1. Visiting from the US? Why not try DIYnot.US instead? Click here to continue to DIYnot.US.
    Dismiss Notice

Pressure dropping Glowworm 30 sxi

Discussion in 'Plumbing and Central Heating' started by b0ne5ish, 8 Oct 2018.

  1. b0ne5ish

    b0ne5ish

    Joined:
    19 Feb 2007
    Messages:
    10
    Thanks Received:
    0
    Country:
    United Kingdom
    Hi,

    I have a Glowworm 30 sxi boiler, a few days ago the heating wouldn't fire up, the pressure had dropped to 0.6 and was flashing on the screen. I topped up the pressure using the filling loop and the heating came back on. Next day same problem, the pressure had again dropped to 0.6 and after filling it up via the loop it started working again until the next day same problem etc...

    I've checked under the boiler itself, I can't see any leaks, there are no obvious leaks around the radiators or in the house. The boiler pressure relief pipe outside is dripping, it's worse after the pressure is topped back up, I top it up to about 2.0 bar.

    From what I've read on the net it could be the pressure relief valve that needs replacing, does this sound about right? Is there anything else it might be? Is it a DIY job to drain the system, replace the valve and fill it back up again or should I be seeking a professional?

    Thanks.
     
  2. Sponsored Links
  3. terryplumb

    terryplumb

    Joined:
    8 May 2017
    Messages:
    5,970
    Thanks Received:
    1,231
    Country:
    United Kingdom
    You should only get water from the prv pipe if the pressure gets around 3 bar. When topping pressure up ,do it when cold ,and just above 1 bar. Dont take it upto 2 bar ,its too high. Monitor the pressure after c/ heating has been on for an hour ,if its gone up to more than 2.5 bar your expansion vessel is not performing as it should ,much higher and the prv will operate. Once ch cools down ,say overnight after its turned off, water contracts / pressure drops. You wake upto no heating and the cycle starts all over again. Sometimes after prv has been opened ,they dont re seat or seal properly anymore and may need replacing ,but first you need to sort out the pressure drop / re filling issue.
     
  4. b0ne5ish

    b0ne5ish

    Joined:
    19 Feb 2007
    Messages:
    10
    Thanks Received:
    0
    Country:
    United Kingdom
    Thing is the pipe is leaking even if the central heating hasn't been on, I topped it up this morning to 2 bar and the heating's not been on all day and it's now at 1 bar and still dripping cold water out the pipe. I'll switch it on for an hour like you said and see how high the pressure goes.
     
  5. terryplumb

    terryplumb

    Joined:
    8 May 2017
    Messages:
    5,970
    Thanks Received:
    1,231
    Country:
    United Kingdom
    As i said earlier ,once prv has operated they some times no longer close fully. Allowing water to dribble out ,boiler off or on.
     
  6. b0ne5ish

    b0ne5ish

    Joined:
    19 Feb 2007
    Messages:
    10
    Thanks Received:
    0
    Country:
    United Kingdom
    OK thanks, if I top up to 1 bar when it's cold and leave the heating on for an hour what should I expect the pressure to rise to?
     
  7. terryplumb

    terryplumb

    Joined:
    8 May 2017
    Messages:
    5,970
    Thanks Received:
    1,231
    Country:
    United Kingdom
    If all is well with the EV , not much . Unless you have a very big house / lots of radiators ,should stay well less than ,2 bar.
     
  8. DIYnot Local

    DIYnot Local

    Joined:
    3 Sep 2019
    Country:
    United Kingdom

    If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

    Select the supplier or trade you require, enter your location to begin your search.


    Are you a trade or supplier? You can create your listing free at DIYnot Local

     
  9. Sponsored Links
Loading...

Share This Page