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May 2, 2020
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1
London
Member Type
DIY or Homeowner
Hello

Our Vaillant boiler has developed a fault in the last 2 weeks. The hot water is working without any problems. However, within 15-20 minutes of turning the heating on we are getting the error message 'F.75 Fault. Pump water shortage'. The boiler being on for heating is pushing the filling pressure above the max 3 bar it seems, which I assume is causing the shut down. To get it working again I push the reset button.

Do I just need to let some water out of a radiator?

For obvious reasons, I'd like to try to avoid calling someone in at the minute...

Thanks

JJ
 
What’s the pressure when the heating is off and it’s cold?
realistically you are going to need a gas safe engineer to repair but it should be a simple fix
 
Its an internal fault with the boiler, is it still under guarantee, either way its not something you can fix yourself.
Call a your engineer or Vaillant if its still under guarantee.
 
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Its an internal fault with the boiler, is it still under guarantee, either way its not something you can fix yourself.
Call a your engineer or Vaillant if its still under guarantee.
OK, thanks. It's not still under guarantee as far as I know. It's probably over 6 years old.
 
Heating a large volume of water makes it expand.
Not sure what it would cost in London sorry
 

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