DIY Doctor UK DIY Forums

I'm planning to install a new combi boiler, but I'm advised that flushing the system first is necessary. Howevever, in the interests of economy, I'd like to avoid the cost of getting it back-flushed. I've no problem draining the central heating system down and re-filling, but will that do the trick?

Any advice for a DIY'er?

Hi,

Power flushing would be best but, you can drain & refill a few times until no sludge remains (some will remain) then push mains water thru the rads at suitable points.

Hth

check the manufacturer's guarantee carefully - some state that a power flush is necessary. if you don't do it you might absolve them of responsibility if any manufacurer's faults develop with your boiler during the guarantee period.

hi there, if your current boiler is running fine, just chuck some sentinel X400 into a radiator. I know a council that do this and they rarely have trouble due to blockages and they never powerflush...

this is what the website says so follow the instructions:

"1 litre of Sentinel X400 is sufficient to treat a typical domestic system of 8 to 10 radiator panels. Larger systems should be dosed with 2 litres. To clean an existing system in accordance with BS7593: Sentinel X400 should be circulated, preferably at normal operating temperature, with all valves open and the pump turned to a maximum flow for a minimum period of 2 hours or until satisfactory performance is restored. Where systems are badly fouled, a longer period of circulation (e.g., up to 4 weeks) is recommended, but the product will not clear a completely blocked pipe"

That should clean up your system enough for a new boiler to be installed.

For the record, I powerflush, but this is a far cheaper way of clearing.

Regards,

AH.