With heating only set ON my upstairs rads get hot. Which component/valve is at fault? Is it the 3 way Honeywell divertor valve I have next to hot water tank in airing cupboard? It has a switch on it which can be set to AUTO or MANUAL. Mine is in the middle! (kids I reckon!) Which way should it be set?
For the record I t's a gravity fed system with a baxi back boiler.
Thanks for any help. :)
