Central heating problems

[Northy]

Heating wouldn't work last night without the hot water heat turned on and then didn't work at all for the Mrs when she got home this lunch time.

Plumber called, dicked about in the airing cupboard for 10 seconds, back down to the kitchen, off she went again, but now he says we have to have the hot water on for the heating to work. We never used to until last night.

Has he bodged it? He she to the Mrs we'll probably need a new "part" soon, but wasn't specific.

I think he's done something to the 3 position valve? It's a pain having to have the hot water on too, it's not really fixed is it?

3 position valve was new last year and pump the year before.

Anyone understand this stuff? We're not on Combi, old type with tank in airing cupboard, whatever that's called.

G