DIY Doctor UK DIY Forums

Hi,

I have a freestanding potterton boilder, i thinks its the type that fills itself and the heating system up automatically after a drain down, ie not a header tank or a filling loop.

some of my radiators are getting hot at the top but staying cold at the bottom. a friend suggested that its because they are fouled up and chemical treatment needs to be added. how do i do this? can i take off a radiator, drain it then add the sludge remover to that? if so, how do i stop it all draining out onto the floor when i try to refit?

many thanks in advance for any advice!

chris

You have to be fairly quick, pick a small radiator and fill with the descaler/sludge remover you need a small radiator because you have to put both thunbs over each end of the radiator, can be quite difficult.

Or, turn off mains cold water, drain heating system abit and add to the header tank for the heating. Then turn on cold water and refill rads

MAKE SURE ITS NOT THE HOT WATER TANK

thanks for the advice.. managed to add sludge remover to a small radiator as suggested. however this does not seem to have solved the problem.

one radiator gets hot only at the top (suggesting sludge), some only get luke warm, and one does not get hot at all, not even the pipes leading to it. a friend suggested it might be airlocked. how do i remove an airlock?

he boiler seems to be an odd set up - no header tank so i think its mains fed but there is no filling loop or pressure gauge that one normally sees.

is there a third type of boiler system? if so, how do i get the airlock out, its been suggested to use a hosepipe connected to the cold tap in the kitchen but wont the pressure damage the boiler?