Click here to Find a Contractor in your area.
In fairness to all, we don't discuss pricing on the Wall. Thanks for your cooperation.
Need to contact us? Visit

Roll out switch for a boiler without one?

LanceLance Member Posts: 1
After a recent Carbon Monoxide problem with my boiler which was solved by a very thorough cleaning, my plumber said "It was too bad this boiler does not have a "Roll-out" Switch, which could have shut down the boiler because of the Carbon Monoxide. I asked him to install one on my hydathrem. He said if a boiler does not have one, we can't just put one on it. I have always respected my plumber, but I think it may just be he does not know how to do it. Is this something that Should, Could be done? and if so, how could I (An electrician) do it? Thank you for your help


  • JohnNYJohnNY Member Posts: 33
    Just because you're an electrician:

    Just buy one with a mounting bracket of some kind and wire it anywhere in the burner circuit in series with the gas valve.
    Go to any boiler manufacturer's website and look at the I&O manual of a similar boiler to find an adequate location to mount it.

    To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"
  • mikemike Member Posts: 55

    shouldn't you want a spill switch to protect against CO? a rollout would be for over flame?
  • Steve PaulSteve Paul Member Posts: 83

    Are you sure you mean a rollout switch,(ROS) or a blocked vent switch (BVS)? The ROS is usually installed in the boiler vestibule outside of and above the burners. It shuts the gas valve down in the event of a flame rollout into the boiler cabinet. The BVS is installed on the draft hood and will shut down the boiler if the flue is blocked and over heats. Each switch is a great safety feature for detecting heat where it should not be. But I would be very reluctant to try a retro-fit on a boiler that was not engineered with these controls. You will most likely void all manufacturers warranties and god forbid anyone is injured by fire or CO, the liability issues you can raise are all on your head. Check with the manufacturer and find out if they have a retro fit for what you think you require. If they tell you to leave it alone, leave it alone.
  • LwalLwal Member Posts: 3

    Thank you for the info: I suppose I want to install a Roll-Out & Spill Switch on my system which I will do after I contact the manufacturer. Thank you all for the quick response and sound advixe.
  • Boiler GuyBoiler Guy Member Posts: 585

    Where was the spillage occuring? When was the boiler last serviced? (prior to this condition) Maybe, regular maintenance will alleviate any reoccurence. Adding a "safety device" might just lull you into a false sense of security, creating an even more dangerous situation. JMO
  • SteamheadSteamhead Member Posts: 11,373
    I asked Glenn Stanton (of Burnham) about this a couple years ago

    and he thought it was a good idea, especially if the boiler has or will be fitted with a stack damper. Don't know what HydroTherm would say though....

    To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"
    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.
  • LwalLwal Member Posts: 3
    Hydrotherm says......

    After speaking with the Hydrotherm Tech, I found that a Retro rollout & spill switch is available for this unit, which I also found out happens to be 30 Years Old. I told him about the other boilers with the same problem at the C.G. Station and he said" We never had such a problem", anyway....I doubt it they would admit such a problem anyway. Raising the baffles sounds great! I'm gonna have give that a try.
  • Robert O'ConnorRobert O'Connor Member Posts: 688

    If your boiler is having problems and is/was churning out CO the cleaning certainly helped but I would want to know why it did it in the first place. Installing TFE's (Thermo Fuse Elements) such as a spill a.k.a. (blocked flue) switch and a Roll out switch is a great retro-fit that I would strongly recommend. I would defy any manufacturer that says otherwise. Adding redundancy and preforming such in an approved manor could only help you if something happened at the site.

    There are only three ways this condition could have happened to your boiler and ALL need to be addressed.

    1. Incorrect Gas Pressure

    2. Blocked or Partially obstructed Chimney or Flue

    3. Insufficient Combustion Air

    Have someone familiar with such a retro-fit do it and be sure to check all of thee above, cause if you don't, It will happen again, but next time the occupants may not be so lucky. Lastly (as others have already mentioned) connect the switches in series with the burner circuit. Good Luck!

    Robert O'Connor/NJ.....P.S....GET A CO DETECTOR AND HOOK IT UP!!!!!!!!!!!!
  • DanDan Member Posts: 388

    A flame roll out switch or block vent switch will not detect CO and may not shut the boiler down when CO is produced. As Mr. Conner pointed out, lack of combustion air can cause CO. The flame rollout and spill switch will not shut down the boiler in this case.
    As others have stated PLEASE find out what cause this situation. Install the extra safety items after! Thanks,
This discussion has been closed.


It looks like you're new here. If you want to get involved, click one of these buttons!