Blocked radiator

[draconia]

Hi there

I've been having some problems with radiators blocking on a microbore system (flexible piping). Four years ago I drained, treated with a cleaner and flushed the system and refilled along with corrosion inhibitor.

Recently some of the ground floor radiators have refused to heat. Two of these proved to be clogged in the pipe to the thermostat with debris - little black flakes-, which was easily cleared using a piece of wire down the pipe. In the latest one this hasn't worked and my adventures in the crawl space under the floor have proved fruitless. I'm guessing there is a blockage somewhere that the 3 metre wire I'm using can't reach. Can anyone recommend a treatment that'll dissolve the blockage as it's unlikely at my age I'll survive anymore adventures under the floor! Note that all the other radiators are fine and it's only the supply to the radiator that shows no flow, the valve heats eventually but thats about it. Disconnecting the outlet from the radiator shows clear water in the return pipe. I had thought about draining the system in the hope the flow would disrupt it, but with my luck it'll be stubborn!

Thanks in advance!

 

[oilman]

I think the only treatment that will work here is to powerflush the system, as you will get forward and reverse flow which may dislodge the blockage. If yours is an open vented system, you need to refresh the corrosion inhibitor every two or at the most, three years.