    When it calls for heat there is no spark at all
  • CamRCamR Posts: 15Member
    Unfortunately do not have a voltmeter, have purchased the pilot ignitor/thermocouple (comes as an assembly, will replace those, also bought the control module. I will replace the PI/TC assembly first, see if that fixes it. If not, then I'll assume it's a bad control module and will replace the module
  • Tim McElwainTim McElwain Posts: 4,225Member
    Really not the way to properly troubleshoot and diagnose you may be throwing away money. I would suggest you spend some and hire a professional to take a look at your system. By the way your system does not have a thermocouple so you may have the wrong assembly. What are the numbers on the pilot it is usually stamped in the metal?
  • CamRCamR Posts: 15Member
    Well it has this steel tube that comes off the gas valve and goes under the burner tubes and goes next to the pilot ignitor, guess maybe it's not a thermocouple, but not sure then what it is
  • CamRCamR Posts: 15Member
    edited March 26
    This is what I'm talking about
  • CamRCamR Posts: 15Member
    That matches what's on my system
  • HVACNUTHVACNUT Posts: 2,030Member
    Yes that's the spark ignitor and flame sensor.
    If the existing assembly and wires look clean and intact. All molex connectors fully seated. Good ground.
    But like you said, there were no dummy lights at all, for flame loss or any other code.
  • JUGHNEJUGHNE Posts: 5,569Member
    Before the module will spark, it must see that there are no open limits and that the vent damper is open. Any one of these simple devices could keep the ignitor from sparking and pilot gas flowing.
    Your wiring diagram would show us what limits there are....some might even be resettable with the push of a button.
  • Tim McElwainTim McElwain Posts: 4,225Member
    The diagram will not do you much good unless you have a meter so otherwise we are just guessing.
  • JUGHNEJUGHNE Posts: 5,569Member
    After you cir pump turns does your vent damper open?
    That must happen before firing.
    You can read the sequence in the manual that Tim has posted above.
    One of the limits has a small red reset button.

    If you are not sure of any of this happening you can change your parts, maybe work or not.
    Then call a pro for help.
  • CamRCamR Posts: 15Member
    Sorry, Jughne, nothing on my system has a reset button. At least not one I can see anywhere. Vent damper does not open. Lighting sequence suggests it has to have power, then turn on circulator/get call for heat from thermostat, then limit light has to come on, then damper opens, then flame. Also, I just noticed my Vent damper has been in the "hold open" position at least since we moved in just over a year ago. Boiler was installed 10-10-2013
  • CamRCamR Posts: 15Member
    Here's the wiring diagram. And nevermind, found that reset button
  • CamRCamR Posts: 15Member
    Finally got boiler to work, after hitting that reset, heard an odd noise, then got flashing flame light. Now we're making progress!
  • CamRCamR Posts: 15Member
    Haha so that weird noise was because I forgot to reopen the gas valve. Opened the valve, turned boiler on and it's working! Do I still need to replace anything?
  • HVACNUTHVACNUT Posts: 2,030Member
    edited March 27
    Well, that button you pushed was to reset the spill switch.
    If it happens again you'll need a pro to go over the whole system including the chimney.
    The spill switch is a safety device that basically prevents the boiler from firing if it reaches the spill switch max temperature.
    The flue gases are not escaping out the chimney, but coming back through the draft hood. That means carbon monoxide.
    I could have been a downdraft or other obscure situation but to repeat, if it happens again, it must be checked. It could be a life threatening situation.
    Do you have a low level carbon monoxide detector?
    The damper can be left open but you'll lose a few % in efficiency.
  • JUGHNEJUGHNE Posts: 5,569Member
    That could be why the vent damper was in the lock open position. The chimney draft could be marginal. By leaving the damper open there is some draft established by the basement warm air flowing upward.

    You should have a good CO detector or 2 near the boiler.

    You might be able to return the new parts if they are still sealed as they come off the shelf.

    You should download and print the manual.
    This will give you some idea of future issues.
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