by plumbbob »
Sat Oct 11, 2008 2:17 pm
I wouldn't have thought a gravity fed system is fitted with a tank thermostat and anyway, it would not reduce the water temp whilst the heating was on.
If this is the case, and you have a standard gravity system the only way to reduce the hot water temperature without modifying the system is to reduce the boiler stat. You haven't mentioned what make of boiler you have but if it's solid fuel, then you are stuck as is. Of course, the spin off to this would be reduced radiator temperature.
Maybe a zone valve could be fitted in the gravity circuit and linked to a tank stat, but that all depends on your system design. As to cost, well that is difficult as this is not a standard job, and I can't tell what's involved, but I can't see it being done competently for less than £200.