Changing a combi system to a y plan

[kme]

this sounds a good idea, how would it be wired?sorry if this sounds basic... :coffee

My apologies Monkey; you weren`t the one who caused the issue, AFAIAC

The post which caused my annoyance was:

Would this not cause the rest of the heating system to warm up with a demand calling from the two port valve? Might be wrong. :C

As I said - You had already stated there was a plumber involved; so I expected that a suggestion of an idea would be enough.....

its just a bolt-on (like adding a zone)......

If you "add" a zone, the pre-existing must, by definition, become a zone itself. Ergo, it would need a zone valveheadbang