Baxi combi 105e

[Beau]

I have recently changed a leaking radiator valve due to low pressure now holding pressure when hot at 2bar. However, when the pre heat starts you can hear what appears to be air in the system when the pump runs, no leaks visible, but the bleed vale appears to worked although covered in lime scale. I have bleed the air from at the boiler several times but it keeps returning what is causing this fault is this a common problem?

Any advice or information would be welcomed.

Beau........

 

[baxpoti]

Lack of water treatment.

Fernox boiler silencer is very good, you also need to add an inhibitor if none present.

 

[Beau]

Water treatment present, when CH is on boiler is on, no air can be heard and the system runs. The air in the system can only be heard when the pre heat runs..

Beau..

 

[namsag]

there is a fault with instant expansion vessels where they struggle to get rid off the air baxi have changed them.
It should come out over time if your lucky

 

[Beau]

Is it not possible to bleed the air from the expansion vessel?

Beau

 

[namsag]

Nope ,you can try pressurising it up to nearly 3 to try and shift it.

then drop pressure afterwards

 

[Beau]

Could I close the flow and return, drain and refill the boiler slowly in an attempt to remove any air form the EV like a new installation?

Thanks
Beau