Baxi 105HE water pressure going too high

[dondaviduk]

Hi,
I have a Baxi 10HE boiler and since yesterday the pressure is shooting up to 2.5 bar when I turn on any hot water tap, until it eventually jumps to 3bar before tripping out the boiler [30C & 40C lights flash together].

the normal pressure when system is reset is 0.9 bar approx. I don't like to increase this in case I cause any further problems.

I have bled the radiators and the heating system seems to work ok.
Does anyone have any ideas to what the problem could be, or some things that I can check myself.
thanks in advance

 

[steve32]

Was the pressure in the expansion unit checked when it was last serviced
If not it needs checking have a look at the FAQs