Replacing broken internal expansion vessel on a worcestor 24 cdi boiler

[thecalvers]

Fitting an external expansion vessel to my central heating pipework seems straightforward but I don't know what 'tidying up' :hammer: will need doing with the vessel in the boiler

does the vessel inside the boiler need decommissioning or adjusting somehow?

Thank you for your input.

thecalvers

 

[mylesy]

no just leave it mate. as long as the new one is working then the old one can just be left in.

 

[zzzjim]

A plastic cap on schrader may not go a miss , if its missing.
in case it drips !

( By some one GSR , next time its serviced ! )

 

[SimonJohns]

Agree with dust cap. Sometimes a schrader can pass when diaphragm is perished.

A pea sized amount of jet blue in schrader and cap on. Label to say u/s but still connected

 

[thecalvers]

Agree with dust cap. Sometimes a schrader can pass when diaphragm is perished.

A pea sized amount of jet blue in schrader and cap on. Label to say u/s but still connected

Thanks, that's very helpful. I'll just fit a dust cap, label the EV and fit one externally. I assume that fitting one the same size as the internal one is the said thing to do.. if I add a rad to the system will the expansion vessel have to be changed again? Should I upsize to a bigger EV just in case I hae extra rads fitted?

Thanks guys,

thecalvers.

 

[zzzjim]

More is best , manuf often under size original to save pennies which is why they die !

Long pipe runs soon mess up what is normal .

 

[Simon F]

the new expansion vessel will come with a pre-set charge that is probably higher than you will require.
check your boiler installation manual for the required vessel charge pressure ( likely .7 bar )
check this before fitting/pressurising the system

 

[mylesy]

you can buy a electronic pressure gauge from screw fix for around £7. they are very handy piece of kit. the best balance is to have the expansion vessel between .1 and .2 under the system charge when filled cold. with the expansion vessell being set slightly less than the system it expands into to vessell easier. example vessell charge 1 bar system charge 1.1/ 1.2 bar