Woecester 28cdi balanced flue boiler

[saltfleet]

I have a problem with CH preasure

I have checked the expansion cylinder valve and ait comes out.
I lowered the preasure which holds at 3 bar to zero pumped up the expansion cylinder untill preasure was 0.5 bar then refilled the system untill preasure reached 1 Bar.
After the CH had been running for 1/2 hr the preasure was back to 3 Bar

The preasure does not change from 3 Bar even when not in use overnight

Is the expansion cylinder OK
or is the problem with the water to water heat exchanger

Could some one help please

 

[kevplumb]

or is the problem with the water to water heat exchanger

is where i would be looking

you have removed the key and closed the valve of course

 

[bengasman]

Does the pressure go down after the system cools off?

 

[saltfleet]

Does the pressure go down after the system cools off?[/quote

no the preasure stops at 3 Bar when not used overnight or longer

thanks for reply

 

[saltfleet]

or is the problem with the water to water heat exchanger

is where i would be looking

you have removed the key and closed the valve of course

Yes I have removed the Key

 

[davebgas]

Drain the boiler, don't use CH and see if pressure goes up with key removed. If rises then plate heat ex is passing. To double prove repeat drain and don't use CH but isolate cold mains.

 

[saltfleet]

Drain the boiler, don't use CH and see if pressure goes up with key removed. If rises then plate heat ex is passing. To double prove repeat drain and don't use CH but isolate cold mains.[/quote

many thanks I will try this