Hot water pressure getting worse

Discussion in 'Plumbers' Talk' started by pledgeX, Jun 14, 2019.

  1. pledgeX

    pledgeX New Member

    The pressure on the hot water in our house feels like it's gradually getting worse. I'll try and take some measurements over the coming weeks/months to confirm, but I was wondering if anyone had any thoughts on what it might be, and anything that I can could try in the meantime.

    It's a combi boiler (Worcester bosch greenstar 25i from memory) Cold water pressure is absolutely fine. I think it's affecting all taps in the house, perhaps not the kitchen tap (but that's always had a lot better pressure than the rest of the house).
     
  2. terrymac

    terrymac Screwfix Select

    How old is the boiler and has it been regularly serviced ? Could be a simple blocked filter ,or if very old and neglected something worse. I assume you mean a lower flow rate ,as opposed to pressure.
     
  3. Mike83

    Mike83 Screwfix Select

    Are all isolation valves on the cold pipe to the boiler fully open including the one on the underside of the boiler?
    Definitely be looking at the filter in the water flow switch.
    If that’s ok then the plate heat exchanger.
     
  4. Wayners

    Wayners Screwfix Select

    Test taps... Run in a bucket and see how long it takes. Time... Try with hot water turned off but run the hot water tap so cold water comes out then do the same with hot water on. Is there a difference in time it takes to fill bucket?
     
  5. KIAB

    KIAB Super Member

    HW heat exchanger scaled up.
     
  6. pledgeX

    pledgeX New Member

    Yes.

    Not sure how to turn the hot water off without turning off the boiler entirely. But I tried it with the boiler turned off and it's the same time as with it on; 19 seconds to fill 1.2ltr pot. For reference it takes 9 seconds for the cold to fill up the same pot.
     
  7. Wayners

    Wayners Screwfix Select

    Can't be a hot water problem then.. More flow or pressure as the cold don't go through the boiler.. As for turning off hot water.. Should be a knob on boiler.. Heating and water... Just water and all off. Normally a pic of a tap and radiator
     
  8. gas monkey

    gas monkey Well-Known Member

    have a look at your tap washers if all taps same age may havve detereated
     
  9. pledgeX

    pledgeX New Member

    My boiler looks like this:
    [​IMG]
    In the central dial I set the hot water side to 'off', but I think all that does is turns off the feature to have a bit of hot water ready as soon as the tap comes on. With this set to 'off' the water still gets hot, but it just takes a few seconds to do so.

    The fact that it still performs the same with the boiler turned off, are you saying it can't be the heat exchanger or filter as others have suggested?

    It affects all taps but they vary in age from 2 years to 2 months so don't think it could be that.

    We did install a new bathroom a couple of months ago, but it was a like for like replacement and the only thing that changed was the taps and tails. Could something have happened during installation that could've caused this? Again it's affecting all taps in the house, not just the two new ones.
     
  10. The Teach

    The Teach Screwfix Select

    I would first ask the bathroom installers to comment,they have been tinkering with your plumbing :D
     
  11. pledgeX

    pledgeX New Member

    I was the bathroom installer... :(
     
  12. pledgeX

    pledgeX New Member

    Just a quick update in case anyone else has the same issue. It was indeed the heat exchanger.

    £250 for parts and labour.
     
    The Teach likes this.
  13. kiaora

    kiaora Guest

    Feedback is always good for all peoples !

    Sometimes using the correct words help, ie, my flow rate is poor, rather than my pressure ie poor .

    Good luck
    Regards
    Peter
     

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