Vokera Mynute 16e room sealed boiler problem!

[Dan the plumber]

Good Morning one and all,

I am after a bit of advice regarding my parents Vokera boiler!

Yesterday, I bled an upstairs rad as it was only getting luke warm. There was a fair bit of air come out! Topped system back up to 1bar & everything worked fine.
Last night dad rang to say the boiler had stopped working!
Basically, this is the 2nd time in the same amount of mnths this has happend!
The boiler works fine but after the pressure has been topped back up & the boiler has been on for some time, the pressure builds to over 3 bar hence causing pressure relief to open & dump outside! The next time they come to use the boiler, the pressure is literally on 0bar hence boiler won't work!

Any suggestions? Do you think it could be that the expansion vessel needs repressurising!? Or a faulty pressure relief valve!?

P.s British Gas came out to this same prob around a month ago & engineer aparantly just took off filing loop & advised parents that a magna clean needed fitting!

Thanks in advance all.

Dan

 

[Deleted member 56158]

Pressure vessel has lost its air (1bar) or vessel pipe blocked. Easy fix, engineer could sort that in 30 mins. I do loads at this time of year.

 

[Dan the plumber]

Morning all,

Expansion vessel has been recharged to 1bar but above problem still happens!

Im not convinced the pressure relief is at fault as it doesn't do it's job unless pressure builds above 3bar!

Any ideas as to why pressure rises to almost 3.5bar when only approx 0.8bar of pressure is in the system from cold!? Do you think the expansion vessel may be shot hence no where for expansion to go other than outside!?

Why would bleeding 1 rad cause this problem!?

Thanks in advance for your help guys.

Dan