rcooke25552 Posted November 17, 2013 Report Share Posted November 17, 2013 Hi all. Iv been helping my cousin who recently moved into his new house (an old farm house) which has a log burner feeding the central heating system. That is the only means of heat. There is also no thermostat just pump on or off. So the problems haha. Well the first time we lit the fire earlier this week, the radiators heated up but took about 4 hours to get to red hot. Is this normal? Since then we have tried bleeding the air but there was a problem with the f and e tank so the system wasn't refilling. We fixed that with some messing around and filled and bled the system but the radiators still weren't get hot in te middle so we left it at that point. Since then all week we have been lighting the fire but they simply aren't getting hot. Sort of luke warm after hours. So today we drained the system and took all the rads off in turn and flushed them through with a hose and got loads of **** out of them. Then refilled system and added a cleaner and bled all radiators in proper order etc and lit the fire. An hour passed and they still weren't warm so we started messing with the pump which turned out to be on it's lowest setting. We turned it up to 3 but wouldn't work on that, would only operate on one so some more messing around got the pump working on 3. But still the radiators aren't getting hot. This is really starting to baffle us both so I'm turning to you guys to hopefully give us some more advice. Sorry it's so long haha Quote Link to comment Share on other sites More sharing options...
figgy Posted November 17, 2013 Report Share Posted November 17, 2013 Your not getting enough flow through the radiators. The pipes are probably choked up and the pump dont sound too good,let the cleaner do its stuff and when you drain the system fit a new pump. figgy Quote Link to comment Share on other sites More sharing options...
rcooke25552 Posted November 17, 2013 Author Report Share Posted November 17, 2013 Figgy another thing I forgot to mention is the pipes either side of the pump aren't getting particularly hot either (located right behind the fire). Would this be pump or ? Quote Link to comment Share on other sites More sharing options...
vampire Posted November 17, 2013 Report Share Posted November 17, 2013 If it was taking 4 hours to get hot,then the cleaner you put in didnt circulate either,so leave it longer then drain/fill/ bleed properly,drain some out of a drain valve when its full,you should hear it go. Quote Link to comment Share on other sites More sharing options...
Tim Kelly Posted November 17, 2013 Report Share Posted November 17, 2013 Sounds like there may well be an air lock somewhere. Does the pump sound like it's cavitating when you turn it from 1 to 3? Does water come out of the silver screw in the middle of the pump if you loosen it? Try shutting down all the rads except the closest one and see if you can get that hot, then gradually add radiators. Quote Link to comment Share on other sites More sharing options...
four-wheel-drive Posted November 17, 2013 Report Share Posted November 17, 2013 (edited) I would be a bit worried if the radiators are not getting hot if you have a good fire if the water is not flowing to the radiators to cool down it could well explode or is the hot water going to the overflow tank. Edited November 17, 2013 by four-wheel-drive Quote Link to comment Share on other sites More sharing options...
magman Posted November 17, 2013 Report Share Posted November 17, 2013 Maybe a none return valve fitted that has seized up I would be a bit worried if the radiators are not getting hot if you have a good fire if the water is not flowing to the radiators to cool down it could well explode as kill you or is the hot water going to the overflow tank. Should have an open vent so wouldn't happen Quote Link to comment Share on other sites More sharing options...
Yellow Bear Posted November 17, 2013 Report Share Posted November 17, 2013 Should have an open vent so wouldn't happen Good point - is the F&E tank getting hot? Quote Link to comment Share on other sites More sharing options...
monster1971 Posted November 17, 2013 Report Share Posted November 17, 2013 hi does the wood burner heat a hot water cylinder as well as the rads , if so there should be an injector tee on the return from the cylinder and a low limit stat on the return which controls when the pump turns on . do you know if the system has ever worked properly as if its incorrectly set up you are on a hiding to nothing. gravity hot water systems arent the norm anymore and take some knowledge to get them right. monster Quote Link to comment Share on other sites More sharing options...
figgy Posted November 17, 2013 Report Share Posted November 17, 2013 I'd be looking at why the back boiler is not getting the pipes hot close to the fire. These pipes would be scalding hot and start boiling if the water was heating up and not circulating. Best get it looked at by a qualified Heating Engineer, as the back boiler on a natural fire cannot be controlled by a stat the temperatures are normally a lot higher and cause more furring up of the back boiler and rads, especially if no inhibitor was in the system as back boilers are usually cast iron or steel. You could try flushing out the back boiler with a hose connected to one pipe and another length to a drain off the other conection when all is cooled. Figgy Quote Link to comment Share on other sites More sharing options...
Paul223 Posted November 17, 2013 Report Share Posted November 17, 2013 I'd be looking at why the back boiler is not getting the pipes hot close to the fire. These pipes would be scalding hot and start boiling if the water was heating up and not circulating. Figgy Indeed. Unless the back boiler is in the pumping loop for some reason and the rads are getting rid of the heat before it can be produced Quote Link to comment Share on other sites More sharing options...
four-wheel-drive Posted November 17, 2013 Report Share Posted November 17, 2013 Maybe a none return valve fitted that has seized up Should have an open vent so wouldn't happen The point is we or he dose not now who fitted it in so anything could happen what things should have and what they do are not the same at all I say he would do best to have it looked at by someone who knows what they are doing it may cost money but best to be safe than sorry. Quote Link to comment Share on other sites More sharing options...
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