Biasi M96 expansion vessel

[Lucagt1]

From the research iv done I take it the M96 combi has an internal expansion vessel. Could anyone point me in the direction of where it is inside as I need to check it and or repressurise it.

My boiler makes too much pressure with the heating on (3 bar and up) then loses all pressure over night. From the many useful threads on this forum I'm currently at the conclusion that the expansion vessel is the most likely culprit. Does this sound correct?

Cheers
Jay

 

[muggles]

Yes,sounds very much like an expansion vessel issue. It's not inside, it's down the back

 

[Lucagt1]

Thanks for reply, wife has been in hospital so I kind of left it for the time being, but I'll take a look now and see if I can find it, had a boiler man look at it but he just wasn't listening to means decided to change a gas valve that did not fix the problem so I won't be having him back again.

 

[Lucagt1]

One other thing, would the expansion vessel be supplied with the boiler or would it have been purchased separately when the boiler was new?

 

[Agile]

Thanks for reply, wife has been in hospital so I kind of left it for the time being, but I'll take a look now and see if I can find it, had a boiler man look at it but he just wasn't listening to means decided to change a gas valve that did not fix the problem so I won't be having him back again.

I hope that you did not pay for a part which did not fix the problem.

The EXV is an integral part of the boiler.

To recharge with air, very carefully follow the instructions in the FAQ.

Tony

 

[Lucagt1]

Hi thanks Tony, no I have paid nothing as of yet which is the only positive I can take from the whole situation. I will certainly take a look at the faq and try to progress with this

 

[Lucagt1]

Ok found the faq and followed it through, no water came out on the expansion vessel but on the same score it was showing 3 psi on the pump. I have now drained, reset, and refilled the system, and although it took 3-4 try to fire up its now working for the time being. I will keep an eye on the pressure over the next day or so to see if it is still dropping.

I have spoken to the guy who came to look at the boiler and believe the part he changed was also necessary as it was the water pressure valve and he said it was leaking. why he didn't check the EV I will never know.

Lastly what is the general rule for how much pressure the boiler should make with the heating on?

Thanks to anyone that has helped this far.

 

[Agile]

Usually a system at 1.5 bar cold will increase by about 0.3 bar when fully hot.

Tony

 

[Lucagt1]

Great thanks, I also found a small water leak from some kind of temperature switch which I fixed and now seem to have stable pressure that does not leak down over night. holds 1 bar when turned off has done for 2-3 days now. runs at 1.8 bar with ch on.