Worcester 28cdi losing press

[tvrjohn]

Hi
Have had a search and good read here but cannot find the answer as yet

Please comment
Boiler been in for 10 years ok
currently gauge reads 0.2bar when heating is on it rises to 3bar
when heating is switched off it settles to the norm of 1.5bar, but after 2hours it returns back to 0.2bar.

Have topped up the system with the fill loop T bar, but it returns to the situation above.

Not noticed any PRV discharges

Whats the diagnosis please ?

Thankyou

 

[kevplumb]

check expansion vessel

how many rads on the system

 

[tvrjohn]

ok how do i check an exp vessel ?

 

[kevplumb]

//www.diynot.com/forums/viewtopic.php?t=175736

 

[tvrjohn]

Thanks Kev Plumb

 

[tvrjohn]

Hi Kevplumb or anyone else

Followed the link to FAQ
carried out the exp vessel repressurisation sequence

A small dribble of water came out of the air connector with little pressure behind it.

So i pumped up the vessel a bit and then released the air connector valve a bit more water came out with some pressure behind it, assumed this was now empty.

Pumped it up again, could not monitor the pressure as my gauge would not fit on unfortunately.
Then refilled the system via the loop till 1.5bar showed
Started CH and gradually over 20 mins the system gauge increased to 3.3bar, checked RV and it was just starting to weep at that pressure.
Switched off the CH and allowed it to cool, after an hour it returned to the 1.5bar mark.

Question, is the hot pressure rising high because the air pressure in the vessel is still to low ?
Is this result to be expected if i could not measure/control the vessel air pressure ?

Thanks for any comments, John

 

[kevplumb]

expansion vessel is screwed fella

 

[tvrjohn]

Hi KevPlumb

thanks for the prompt reply

screwed because there was water on the air side of the PV diapragm, meaning its split internally ?

Thankyou

 

[kevplumb]

yup right on the button fella

you can fit an external ex v tho