Ekk!! My combi boiler reaches 4 bar in under 10 mins.....

[Wizzy]

Hi Guys,

I have a major problem with my Ariston A23 MFFI and it's scaring the bejesus outta me!
I have recently tried the CH, after only having the HW supplied throughout the summer, and the pressure rushes upto 4 Bar in a matter of 10/15 minutes! Naturally I turn it off at this point and it quickly returns to a safe level. I have recently fitted a new Airflow switch, as the old one was bunged up, and also have added an extra 1m flue extension due to a new conservatory.
My obvious question is what problems/faulty parts are associated with dangerous levels of pressure and how can this problem be cured?
So far I have checked each Rad by trying to bleed them but they were all fine and full.

Any help would be highly appreciated.

Thanks a lot.

 

[corgiman]

sounds like the expansion vessel has gone

CORGI job I am afraid as i think you have to remove the boiler from the wall to get to it

 

[Wizzy]

Thanks Corgiman - sounds like its time to call the professionals!
Cheers,

 

[cassis01]

Could you just add an exterior expansion vessel to the wall ? Would that make it easier

 

[keego]

As a temporary measure, drain off half the water in the nearest rad to the boiler, this will act as an expansion vessel. Not an ideal long term solution but it will get you by until you can get the expansion vessel changed.

 

[blahblah]

4 bar? Prv should have opened by then? So could be prv + exp vessel or a dodgy pressure guage. Any symptoms other than the guage?

 

[eireplumber]

the expansion vessel would have been my first thought as well but may be (as that cause im not firmiliar with the boiler) the pump has ceased? and its the water temp thats respnsible for the rise in temp? but as blahblah siad doesnt sound good that the prv didnt releave the excess pressure the should open @ 3bar. Needs to be serviced !!!!!!!!!!!