Posting a message to the forum will remove the above advertisement
  1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.
  2. Checkout our Plumbers Insurance area - heavily discounted Public Liability Insurance and Van Insurance specifically designed for plumbers.

Discuss Valiant eco etc pro pressure problem in the Central Heating Forum area at

  1. Colin omara

    Colin omara New Member

    hi, I’m hoping someone can give some advice. My boiler keeps giving a error message of f75. I have replaced the expansion tank and it has been repressurised but what happens is the boiler will work then the red light comes on with error message the only way the boiler comes on is to send more water into the system which makes the pressure higher, the boiler will then work and it goes off again so the boiler ends up with the pressure being too high and I guess it discharges water out of the pressure release I fill it up again too high so the boiler works and round we go again. Anyone got any ideas? The tank is pressurized as I have done this a couple of times just to make sure! Thanks everyone
  2. Riley

    Riley S. Mod Trusted Plumber GSR Top Contributor!!

    Firstly are you gas safe?? If not you should not be removing that cover as it forms a combustion seal protecting you and your family from anything nasty the boiler could throw out.
    F75 is a common fault on these but you are going to need a gas safe engineer to remedy it
    • Agree Agree x 1
  3. king of pipes

    king of pipes Trusted Plumber GSR

    As above not a expensive fix but you will need a GSI to carry out the work at worst £300 . Kop
    Last edited: Mar 16, 2019
  4. Colin omara

    Colin omara New Member

    Hi, no I wouldn’t know what to do, but it cost me a small fortune replacing the tank the engineer said that would be fine which it was for a couple of days. I now keep filling up the system making the pressure too high to make it work and want ideas of what it is before a end up paying another few hundred on something that might not work so am after a list of possibilities so I can go to an engineer to get quotes, don’t want to be ripped off, any ideas would be great!
  5. Riley

    Riley S. Mod Trusted Plumber GSR Top Contributor!!

    Just get three quotes mate. Or go with Vaillant fixed price repair. I’m afraid you won’t get any specifics here. Not being awkward just safe
    • Like Like x 1
  6. ShaunCorbs

    ShaunCorbs S. Mod Trusted Plumber GSR Top Contributor!!

    Very common issue and anyone who works with them will know the issue

    Fixed price repair from vaillant

    Or someone who works with them often
    • Agree Agree x 2
  7. rpm

    rpm Trusted Plumber

    Don`t buy the parts or do any work yourself then if it still doesn`t work after a repair you call the man back.
  8. Harvest Fields

    Harvest Fields S. Mod Trusted Plumber GSR Top Contributor!!

  9. Colin omara

    Colin omara New Member

    Yeah no worries, I got two quotes last time and after paying out it still has exactly the same problem, thought there might have been a specific solution, thanks anyway
  10. Riley

    Riley S. Mod Trusted Plumber GSR Top Contributor!!

    Well there is a specific solution as we say get someone Vaillant familiar
    • Agree Agree x 2
  11. Stu-B

    Stu-B Member

    It’s a straightforward/common fix for a GS man.
    • Agree Agree x 1
  12. Colin omara

    Colin omara New Member

    Didn’t like the last guy so will start again with different engineer thanks
    • Like Like x 2
  13. CBW1982

    CBW1982 GSR Top Contributor!!

    Depending on where you are, Certain engineers specialise in particular boilers. I recommend as above Vaillant fixed price or engineer familiar with Vaillant boilers.
  14. rpm

    rpm Trusted Plumber

    Why does it depend where you live, don`t Vaillant cover everywhere?
    • Agree Agree x 2
  15. Riley

    Riley S. Mod Trusted Plumber GSR Top Contributor!!

    I think what he means is if they don’t go Vaillant fixed price then certain areas of the country are popular for certain brands of boiler. I’m in a very Glow-worm area as an example
    • Agree Agree x 1
    • Informative Informative x 1
Similar Threads - Valiant pressure problem Forum Date
WB HEATSLAVE 18 25 losing pressure Central Heating Forum Thursday at 9:22 AM
Solution for low head pressure. Bathrooms, Showers and Wetrooms May 19, 2019