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Vaillant Combi pressure loss.

Discussion in 'Plumbing and Central Heating' started by whistler, 13 May 2019.

  1. whistler

    whistler

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    Boiler is a Vaillant combi turbomax 824. Over last couple of weeks has been losing water pressure requiring a top up every few days. Have checked all radiators, taps and visible pipework, but no sign of any leaks. However most of the pipework is below floorboards so cant be checked.

    Is it likely to be anything in the boiler? I'm thinking expansion vessel. Before I call in the heating engineer, anything I can check to identify whether it's the boiler or pipework?
     
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  3. Gasguru

    Gasguru

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    Check the safety valve pipe outside...
     
  4. ianmcd

    ianmcd

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    you will have an outlet pipe from the Pressure releif valve , it should be outside , tie a ballon or freezer bag or the likes over this outlet and see if it collects any water
     
  5. whistler

    whistler

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    I set the pressure to about 1.5 bar and fired up the boiler and it quickly rose towards 3 bar so I'm guessing its the expansion vessel?
     
  6. ianmcd

    ianmcd

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    well you are guessing rightly
     
  7. whistler

    whistler

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    Followed the procedure to re pressurise the ev and tried again but the pressure still rose to 3. So looks i need to get the engineer in to fit a new ev. Just curious, as the ev is behind the boiler, does this mean a removal of the boiler off the wall? If so, I guess it is a expensive job. I have been thinking about a new boiler later this year, but if it has to come off the wall, maybe I should get it replaced now.
     
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  9. ianmcd

    ianmcd

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    because you never drained the boiler and left the drain point open when re-pressurising the boiler, if you dont follow all the steps there is no point in starting
     
  10. whistler

    whistler

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    ???? How did you work out what I did and didn't do? I said I followed the procedure which commenced with draining the boiler.

    I'm now thinking an external low cost expansion vessel may be my best option until I get a new boiler installed.
     
  11. That is his MO.....Jumping to ridiculous conclusions out of thin air.
     
  12. ianmcd

    ianmcd

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    Because if you had followed the procedure correctly, you would not have been able to pressurise the vessel if it needs replacing
     
  13. ianmcd

    ianmcd

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    Keep reading dipshoite you might learn something
     
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