Power Flush

[luty]

Plumber recently suggested my CH seating needs flushing to get rid of the black sludge building up in a radiator he bled. Said it would be around £400. I bled all radiators and only the ones on middle floor had black water coming out, all others were clear and water in boiler was clear (he said when he was fixing it).

Its a combi boiler (potterton puma 100) and the question is, how difficult is it to remove three radiators in turn and clean them out rather than paying for the whole system to be flushed?

Thanks in advance for any suggestions (helpful or otherwise )

 

[bathjobby]

Close the valves on each end of the rads, crack the connectors, open the bleed valves and empty the rads into a suitable container. Fully disconnect the valves, take the rads outside and flush through with a hose (not on your patio, it will stain), refit, open valves. If you think this is localised sludge, probably better doing it this way rather than blasting it around the rest of the system too.

 

[luty]

Thanks for that, pretty much what I thought. I've got Drayton TV4s (?) on a couple of the radiators, if I turn these to 0 will that be good enough to cut the flow from that end or is there another way?

 

[ChrisR]

Yes unless they get cold, then they'll open. Take the top off the TRV4 head (unscrew knurled ring) and you'll see a small pin sticking up. Rest something like a 5p piece on it then replace the head (with head set to max). Now as you turn towards 0 you'll feel the tap shut - don't overdo it!

When you have the rad in the garden with a n other, part fill with water then invert repeatedly, with hand over the hole. This forces water up and down the vertical channels in the rad.

If the radiators get fully hot though, including at the bottom, leave it, just put some more inhibitor in (eg Sentinel X100).