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  1. rflook

    rflook New Member


    My rather old immersion boiler decided to give up the ghost the other day, notifying the household by tripping the switches at the fuse box. I guess it is the heating element as replacing the fuse did nowt. No problems I thought as we have a boiler which can do our hot water for us - right? Wrong.

    Turning on the hot water actually turns on the radiators across the house? So reading up a little bit it seems this could be down to the 3 port motorised valve. Thing is I havent got a :nono: clue how to use the thing (it has Auto and Man on it). So I decided to try a few hours in each position - which still gave me no hot water - bugger.

    So looking at the piping system I tried to figure out the maze of pipes in my airing cupboard, it is like a mensa challenge in there (or at least it is to me). I have taken a photo of the piping to the right of the immersion boiler where the 3 port valve is - to the left of the boiler is another pipe which has feed coming from the cold water tank.


    The two pipes which run against the wall are baking hot. As are the pipes coming out of the bottom and right of the 3 port valve. The pipe from the left of it is only lukewarm (would be grateful if someone could explain the purpose of the left pipe, not quite sure why it is there). At the bottom of the image is what I imagine to be the boiler return pipe (the one with the red stop tap on it). My neighbour who used to be a plumber says that hot water should flow from the boiler into the immersion tank providing hot water. Is this correct?

    Would be grateful if anyone could provide any guidance here before I go out and spend money on new components which I may not need.

    Thanks in advance
    Last edited by a moderator: Jan 9, 2017
  2. dancinplumba

    dancinplumba Trusted Plumber GSR

    Why not go out and pay someone to do the job ??
    • Like Like x 1
  3. rflook

    rflook New Member

    Mainly because I like to learn how to do things myself. I am quite a hands on person and enjoy attempting to fix things and expanding my knowledge. If I genuinely cannot fix it myself, which is always possible, then will be happy to pay for someone to do it. But I'd rather give it a shot myself first.
  4. king of pipes

    king of pipes Trusted Plumber GSR

    It's probably the syncro motor in the 3way valve head they are available as a spare and are £10 to £12 only attempt if you are electrically Competent direction will be supplied with the motor , the other option is change the whole 3 way valve head quite a simple job if you are competent with the wiring isolate the electric supply and remove the fuse , trace the wire from the 3 way head to the junction box cut the wire below the box , take a picture on your smart phone of the wiring , remove the old head and replace with the new one before fitting just turn the spindle on the valve with a pair of pliers to make sure it's free it will only move a little bit so dont force it ,fit the new head and swap the wires one by one 5 in total and replace lids as removed and that's it again I stress only attempt this if you are competent to do so it not as easy as you may think , I have attached a diagram of how the valve works hope this helps regards k

    Attached Files:

    • Like Like x 1
    Last edited: Jan 9, 2017
  5. rflook

    rflook New Member

    Thank you. Was wondering if it might be the valve and was mulling over getting a new one. No chance will I be playing around with the syncro motor directly though. Will replace the entire unit I think
  6. SteveWannadoGas

    SteveWannadoGas Member

    not everyone can afford it. We have just had the most expensive time of year. Some people would rather learn to sort problems in their own houses. I for one don`t like being outsmarted by my own pipework.
  7. Best

    Best Trusted Plumber

    True, but really often not cost effective to attempt repairs and source parts if you haven't much of an idea. The electrics is the most worrying part.
    • Like Like x 2
  8. Masood

    Masood Guest

    There is such a thing as false economy. Mess up the wiring and there's a chance of blowing something else. Some wiring centres are like spaghetti tangled up and twisted around so much you can barely trace a cable. Nor everyone follows the same conventions for core colours (or even uses the same cables - some use loads of 2- or 3-core, some use 4- and 5-core.

    Learning is best done on less complex systems then working up to rewiring components of a Y-plan IMO.
    • Like Like x 2
  9. rflook

    rflook New Member

    Just wanted to say thanks for all the contributions. New 3 port motorised valve fitted and it seems (touch wood) to be working well. The only question is that when I took the old one out, there were what seemed like 3 washers inside of the motorised valve (they were slightly silicone looking) that were almost totally perished. The installation instructions for the new component didnt mention anything about washers so I didnt bother buying any to put in. Hopefully that wasnt a bad move.
  10. Best

    Best Trusted Plumber

    Are you sure the "washers" weren't something else, - maybe paste?
  11. dancinplumba

    dancinplumba Trusted Plumber GSR

    Hahaha you shall see if they are meant to be there or not
    • Like Like x 1
  12. rflook

    rflook New Member

    Yikes, now you have made me paranoid :-/
  13. rflook

    rflook New Member

    They could have been - what ever it was had clearly been there for a looooong time. The question is, if it was paste, what was it for?
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