Carbon monoxide from boiler

edited 30 November -1 at 1:00AM in LPG, Heating Oil, Solid & Other Fuels
5 replies 1.2K views
MrPlinkyMrPlinky Forumite
15 Posts
Hi there,

Often, in windy weather the carbon monoxide monitor near our bolier (which is in the kitchen) tends to either go off or flash a red light which I think means its detected carbon monoxide but not in sufficient quantities to alarm (?)

It doesn't happen all the time when its windy, but more often than not - so I assume its when the wind is going in a specific direction, although I could be wrong about this.

I normally open all the windows or switch off the heating when this happens.

Has anyone had this, or suggest what the problem is? Is is something to do with the boiler (which is over 14 years old), or something to do with the venting?

We are considering getting a new boiler when finances permit, but if there is a problem with the vent then this won't solve the problem...

Thanks for your help!


  • edited 25 February 2014 at 4:27PM
    alleycat`alleycat` Forumite
    1.8K Posts
    Part of the Furniture 1,000 Posts Combo Breaker
    edited 25 February 2014 at 4:27PM
    Had me worried as both mine do this from time to time so i just looked it up.

    Q: Why does the red light flash? Do I have CO?

    No. The red light flashes to show the CO Alarm is receiving battery power.

    One of mine has a digital reading on it which has never changed from zero, the other is a more basic design but is from the same "family" of alarms and they both on and off have a quick red "flash" then go back to green.

    If it's actually going off, i agree thats a concern but i don't think the red light is always going to be what you think it means.

    If you are really concerned about the boiler have someone recommended and trustworthy look at it.
    It might be something as simple as the way the wind is blowing that is the issue.
  • lemontartlemontart Forumite
    6K Posts
    I am responsible me, myself and I alone I am not the keeper others thoughts and words.
  • Get the boiler checked by an expert. The cost is cheap insurance when you consider the possibilities of a faulty unit. If you can't get someone immediately, I would invest in a second carbon monoxide detector to get a second opinion so to speak.
  • G_MG_M Forumite
    52K Posts
    Part of the Furniture 10,000 Posts Name Dropper Combo Breaker
    Check the instructions for the alarm: what does a red flashing light mean? What does 'go off' mean?

    In some cases it might be a low battery warning. Or it might indicate a low CO detection - sadly we can't see the instructions from here!

    It is possible that wind is blowing down the flue and causing a minimal amount of CO backdradt. As advised, get an OFTEC/GasSage engineer to check the boiler and the flue. A flue cowl or something similar might be needed.

    Or the boiler might be faulty.
  • consumers_revengeconsumers_revenge Forumite
    3.4K Posts
    Part of the Furniture 1,000 Posts Combo Breaker
    I read this and actually wondered if my wife had posted as this happened exactly to us.

    Sat down one night and the carb mon alarm went of. Never has in 2 years. Panic thought it was the smoke alarm. No smoke. Found it was the CO2 and as suggested on the back of unit do a reset and see if goes off again. 5 mins later it did. BG engineer out and boiler shut off at by him. Next day we had an engineer out and he tested found nothing wrong. The only explanation was freak wind in odd direction blew smoke straight back through an air vent and that's what set it off.

    Now not saying don't get it checked, you should...

    Also have a second digital meter placed elsewhere now.
This discussion has been closed.
Latest MSE News and Guides

Energy price cap could be extended beyond 2023

New plans have just been announced by the Government

MSE News

Cheap contents insurance for tenants

DON'T assume your landlord covers you

MSE Guides

Summer sizzlers round-up

Incl £2ish sun cream & £1.50 disposable BBQs

MSE Deals