Have a gravity central heating system. When ot water Only is selected the first radiatior in the circuit gets hot. Obviously this is a problem in the summer!
Would this likely be the non-return valve stuck open?
The valve is very difficult to get to as it's down behind the boiler. I assume that the valve points downwards..is this correct?
Is there any problem in just leaving it as it is and turning off the affected radiator during the summer?
sPoNiX