Boiler question that has British Gas foxed...trips RCD..

Discussion in 'Plumbers' Talk' started by swags999, Nov 8, 2019.

  1. swags999

    swags999 New Member

    Hi, I have a glow work CXI, issue started with the boiler losing pressure each time a cycle ended. was fine on HW only, then when we switch to heating also it started to lose the pressure...

    When it came to come back on, pressure was at zero... then it started to trip the RCD, and then it blew the fuse in the PCB.

    Engineer has so far, changed PCB, said there was as few leaks inside from seals, now fixed -worked ..then tripped the RCD.

    So changed the 3 way switch... worked ok for a few hours... then tripped the RCD...BUT still worked on just Hot Water...

    So came back again, decided it was the Flow valve - put in a new one...is working fine....BUT.. as they were here there new boiler guy came round and he tested the electrics by putting a Safe and See (I think it was called, test the earth) in a plug socket in the house, whenever he did this...it tripped the boiler RCD.

    Now Boiler is working right now..but I am not confident on for how long, and British Gas have basically washed thier hands of it saying they dont know what it is..

    Its a weird and wonderful one I know...but any thoughts on the potential issue please let me know!

    All help appreciated i dont think it needs a new boiler as it essentially works!


    Thanks
     
  2. terrymac

    terrymac Screwfix Select

    Get an electrician in to check out your electrical installation. If he / she gives the all clear then Its a boiler issue. Is the boiler brand new ,and supplied / installed by BGas ?
     
  3. swags999

    swags999 New Member

    Hi, Thanks for the reply, sorry should have said, boilers about 8-10 years old, I have lived here for 7 had an issues with expansion vessel previously but other than that nothing else...Boiler has a dedicated fuse on the main board, when I turned this off to isolate boiler and ran the earth test again, earth test was fine...
     
  4. terrymac

    terrymac Screwfix Select

    Your terminology is confusing.
    Is the circuit dedicated to the boiler only ?
    Is it protected by a fuse ,or MCB ,RCBO .
    Is it tripping a RCD ,or one of the above ?
     
  5. swags999

    swags999 New Member

    I am no expert, so apologies I am sure this terminology is wrong too but hopefully you can understand what I mean.

    It has its own fuse in the main fuse board. My fuse board is split into 2 half with separate trip switches and a master.

    Boiler has been tripping switch on the half of the fuse board the boiler fuse is in.
    (before BG replaced PCB it used to also blow internal fuse on boiler PCB - now does not do this, just fuse on board)

    With the boiler fuse switched off, the earth test did not trip the fuse board switch. (and its still on OK so far today..)
     
  6. terrymac

    terrymac Screwfix Select

    Post a pic of the consumer unit ( fuse board). And indicate what trips ,if anything ,at the moment.
    Don't know what " earth" test you are doing ,but if its one if those things that plug into a socket outlet ,its next to useless for identifying what your problem is .
     
  7. swags999

    swags999 New Member

    Thanks Terry,

    Right now, nothing is tripping- fingers crossed it remains that way

    So using image below which is basically my set up, it trips the RCD related to the half with the dedicated Circuit Breaker.

    I dont know what the guy was using, its was part of a new boiler quote, just odd that when he ran it, boiler tripped its RCD again... other wise running OK for now.

    But I think this means there is an issue unresolved with the boiler or its circuit and it might go off again..

    [​IMG]
     
  8. terrymac

    terrymac Screwfix Select

    I have read all your posts again ,and as far as I can make out ,the MCB that protects the boiler circuit has never tripped ,but the RCD has ,in the past ,and when there were identifiable faults ( which have since been cured, and all is working OK now).
    However ,at some point BG man plugged into a socket ( which has nothing to do with the boiler ,and is not on the same circuit ) some testing device or other ,and the RCD tripped when he did this.
    Is the above all correct ?
     
  9. swags999

    swags999 New Member

    I have read all your posts again ,and as far as I can make out ,the MCB that protects the boiler circuit has never tripped ,but the RCD has ,in the past ,and when there were identifiable faults ( which have since been cured, and all is working OK now).

    Correct since new flow valve this morning

    However ,at some point BG man plugged into a socket ( which has nothing to do with the boiler ,and is not on the same circuit ) some testing device or other ,and the RCD tripped when he did this.

    Correct also this morning, but with the circuit breaker to the boiler turned off, it didn't trip RCD...

    In fairness it seems to be working fine for now, but I have a nagging doubt there is an unresolved issue in the boiler circuit that is not fixed and will come back...

    And thanks for taking the time Terry to read and reply.
     
  10. terrymac

    terrymac Screwfix Select

    Your welcome.
    Hopefully you will not have any further issues ,however there would appear to be some earth leakage on the boiler / its circuit.
    See how things progress,time will tell !!
     
  11. swags999

    swags999 New Member

    I think you are right, but I would like to try to figure out what this is, what is an earth leakage? A short somewhere?
     
  12. Hans_25

    Hans_25 Screwfix Select

    An earth leakage is where the electrical current rather than going "in" 100% on the live and "out" 100% on the neutral is partially going out on the earth. The RCD measures the difference in current between live and neutral and trips if its more than 30 millamps.
     
  13. swags999

    swags999 New Member

    OK so it just tripped again.... worked fine on heating only for hours, then fine with HW also on for a couple more.

    Tested it going on and off on timer, when it came back on... was on a few minutes.. then trip..!
     
  14. The Teach

    The Teach Screwfix Select

    Quote = Boiler question that has British Gas foxed...trips RCD..

    if your paying the above named company,just ask them for a quotation for your repair. please post the recommendation from BG.

    hey its an easy fix !
     
  15. swags999

    swags999 New Member

    Teach, they have no idea whats causing it, hence the post.

    Having been here 4 times now, they came on a fixed repair jobbie and have reached 'their limit' having fixed more than one issue as they claim, though if you ask me the fact the boiler still has a fault means they have not fixed it and its not really my fault they keep changing parts... that dont seem to have fixed the issue to me!

    So they are not coming back...
     
  16. Dam0n

    Dam0n Screwfix Select

    Are you "insured" with them? If so then kick up a fuss and tell them the original problem is still there. Like you say it's not your fault they can't find the issue. They are happy enough to take your money each month so make them work for it for a change.
     
  17. swags999

    swags999 New Member

    No not insured, it was a fixed price quote... but if they wont fix it I am back to square one...
     
  18. Dam0n

    Dam0n Screwfix Select

    What did the fixed price quote say?

    Surely they can't take your money and not actually fix the issue?
     
  19. swags999

    swags999 New Member

    Well this is a point I am taking up with them to be sure, I have not paid anything yet...but even if I dont end up paying them..I still have a boiler that trips the RCD..
     
  20. terrymac

    terrymac Screwfix Select

    BG normally ask for your credit card details upfront , and payment is taken once the engineer has been and gone. Are you sure you haven't paid ?
     

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