WB 30CDi losing pressure daily but no air in system

Discussion in 'Plumbing and Central Heating' started by taz777, 25 Jul 2011.

  1. taz777

    taz777

    Joined:
    30 Jan 2011
    Messages:
    197
    Thanks Received:
    6
    Location:
    Middlesex
    Country:
    United Kingdom
    My WB 30CDi combi boiler is losing around 0.5 bar of pressure daily. However, when I bleed the rads, there is no air in the system. What could be causing this? I have the 5-year WB guarantee so i'm hoping it's simply a boiler-related issue and not related to the pipework or rads.
     
  2. Sponsored Links
  3. DP

    DP

    Joined:
    10 Dec 2003
    Messages:
    15,190
    Thanks Received:
    3,375
    Location:
    Glasgow
    Country:
    United Kingdom
    First of all, STOP bleeding the radiators. Each time you do that, you are introducing fresh water into the system which has air in it 20% of which is oxygen. This oxygen needs to eat, so it will be chomping on iron surfaces in your system

    ONLY bleed a radiator IF top rib is cold and base rib on the radiator is HOT

    The kind of leak you refer to, will show up as a wet patch or wetenss someplace. Check the pressure relief vent pipe for a start. Go look for the leak. Mind you, it could be inside the boiler as well in which case a RGI will need to attend
     
  4. ServiceNumpty

    ServiceNumpty

    Joined:
    9 Sep 2007
    Messages:
    6,962
    Thanks Received:
    1,697
    Location:
    Nottinghamshire
    Country:
    United Kingdom
    As dp says, check the pressure relief pipework, see if the end of it is wet/ damp.
    Secondly to save some time for the rgi and to rule out a leak within the boiler, isolate the central heating flow and return pipes from the isolating valves under the boiler, they are the extreme left, and extreme right hand side pipes. If there is still a pressure drop within 24 hours, then the issue is in the boiler, and time to call worcester out.
    If no pressure drop, then problem is on the radiator side.
     
  5. bengasman

    bengasman

    Joined:
    28 Jan 2005
    Messages:
    34,181
    Thanks Received:
    3,124
    Location:
    London
    Country:
    United Kingdom
    Pressure loss= leak.
     
  6. taz777

    taz777

    Joined:
    30 Jan 2011
    Messages:
    197
    Thanks Received:
    6
    Location:
    Middlesex
    Country:
    United Kingdom
    WB are coming out tomorrow. I'm hoping it's an issue with the boiler as the whole house has just been fully decorated. It would be awful to have to lift brand new flooring and carpets up!
     
  7. ServiceNumpty

    ServiceNumpty

    Joined:
    9 Sep 2007
    Messages:
    6,962
    Thanks Received:
    1,697
    Location:
    Nottinghamshire
    Country:
    United Kingdom
    If it's not an issue with the boiler, you may get charged.
     
  8. taz777

    taz777

    Joined:
    30 Jan 2011
    Messages:
    197
    Thanks Received:
    6
    Location:
    Middlesex
    Country:
    United Kingdom
    I'm not bothered about being charged. I see it as the boiler losing pressure. I just need the problem fixed.
     
  9. Sponsored Links
  10. looneyfitter

    looneyfitter

    Joined:
    29 Aug 2010
    Messages:
    552
    Thanks Received:
    51
    Location:
    Merseyside
    Country:
    United Kingdom
    My monies on the expansion vessel not being charged... Rubber lining perished= no expansion=blowoff running.
     
  11. taz777

    taz777

    Joined:
    30 Jan 2011
    Messages:
    197
    Thanks Received:
    6
    Location:
    Middlesex
    Country:
    United Kingdom
    The boiler, and the entire CH system is only around 3 months old. Could the expansion vessel lining have perished so quickly?
     
  12. looneyfitter

    looneyfitter

    Joined:
    29 Aug 2010
    Messages:
    552
    Thanks Received:
    51
    Location:
    Merseyside
    Country:
    United Kingdom
    Wont have perished but could be faulty. May not have been charged correctly or faulty shreider (spellling) valve. How big is the system? who fitted the boiler? ( vessel undersized maybe?)

    Anyways all the points of failure have been expressed.
     
  13. taz777

    taz777

    Joined:
    30 Jan 2011
    Messages:
    197
    Thanks Received:
    6
    Location:
    Middlesex
    Country:
    United Kingdom
    Oh well, it's the worst case scenario for me. The WB engineers was satisfied that the boiler wasn't leaking. The original CH installers are coming out next week to take a look - something i'm dreading as I have no confidence in their skills.
     
  14. Agile

    Agile

    Joined:
    26 Jun 2004
    Messages:
    64,039
    Thanks Received:
    4,595
    Location:
    London
    Country:
    United Kingdom
    We were telling you that it would not usually be a boiler manufacturer's fault although it could be an installer's error.

    Did the Worcester engineers charge you for their visit? They have every right to do so and most manufacturers will!

    Why do you have so little confidence in your installers? After all you chose them!

    If the pipework was the original, and particularly if it was previously open vented, then it could well be a leak in the original under floor pipework which is not, per se, the installer's fault.

    Tony Glazier
     
  15. taz777

    taz777

    Joined:
    30 Jan 2011
    Messages:
    197
    Thanks Received:
    6
    Location:
    Middlesex
    Country:
    United Kingdom
    No charge from the nice WB engineer. :)

    My original CH installers were the installers from hell. A verbal quote of £3K for a basic CH system in a 3-bed semi ended up costing me £7K.

    As for no confidence in original CH installers:

    No room/house sizing, no BTU calculations to size the rads, no Powerflush even though I was charged for this, five weeks of further visits at the end of the job to rectify other issues, couldn't diagnose blocked filters in newly-installed shower - costing me £1,100 to get a new water mains poly-pipe as they said it would fix the pressure issue. I then paid a proper plumber a further £120 to clean the filters in the new shower as the original CH company didn't flush the pipework.

    The workers would just step into my bath with their heavy work shoes and scratched it up badly. The pipework was all experimental and they eventually capped off a lot of their pipework when they couldn't reach under the kitchen cupboards properly. This cost me a further £500 to have a proper plumber reduce the pipework by eliminating all the redundant pipework.

    Each room had around 2-3m of trashed floorboards after they left.

    The boiler wasn't commissioned properly. And now the WB engineer has stated that my mains gas flow rate is below the minimum rate required for the WB 30CDi boiler.

    And finally I have a leak in the CH system - this is going to cost me £350 to fix.
     
  16. 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

     
Loading...

Share This Page