Help and advice please - upgrade to independant h/w and c/h

[D_Hailsham]

An ABV does not provide a path unless there is a pump fitted.

A passive path would normally be a gravity cylinder heating coil.

Agreed. But isn't that stating the obvious?

We know the OP has a pump, so what is the point you are trying to make??

 

[fergusondj]

A quick update for anyone who's interested - fitted a valve on the H/W water circuit before the tee to the feed and expansion and all seems to be working just fine.

Thanks to all who offered advice - complicated stuff this central heating lark!

 

[D_Hailsham]

A quick update for anyone who's interested - fitted a valve on the H/W water circuit before the tee to the feed and expansion

Is there still an open path from the boiler to the feed and expansion tee when the valve is closed?

 

[fergusondj]

Absolutely - that's a mistake I wouldn't have wanted to make!