2 radiators not working (have bled no air) any ideas

[jfk]

Hi I have 2 radiators upstairs in my house, running of a gravity fed heating system. They used to work untill recently. I have bled them and theirs water in both. I tried removing the rads and pulling water through each pipe using a hose untill hot/clear water came through, when I re attached the rads and filled them they heated up for about 5 mins then went cold. The radiators did have alot of thick sludge in when removed and I flushed them through with a hose COULD THEY BE BLOCKED Up?. I also tried shutting of the rads in the other rooms to force the heating their wayth no effect. They are not trv's. Do I need new rads or is their something else I can try??
Cheers J

 

[Phil]

It sound like a blockage due to sludge, recommend using a sludge remover like Fernox F3 or Sentinal X400. Follow the instructions and leave in the system for the recommended time. Dont just pour it into the F&E tank when its full or it will just sit in the tank, drain some off, add sludge remover and top up.

 

[mrgas]

i know its the more exspensieve alternative but if your pipework and rads are continually blocking up with sludge then a powerflush would seem your best option all done and in a few hours no time waiting like with chemicals and powerflushing removes almost 100% of the sludge. if you do go ahead with this option make sure your pipework and fittings are half decent powerflushing has been known to make a joint leak..good luck whatever you decide

 

[Deleted member 2053]

If this is gravity fed then the chances are it is a single pipe system. If so Powerflushing is a bit of a waste of time as you cannot force the chemicals through the radiators under pressure. Kamco do a chemical called hyperflush which I think is better than a lot of the alternatives. Put in one can per 100 litres and give it a couple of weeks to do its stuff.