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Discuss Boiler wont ignite after power off in the Central Heating Forum area at

  1. gavc

    gavc New Member

    I replaced a couple of TRVs earlier, and prior to starting I powered off the boiler (a Main Heat 15). Boiler is 7 months old, and never been isolated from the mains before today.

    Once all the rads were bled, went to power on the boiler and now the pilot won't ignite. And the reset button doesn't do anything.

    As a total novice I'm not intending messing with anything, but does anyone have any suggestions?

  2. Brambles

    Brambles Active Member

    Do you have the same issue for Hot Water and Central Heating? Or is Hot Water only ok? If it is both not functioning:

    Is this operating on a sealed system?

    If so:

    Check that you have properly repressurised the system - it needs to at least 0.5bar

    Check that you have power to the boiler.

    Follow the reset procedure ( it is very simple) set out in the users manual - but you need to follow the precise process to ensure that the boiler has reset.

    If it is only not operating on heating:

    The motorised valve (s) would be my first point if call to find the fault.

    Thereafter, if no success you need a Gas Safe Engineer to look at it
    • Like Like x 2
  3. gavc

    gavc New Member

    Hot water seems OK, that seems to be the only the pipe that gets hot. Though I can't see the pilot light, so that's confused me..!

    Yeah, it's pressurised OK, I took it up to 1bar.
  4. Craig Watson

    Craig Watson Plumber GSR Top Contributor!!

    It doesn't have a pilot light.
  5. gmartine

    gmartine GSR

    No pilot on modern boilers fella.
  6. gavc

    gavc New Member

    Shows how much I know
  7. gavc

    gavc New Member

    Think maybe I surpassed myself managing to replace the TRVs without flooding the house! Need to call in the experts to get it up and running in that case..
  8. gmartine

    gmartine GSR

    The heating wont come on if the thermostat isn't set high enough.

    Set it on 25C and see if it fires up.
  9. gavc

    gavc New Member

    Did try, but I'll give that another shot..
  10. ShaunCorbs

    ShaunCorbs S. Mod Trusted Plumber GSR Top Contributor!!

    Is the pump running / can you hear it running
  11. gavc

    gavc New Member

    The pumps actually a lot noisier than before, and it's getting hot (the pump) after 5 or so minutes.. But the rads aren't..
  12. Craig Watson

    Craig Watson Plumber GSR Top Contributor!!

    Sounds like an airlock. Have you bled the pump or any airvents on the system? Have you bled the rads?
  13. gavc

    gavc New Member

    I bled all the rads. Didn't know I could bleed the pump tbh..? Or anything else.

    Now's when I wish I'd left it alone.. Obviously don't know enough about the system, and thought I'd be clever and replace the rad valves. :(

    So.. I just bled the pump. No air in that.
    Last edited: Jun 8, 2019
  14. Craig Watson

    Craig Watson Plumber GSR Top Contributor!!

    Got a pic of your pump and all associated pipework?
  15. gavc

    gavc New Member

    Just popped out for an hour will upload pic later. Cheers fellas.
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