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.

Steam boiler won't start (Weil McLain PEG50)

Vince1017
Vince1017 Member Posts: 7
edited November 2020 in Gas Heating
Please help with identifying the root cause of my heating problem

Weil McLain PEG50 (2017), Hunter thermostat. Just heat, no HVAC.

I disconnected thermostat for about a month due to construction. Today finally reconnected it but boiler wouldn't start after setting temp above room temp.

Troubleshooting steps/observations

1. Drained water/flushed water - LWCO won't lit.
2. Turned heat breaker off/on - single beep
3. Turned emergency power switch off/on - no luck
4. Electronic ignition pilot set to "On" position
5. Replaced batteries in thermostat
6. When pressing + or - button on thermostat - nothing happens/temp won't change.

Where should I be looking?

P.S. Also noticed "low battery" warning on t-stat even though put in brand new batteries. In 5 mins the message went away (not sure if it matters)

Comments

  • Jamie Hall
    Jamie Hall Member Posts: 23,170
    edited November 2020
    Without knowing which of about a dozen models of Hunter thermostat you have, it's a little hard to say -- but my first thought would be that the thermostat is damaged or not correctly connected. My second thought would be that something evil happened to the red and white wires (if your colour coding is standard -- it may not be). If you know what you are doing, you can try connecting the two thermostat leads at the boiler together -- the boiler should start. Do NOT connect those two leads to anything else, however. If you are unsure, don't.

    But based on what you describe, I'd bet on the thermostat.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • Vince1017
    Vince1017 Member Posts: 7
    edited November 2020

    Without knowing which of about a dozen models of Hunter thermostat you have, it's a little hard to say -- but my first thought would be that the thermostat is damaged or not correctly connected. My second thought would be that something evil happened to the red and white wires (if your colour coding is standard -- it may not be). If you know what you are doing, you can try connecting the two thermostat leads at the boiler together -- the boiler should start. Do NOT connect those two leads to anything else, however. If you are unsure, don't.

    But based on what you describe, I'd bet on the thermostat.

    Yeah, I did directly connect the leads - no luck. But LWCO being not lit with no water in unit still a separate issue, right?

    BTW, that's how the t-stat is wired (attached)
    583.jpg 245.2K
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,455
    Sounds like no power to the boiler
  • Vince1017
    Vince1017 Member Posts: 7

    Sounds like no power to the boiler

    How do I check? Is there a fuse or a reset button?
    JUGHNE
  • STEAM DOCTOR
    STEAM DOCTOR Member Posts: 1,954
    @Vince1017 While I am all in favor of homeowners do work within the scope of their abilities,  I think that you would be well served to call in a professional. Messing around with wiring can cause more problems then it solves. 
  • Vince1017
    Vince1017 Member Posts: 7
    edited November 2020
    Issue resolved. There was a second emergency switch I didn't know about (so silly!)
  • ethicalpaul
    ethicalpaul Member Posts: 5,695

    Sounds like no power to the boiler

    ^^^ called it!
    NJ Steam Homeowner. See my sight glass boiler videos: https://bit.ly/3sZW1el
  • Vince1017
    Vince1017 Member Posts: 7
    Sounds like no power to the boiler
    ^^^ called it!
    Yup