I need to fit an expansion vessel next to an Ideal mini combi boiler. The pressure fluctuates ++. Presurising the boiler expansion tank has made no difference.
Can I just T an external 18l expansion vessel directly into the return pipe? There already is a pressure guage and water pressurising circuit fitted to the boiler.
The return pipe is 22mm.

Julian, March 2009

yes , all an expansion vessel does is accomodate the expanded water in your heating system, it can be fitted any where suitable, does n't need to be in your face next to the boiler, if boiler is fitted in kitchen for example. are you sure the exp' vessel has gone though(press air valve on exp vessel you should hear air escaping like letting down a tyre if no air ,it might just need pumping back up ,...if water comes out air valve then the vessel has gone)

papmcg, March 2009

You can fit in return pipe as you said no matter where you branch off

Mr K, March 2009