worcester greenstar pressure dropping

Discussion in 'Plumbers' Talk' started by Molliecollie, Mar 26, 2015.

  1. Molliecollie

    Molliecollie New Member

    Please, can someone on this forum help. The pressure on my gas boiler drops by 1bar daily, and I have to too up daily
    The condensing pipe which is a flexible tube coming from the bottom of the boiler, which goes into a waste pipe to outside has a constant drop, and sometimes a glut coming out of it. Is this why the pressure is dropping? I put a takeaway container on it last night, and it was full in a couple of hours. Any help appreciated, Joanne
     
  2. Joanne, if the condensate pipe drips and glugs whilst the boiler is running the central heating, then that could be normal as long as it ain't doing it excessively.

    If, however, it's dripping and glugging when the boiler is ofski and cold, then you have neatly diagnosed what is almost certainly the problem - a leaking exchanger inside your boiler.

    Bad news - it's expensive (many £100s...) but the good news is that W-B seemingly warrant them for 10 years.

    How old is your boiler?

    There's a spate of such reports on this forum - seems like W-B have got 'exchanger' issues...

    What I would suggest is going on to the W-B website and finding a local W-B approved GasSafe - unless you happen to know of one already (who do you use for your servicing?)

    When the guy comes out and hopefully confirms the fault as being the exchanger, then hopefully he will also say "Leave it to me - W-B will pay for the part and you'll only need to pay labour..." or something like that.

    If he says "Ooh, we're talking over £500 - time for a new boiler...", then ask him about W-B's warranty.

    If you are not happy with what you hear, please come back and report to us.

    Come back anyways and tell us what happens :).


    (The 'glugging' is down to a condensate trap inside the boiler - this works on a syphon principle so that it fills up to a point and then 'glugs' out to empty, then refills etc. so that bit is normal...)
     
  3. Dave does Gas

    Dave does Gas Screwfix Select

    From what you are describing that sounds like the normal function of a condensate pipe so before worring to much about your heat exchanger best to eliminate some other posssible causes first.
    Take a look out side there should be a copper pipe facing the wall just below the boiler position, Is there any water coming from this or any evidence of a leak? Try taping a plastic bag to it, leave fro 24 hours and have a look. If there is water in there its your PRV at fault, or operating as it should by letting excess pressure out.
    Does your pressure guage go very high when you have the boiler running? If yes thats your expansion vessel, which will either need to be re-charged, the inlet unblocked or worst case replaced.
    Are there any signs of a leak anywhewre in the property? Are your floors suspended wooden or concrete?
    Check all your radiator valves for a leak.
    Whist the heat exchanger problem is unique to the newer Worcesters it rare for them to fail give the amount of boilers produced to the amount that actually fail.
     
  4. KIAB

    KIAB Super Member

    WB exchanger' issues are well known, due to them being aluminium, they will try & wriggle out of the warrenty any way they can.

    Thank goodness my Valiant uses a stainless steel exchanger.
     
  5. Molliecollie

    Molliecollie New Member

    Thanks, the boiler is about 6 years old, the pressure gauge never goes into the red, and pipes are unfortunately embedded in concrete under floors so hard to look for a leak
     
  6. Molliecollie

    Molliecollie New Member

     
  7. Molliecollie

    Molliecollie New Member

     
  8. Molliecollie

    Molliecollie New Member

    Thanks for the reply, I had a WB engineer look at it last week and he put leak sealer into system, it seemed to work ok until now, it's only about 6 years old, I will turn it off to see if it still drips when off, if it does then is it the part you are talking about that I need?
     
  9. Almost certainly.

    If water comes out the condensate pipe when the boiler is cold and not being used, then that water can only be coming from inside the combustion chamber, and the only source in there is the exchanger (or associated fittings).

    (Ok, pedants might say that rain water coming in the flue could also end up there, but hey... :p)

    I'm guessing that the engineer who came out was not aware of this condensate pipe trickle?

    Call him out again and point out what you've noticed.

    If there's any argument about W-B paying for the part, then we'll sort them out a different way...

    But, from recent posts, it looks as tho' W-B will honour the repair chust fine. Not sure if they cover the labour charges, tho' - anyone on here know?
     
    Molliecollie likes this.
  10. G&W Plumbing & Heating

    G&W Plumbing & Heating Active Member

    If your pressure is dropping it is because your expansion vessel needs charging/replacing, PRV is letting by or you have a leak,
    Condense pipes drip it's there job but your sounds like it's leaking too
     
  11. Molliecollie

    Molliecollie New Member

    Thank you, I have put a container on it today while it's off to see if it still drips
     
  12. Joanne, is there another pipe outside the house nearby? A 15mm diameter copper pipe, probably also pointing downwards into a drain?

    If so, this'll be the safety discharge pipe that Dave and G&W are talking about - it is fed by a pressure release valve inside the boiler, and this opens if the pressure increases towards 3 bar as a safety measure. That's quite a common issue, but from what you were reporting my suspicion is still the exchanger in this case.

    But still worth placing a container under that pipe too!
     
  13. Molliecollie

    Molliecollie New Member

    Hi DA, I've just came home from work and the plastic container I have from the condensing tube was full, even though the boiler has been off all day
     
  14. Dave does Gas

    Dave does Gas Screwfix Select

    Bad news that, it does sound like a heat exchanger problem. Give Worcester a call for warranty call out to attend suspected leaking heat exchanger
     
    Molliecollie likes this.
  15. Molliecollie

    Molliecollie New Member

     
  16. Molliecollie

    Molliecollie New Member

    Thank you Dave, will do
     
  17. Molliecollie

    Molliecollie New Member

     
  18. Molliecollie

    Molliecollie New Member

    I've tried taping a bag to the small copper pipe, nothing is coming out or it, the condensate pipe has been dropping all day with boiler switched off
     
  19. Nice job, Joanne - that sounds pretty conclusive.

    I trust W-B will accept liability without argument, but if they try to be awkward at all, then they will need to be obliged to comply.

    Bottom line - there is no way that a heat exchanger should develop such a fault in 6 years - or even 10. Ain't made to satisfactory standards. There is no question at all that they can be made liable, and it will be a straight-forward process...

    So please come back and tell us what they have to say.

    Good luck :)
     
    Molliecollie likes this.

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