Posted 15th Dec 2022
My boiler keeps randomly turning on and heating up the whole house on random parts of the day and night for around 30 minutes before going off again
It is a worcester 28i junior
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  1. Avatar
    A few things to check.

    Have you ever set up an automation via IFTTT (or similar service) to for example come on when a trigger is met, ie outside temp reaches 0°c? If so log in and delete it.

    Do your neighbours have the same wireless thermostat? If so they might be triggering your boiler.

    Frost protection is usually around 7°c, or at least ours is. Is the area where the room stat is located getting so cold that it's triggering the boiler?
    "Frost protection is usually around 7°c"
    If its only happening this week and stops Sunday you have your answer

    I've heard a few people recently with heating issues 6 are down at our local pool, a few at my work & some other people I know had to repair/defrost parts of their system (edited)
  2. Avatar
    Is it a combi boiler?
    My mum had the same problem with hers. The automatic diverter valve was faulty.
    When the boiler kicks in for the preheat (normal) the diverter valve was fully open so pumped round the system rather than just for hot water. (edited)
  3. Avatar
    My boiler does this sometimes when the batteries in the thermostat gets low. Either the boiler won’t shut off or it will fire up randomly!
  4. Avatar
    What controller are you using. If you have a budget range wireless one it is possible that a neighbour has the same set up and it is switching on your system. I had this issue with a solus controller a few years ago. You can change the frequency on it but also need to do the same on the main control unit. Anyway as you have already called Scottish Power and have them on contract let them figure it out for you. Good luck
  5. Avatar
    That's not good
  6. Avatar
    What is the minimum safety temperature set at. Sounds to me like it is getting to this safety low temp and firing up to protect the system.
    Is that the one on the thermostat
    If so that is set to 10 degrees
  7. Avatar
    As above. Where is your boiler located? I know of people having them in the garage and no radiator in there. The automatic frost setting kicks in and will continue until the garage reaches 7 degrees (in the meantime the house is boiling).
    It is in the kitchen with the radiator at the other side so can get fairly cold.
    I have boiler cover with scottish power is it worth getting them out to sort it?
  8. Avatar
    What is the temperature in the house? If you have a wall thermostat say in the hall - what is the temperature of the room it is in?
  9. Avatar
    The frost protection in the boiler shouldn't be heating all the rads in the house too, just the water in the boiler itself.…tml

    "It’s a misconception that this safety feature can significantly increase your heating bills. However, as the water that is heated won’t be circulated around your heating system or sent to the water tank for storage, you shouldn’t really see any change in the amount of energy the boiler is using. The boiler will only heat the water that is located within it, and the amount of energy it takes to do this is very minimal."
  10. Avatar
    Check what your thermostat is set to, if it’s a learning one it can do this, you need to switch it off doing that.
  11. Avatar
    You sure it's not the preheat setting?
    No it keeps coming on randomly through the day and night only when it is really cold outside
  12. Avatar
    Cheers for your help people, Scottish Power coming to have a look at it on Tuesday so hopefully find the cure
  13. Avatar
    Both me and my partner have Worcester Bosch boilers in our house fitted within the last 2 years. Both our boilers 'broke down' today. It was actually a blocked condensate pipe. I realised when I saw that the kitchen sink wasn't draining. The condensate pipe feeds into the kitchen waste water pipe, and this was frozen solid with water outside and into the house.
    The boiler was coming on for a short time (with gurgling sounds) and then cutting off.
    I bought a £15 heat gun from screwfix to thaw out the pipe.
    Same thing happened to me today for first time

    To the original poster, my boiler was doing this, but the radiators never got hot, just the pipe work around the boiler, was a pre heat function for water, turning eco mode on stopped it
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