Can anyone diagnose this? Towel rail in family bathroom, and radiator in en-suite have started coming on when the thermostat calls for hot water. Radiators are all off otherwise, as these two should be as well. Any ideas? Thanks!
I had this problem, the three port valve had a build up of limescale on it and so was never closing the line to the central heating fully, this meant that hot water was leaking into the central heating systembut becuase of the low volume/pressure it was only noticeable on the first rad in the loop. I replaced the three port valve over two years ago now and the problem has never recurred.
Thanks lawrie. Any particular brand thats with getting or avoiding? Seems quite big price differences after a quick Google
I have a Drayton, I only replaced the valve itself not the actuator. The other cheap option is to take the valve off and clean it, I have done that before but it's an awkward job, there's not really any space in the pipe to get in there and scrub!
Just ceck it is that by turning off the bathroom rad to see if the fault moves to the next radiator before changing the valve.