I have recently noticed my radiators upstairs are warm and some are red hot even though the control panel is not on. I've bled all radiators a couple of times to balance the system. Today I notice the bolier had fired up but the control panel was not on. A couple of upstairs radiators are very hot particularly the one in the en-suite and bathroom. Is there anything else I can do to solve the problem or do I need to call a plumber?.
In reply to buildersmate - I've only noticed the radiators becoming warm due to the good weather. The programmable room thermostat is switched off so the bolier shouldn't fire up but it does!. I thought I'd bleed the radiators to get rid of air locks and rectify the problem, but it hasn't. The hot water cylinder is just over a year old and the boiler was serviced recently.