Central heating losing pressure overnight when not in operation

Discussion in 'Plumbers' Talk' started by Richarda, Mar 3, 2018.

  1. Richarda

    Richarda New Member

    We have a Remeha boiler maintained by British Gas who do not maintain the pipe work and radiators.
    The boiler is about seven years old and has had a few faults over the years repaired by BG.
    The system works fine but will on intermittently lose its pressure overnight when the system is cold.The colder it is the more likely it happens
    BG says it must be our pipe work leaking but we can find no visible signs of water leak
    On Friday morning the pressure was nil
    We repressured to 1.3 but as soon as the system heated up the pressure rose to 4.2 which to me seams far to high but at least the boiler was working.
    The building is used as an office and I am sure the pressure will be nil again on Monday.
    Last night we let excessive water into the system in the hope there would be sufficient on Monday to fire up the boiler
    This always happens on the coldest nights of the year
    During this cold spell it is virtually impossible to find an engineer who is not rushed off his feet
    Any suggestions ?
     
  2. Hi Richarda.

    That's the classic symptom of a failed/discharged expansion vessel which is allowing the sealed system pressure to soar excessively when the boiler is on.

    Such systems are protected by a safety valve set to go off at 3 bar and release the excess water via a pipe to the ground outside. Have a look at the nearest outside wall to the boiler and see if there's a 15mm copper pipe either pointing close to the ground, or else bending back on itself and pointing at the wall. Almost certainly that's where the water is coming out.

    If you do find water coming out this pipe (you can always loosely tie a clear thin plastic bag over it to test, then that is a boiler issue and you are covered by BG's contract.

    DON'T over-pressurise your boiler to compensate. 1.3bar is good, but don;t refill to more than this. As the boiler heats, that pressure should not increase significantly, and over 2 bar should certainly ring alarm bells; 4.2 bar is positively scary...
     
  3. Richarda

    Richarda New Member

    Thanks
    I will investigate further on Monday
     
    Deleted member 33931 likes this.
  4. Tom86

    Tom86 Member

    DA said it. It's on 99.99% faulty expansion vessel. I'm very surprised what you've been told by BG. Amateurs... expensive amateurs tho :)
     
  5. Richarda

    Richarda New Member

     
  6. Richarda

    Richarda New Member

    Thankyou
     
  7. Richarda

    Richarda New Member

    Thankyou both for advice Just thought I would let you know how the problem was resolved.
    We returned to premises on Monday March 4 and the heating surprisingly had fired up at the preset time.
    Tied a polythene bag to the copper pipe outside as suggested but did not have time to do this until late Mon.afternoon.
    On Tuesday the bag collected about a pint of water and we repressurised the system on Tuesday afternoon .On Wednesday we collected a further pint during the day and I phoned British Gas to tell what the problem appeared to be and they sent the engineer back on Friday morning which I thought was quite quick for BG.
    He agreed the expansion vessel must be the problem and we signed his worksheet which also was supposed to authorise him to order a new expansion vessel.Our boiler mtce. agreement includes labour but not spares.

    Phoned BG the following Wednesday for an update and was told by someone called Joe that as we had not replied to their email on Monday, they assumed we did not want them to go ahead.Told him we had not received an email and we were not expecting one as we had already signed for the engineer to order the part.He told me the email was sent to Fred Clarke at our office and I said there were only 5 people here and no one called Fred Clarke.He said he would resend the message which still did not arrive so we phoned them back and this time spoke to a lady.It seems they had mis spelt our email address despite the fact that they had sent numerous emails in the last two months.We asked who Fred Clarke was and apparently this is a name engineers use if they do not know the name of the person they should address.I thought this amazing and even more so when the email finally arrived still addressed to Fred Clarke and stating they were sorry we did not wish to go ahead but quoting a price for the part.

    Phoned back and told them we did wish to go ahead and asked them why they thought otherwise.Were told it was in their standard format but if we confirmed by Email they would order the part.
    We did this quickly hoping to get some action.

    Phoned again the following Monday (this week) and asked for the progress and I was told the part was with the engineer and did we want to book a visit to have it fitted.I told them YES and eventually the engineer returned yesterday and fitted a new vessel.He said the old vessel was definately faulty and hopefully the problem is at last resolved.

    It was certainly a laborious process to get this fixed .
     
  8. Dr Bodgit

    Dr Bodgit Super Member

    BG...what a bunch of overpriced incompetent idiots.
     
  9. rogerk101

    rogerk101 Screwfix Select

    The most incompetent aspect of all of this is that the BG engineer didn't diagnose the problem on the symptoms you described in the first post. Even the amateurs among us figured that one out straight away.
    If it were me, I would not renew the contract with BG, and I would find a good local heating engineer who works on his own or with a team of fewer than 5 people. These guys get to know the systems they maintain, they know what they are talking about, and the staff churn rate is really low.
    I use a local heating engineer for the annual service, and could not be happier with their competence.
     
    Stan Lee Blade likes this.
  10. Richarda

    Richarda New Member

    Thanks .I think I will look for am independent company for a service contract.The problem round here is finding someone reliable who is not too busy to attend .
    The only good thing about BG is that they always turn up when there is a breakdown .
     

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