Flushing central heating

[Daz-]

Hi Guys

I would like to flush my central heating system as it is old and full of sludge, how would i go about this...it is a sealed system

Thanks guys

 

[kevplumb]

see this

 

[Daz-]

Thanks for your help,

one more question though.....to flush a system is it a matter of draining system (after applying chemicals) or do you have to force water around the system using a flushing machine.....

Thanks

 

[ChrisR]

Sealed systems aren't usually too bad. Run a system cleaner for a good time - days or weeks depending which one, then use the mains to shove it through one rad at a time then out. You can use the isolating valves on the combi to prevent all the flow going through the boiler.
The filling loop will do as an IN, but the normal cheap drain cocks are a pain at the OUT. It would help to say instal a compression T where the DC is for flushing, and put a DC in the branch when you're done.

 

[Daz-]

Great thanks for the advice, still learning.....

 

[ChrisR]

If the rads are baddish, as you're only going to be flushing in one direction, half empty the rads at some point. The flow will try harder to go across the bottom, where the grot lies.

 

[Daz-]

Do you half mt rads by venting them ?

 

[kevplumb]

yes while it's draining

 

[Daz-]

Thanks guys..