Whats wrong near my federal heat? I had to top up my combi boiler this morning to 1bar....

I had to top up my combi boiler this morning to 1bar. I put the inside heating on, and the pressure jump to 3.5 bar, and the overflow pipe starts dripping, to lower the pressure. Its presently on 2.5 bar, stabilised, stopped dripping, but I know tomorrow morning I will own to top it up again. Whats the matter?

I own bled the radiators this morning, but that didn't release any air.
Remove check tap on sump pump surrounded by...
Answers:    Yes,its the expansion vessel.when the indicator on the front of the boiler is at zero,locate the schreudder tap which is normally at the top/back rotten the boiler,pump the vessel up using a foot pump with a evaluate on it,roughly to 0.75bar.If the vessel wont hold a charge,then its burst and requirements replaced.A corgi engineer will requirement to do that job.You dont hold to take the shell off to pump up the vessel,so you can attemp this yourself.
A details to r m,to replace the expansion vessel you do have to be corgi registered,as you own to carry out a full gas safekeeping check once the job is done.I dont know where on earth you get your info from but it is wrong.
My innkeeper have be contacted + times on...
Sounds resembling you have a minor filter some were , save your eyes peeled for clammy patches.suitable luck