hi guys im new here so go easy on me. only joking 
anyway my problem is for the last 2 months ive been getting problems with my heating. for the first month or so it would come on and the radiators would heat but if i left it on for about 3-4 hours the radiators would go cold and the boiler would not come back on for several hours or if the radiators were on and i put the water on to heat at the same time the same would happen. one of the times it went off whilst examining it i switched the pump off and on, heard water come into the boiler and a minute later it fired up again. thinking maybe an airlock causing overheating (as whatever way my system was plumbed an airlock is common if the system is drained and refilled) i took off a radiator put the hose with mains pressure on the valve and blew it till it came out the overflow, this normally fixes the airlock problem if the system has been drained for example to put on a new radiator with new valves and it did the job, the heating worked fine and i could heat water at the same time.
however after about 2 days the problem came back although now when the heating goes off the power to the pump and thermostat go off too and nothing works for a few hours again. so i tried the hose trick again and it worked again however after another day i was back to square one and now when i put the heating on the radiators start to heat but by the time they get lukewarm the boiler shuts off and wont fire up for a couple of hours. i think it is overheating somehow but im not sure why. the hose thing working would make it appear to me that air could be getting into the system someway but i cant see how, i also thought maybe the pump was not performing properly but didnt want to go buying a new pump if thats not the issue.
by the way my system is a gravity fed system with tank in the attic and boiler in a purpose built outhouse in my back garden.
cheers in advance
anyway my problem is for the last 2 months ive been getting problems with my heating. for the first month or so it would come on and the radiators would heat but if i left it on for about 3-4 hours the radiators would go cold and the boiler would not come back on for several hours or if the radiators were on and i put the water on to heat at the same time the same would happen. one of the times it went off whilst examining it i switched the pump off and on, heard water come into the boiler and a minute later it fired up again. thinking maybe an airlock causing overheating (as whatever way my system was plumbed an airlock is common if the system is drained and refilled) i took off a radiator put the hose with mains pressure on the valve and blew it till it came out the overflow, this normally fixes the airlock problem if the system has been drained for example to put on a new radiator with new valves and it did the job, the heating worked fine and i could heat water at the same time.
however after about 2 days the problem came back although now when the heating goes off the power to the pump and thermostat go off too and nothing works for a few hours again. so i tried the hose trick again and it worked again however after another day i was back to square one and now when i put the heating on the radiators start to heat but by the time they get lukewarm the boiler shuts off and wont fire up for a couple of hours. i think it is overheating somehow but im not sure why. the hose thing working would make it appear to me that air could be getting into the system someway but i cant see how, i also thought maybe the pump was not performing properly but didnt want to go buying a new pump if thats not the issue.
by the way my system is a gravity fed system with tank in the attic and boiler in a purpose built outhouse in my back garden.
cheers in advance
