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

Boiler constantly fires - strange Y/S plan hybrid??

Discussion in 'Plumbing and Central Heating' started by bc13, 22 Apr 2015.

  1. bc13

    bc13

    Joined:
    22 Apr 2015
    Messages:
    5
    Thanks Received:
    0
    Location:
    Surrey
    Country:
    United Kingdom
    My boiler is firing whether the programmer is on or off. There is no stat in the house as far as I can see. The programmer has been replaced, didn't make any difference, the heating is still constantly on.

    Having looked at the controls there is a 3 port valve, which then leads into a 2 port valve on the HW side. The heating side of the 3 port Ts off, one way to downstairs but then one way to another 2 port valve on the pipe.

    Pretty confused as to what's going on. Sure it's a wiring fault but the electrician won't do anything until I figure out if it's Y plan or S plan, and to me it seems a strange combination of the two. No idea what the two 2 port valves are doing on the system, they seem redundant.

    Any help would be great pease!
     
  2. Sponsored Links
  3. TeaTime

    TeaTime

    Joined:
    21 Jan 2015
    Messages:
    362
    Thanks Received:
    47
    Location:
    Kent
    Country:
    United Kingdom
    Hopefully some of the more experienced guys on here can offer some better insight, but, for me it sounds like you have two extra 2 port valves on a Y-plan. Not sure why you would need them though if the three port is functioning correctly.

    Have you got a diagram of yourfull system?
     
  4. 45yearsagasman

    45yearsagasman

    Joined:
    14 Mar 2010
    Messages:
    6,094
    Thanks Received:
    1,093
    Location:
    Norfolk
    Country:
    United Kingdom
    More info required. Cylinder type, boiler make/model, maybe a photo of the valves etc in airing cupboard. It may well be one of the valves telling the boiler to fire.
     
  5. bc13

    bc13

    Joined:
    22 Apr 2015
    Messages:
    5
    Thanks Received:
    0
    Location:
    Surrey
    Country:
    United Kingdom
    The boiler is one of those little compact Pottertons, Envoy i think. Not sure on the cylinder.
     
  6. FiremanT

    FiremanT

    Joined:
    16 Jan 2012
    Messages:
    9,262
    Thanks Received:
    1,838
    Location:
    Uk
    Country:
    United Kingdom
    BC:Are you the householder, or a plumber? If the former, them the sparks, if he is being paid, ought to help identify. He should be able to identify what is switching what.

    Maybe it is a DIY install, the 3 port being operated by the programmer, the 2 port being operated by the cylinder stat. Can't imagine why, but then, I can't imagine why there is a 2 & a 3 port.

    The heating on all the time is probably a stuck on micro switch on 2 port.
     
  7. bc13

    bc13

    Joined:
    22 Apr 2015
    Messages:
    5
    Thanks Received:
    0
    Location:
    Surrey
    Country:
    United Kingdom
    Thanks Fireman, yes he should but I think he's in the dark as much as I am and has no idea what's going on.

    I don't know if it's a DIYer but the people in the house previously lived with the heating on for 2 years and just opened the windows as a solution instead of getting it fixed.
     
  8. Sponsored Links
  9. steve32

    steve32

    Joined:
    23 Nov 2008
    Messages:
    846
    Thanks Received:
    165
    Location:
    Essex
    Country:
    United Kingdom
    Is the hot water cylinder an unvented cylinder.
     
  10. bc13

    bc13

    Joined:
    22 Apr 2015
    Messages:
    5
    Thanks Received:
    0
    Location:
    Surrey
    Country:
    United Kingdom
    Nope. Conventional set up, only differneces are a recirculating HW pump and then the suspect port valves.
     
  11. 45yearsagasman

    45yearsagasman

    Joined:
    14 Mar 2010
    Messages:
    6,094
    Thanks Received:
    1,093
    Location:
    Norfolk
    Country:
    United Kingdom
    Not going to post photos? It would save a lot of guesses.
     
  12. bc13

    bc13

    Joined:
    22 Apr 2015
    Messages:
    5
    Thanks Received:
    0
    Location:
    Surrey
    Country:
    United Kingdom
    Can't i'm afraid, no longer at the house. Was just hoping someone had come across this before.
     
  13. ollski

    ollski

    Joined:
    8 Oct 2003
    Messages:
    7,090
    Thanks Received:
    543
    Location:
    Bristol
    Country:
    United Kingdom
    I'd imagine one of those zone valves has a sticky microswitch, dont need a sparky just a heating engineer with a multimeter.
     
  14. 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