Right, have inspected the F&E tank. Filled with water, stopcock working, no apparent blockages. There was some fine rusty sludge, a little like algae in a pond but the water was generally clear. It appears that the water level has been going up and down by a couple of inches judging by the 'tide...
Hi,
It really is an SD but definitely not a combi (have had a combi in a previous house)! Retro-fitted a few years ago now to a much older (and needlessly complicated) gravity system. Hot water tank in airing cupboard, header in loft all present and correct!
Any thoughts?
I have a Saunier Duval boiler in a pumped, gravity gas central heating system. Having started using the heating again I've noticed that our hot water is going cold if hot water and heating run at the same time. If only the hot water is running then all is fine.
I don't really know where to go...