Boiler Pressure Problems

[BrianCotsen]

Hello All

I have had an issue with my combi boiler for the last three years.

The problem

The water pressure is set at 1bar and this all stays absolutely steady throughout the year if I only use the combi for heating hot water for the taps/bath etc I can run the hot taps for 10 minutes or more and there isn't any change in the pressure.

If I put the central heating on I can only run it for about 3 minutes before the pressure rises to over 4bar and then I switch it off.

If it runs on then once the system cools down the pressure drops to 0 and I have to fill it up to 1 bar again.

Does anyone know why this might be happening.

The combi is about 5 years old and is an Ideal Response 80 .. I live in a 1 bed flat so I don't think the issue is over work.

Thanks in advance for any help

 

[sooey]

Your expansion vessel needs looking at, it may just need repressurising, but more likely it's knacked.