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

boiler losing pressure - no signs of a leak

Discussion in 'Plumbing and Central Heating' started by sunny12345, 27 Apr 2016.

  1. sunny12345

    sunny12345

    Joined:
    25 Jan 2009
    Messages:
    14
    Thanks Received:
    0
    Location:
    London
    Country:
    United Kingdom
    hi all
    my vailant boiler has been losing pressure at a steady rate (2 bar to empty in about 2-3 hours) for a few weeks now. i've had a boiler guy round and he said the boiler is fine, a plumber has been round and said there are no leaks at the rads, a leak detection guy round with his fancy toys but he wasnt able to find a leak. any ideas what else (if its not a leak) could be causing the pressure loss?
    There's no water damage anywhere on the ground floor ceiling, ground floor floor board have been lifted and none of the pipes are leaking. the only place we can physically see is in the kitchen behind the units where the pipes are in the concrete floor. the leak detection guy did check there but said there was no trace of a leak...... i'm approaching my wits end so any help/advice would be appreciated

    thanks in advance
     
  2. Gasguru

    Gasguru

    Joined:
    9 Sep 2005
    Messages:
    9,205
    Thanks Received:
    2,099
    Location:
    Sussex
    Country:
    United Kingdom
    What's the boiler make and model?

    How many times have you topped up the pressure over the last few weeks?

    Did the leak detection tech have all the gear..ie thermal imaging camera, tracer gases, sniffer etc?
     
  3. sunny12345

    sunny12345

    Joined:
    25 Jan 2009
    Messages:
    14
    Thanks Received:
    0
    Location:
    London
    Country:
    United Kingdom
    hi, we are having to top up the boiler ever couple of hours.
    yes the guy had the camera and the other bits
     
  4. sunny12345

    sunny12345

    Joined:
    25 Jan 2009
    Messages:
    14
    Thanks Received:
    0
    Location:
    London
    Country:
    United Kingdom
    vaillant turbomax 828
     
  5. Gasguru

    Gasguru

    Joined:
    9 Sep 2005
    Messages:
    9,205
    Thanks Received:
    2,099
    Location:
    Sussex
    Country:
    United Kingdom
    Check the safety valve pipework for a start...that's a significant leak.
     
  6. Tay7

    Tay7

    Joined:
    21 Nov 2015
    Messages:
    164
    Thanks Received:
    13
    Country:
    United Kingdom
    Are the copper pipes buried directly in concrete?

    Pipes direct in concrete ultimately fail.

    How old is the house and piping? This could be the culprit.
     
  7. Gasguru

    Gasguru

    Joined:
    9 Sep 2005
    Messages:
    9,205
    Thanks Received:
    2,099
    Location:
    Sussex
    Country:
    United Kingdom
    Is this really a Turbomax? or a Turbomax PLUS or Ecotec etc. Is it condensing?
     
  8. sunny12345

    sunny12345

    Joined:
    25 Jan 2009
    Messages:
    14
    Thanks Received:
    0
    Location:
    London
    Country:
    United Kingdom
    PRV is completely dry
    pipes are under the concrete for about 5m - from the boiler in the kitchen up to the front room where they come out under the boards.
    pipes have been in concrete for at least 20 years
     
  9. sunny12345

    sunny12345

    Joined:
    25 Jan 2009
    Messages:
    14
    Thanks Received:
    0
    Location:
    London
    Country:
    United Kingdom
    its a combi boiler.... i can check the exact model this evening
     
  10. Gasguru

    Gasguru

    Joined:
    9 Sep 2005
    Messages:
    9,205
    Thanks Received:
    2,099
    Location:
    Sussex
    Country:
    United Kingdom
    Need to know whether this is a condensing boiler....ie the leak could be going down the condensate pipe....on a Vaillant this is the plastic pipe on the RHS. To check the concrete the water should have been removed from the pipework and the tracer gas pumped in.
     
  11. sunny12345

    sunny12345

    Joined:
    25 Jan 2009
    Messages:
    14
    Thanks Received:
    0
    Location:
    London
    Country:
    United Kingdom
    RHS?
    yes, the water was drained and the tracer gas was pumped in but i was told there nothing was detected in the kitchen
     
  12. Gasguru

    Gasguru

    Joined:
    9 Sep 2005
    Messages:
    9,205
    Thanks Received:
    2,099
    Location:
    Sussex
    Country:
    United Kingdom
    Right hand side
     
  13. sunny12345

    sunny12345

    Joined:
    25 Jan 2009
    Messages:
    14
    Thanks Received:
    0
    Location:
    London
    Country:
    United Kingdom
    ahhhh duh lol..... no visible signs of a leak around the boiler. all pipes etc have been checked
     
  14. ianmcd

    ianmcd

    Joined:
    15 Aug 2010
    Messages:
    8,528
    Thanks Received:
    2,290
    Location:
    Lanarkshire
    Country:
    United Kingdom
    No what Gasguru is saying is that the primary water may be leaking into the condensate collector and running through the condensate pipe , this would not be visable you will have to disconnect the condensate pipe, (white plastic one) and with the boiler pressurised and turned off if there is water dripping or in your case a very fast drip as you have a significant leak , then you need a new heat exchanger.
     
  15. stardanny

    stardanny

    Joined:
    14 Nov 2007
    Messages:
    1,655
    Thanks Received:
    254
    Location:
    Buckinghamshire
    Country:
    United Kingdom
    Did the boiler guy do the check by turning off the flow and return isovalve under the boiler to rule out leak inside boiler?

    Daniel.
     
Loading...

Share This Page