Flushing a system?

[Dirntknow]

I'm looking to run a sludge 'remover' to my combi system before changing the secondary heat exchanger and had this idea in mind: (Worcester 280)
Put hose pipe on a down stairs drain point and open. As the system empties open the filling loop to replenish as it drains to minimze air locks and apply a little pressure.
Why you may ask? I don't see the point of adding a sludge remover to old and dirty water! Is this a good or bad idea?

 

[onlyfitidealboilers]

well i didn't see the point putting it new & clean wtr!!

so why do u think people make sludge remover?

 

[combispecialist]

u need it properly flushing mate,these quick fixes are only a short term benefit,the plate will soon block up again

 

[Dirntknow]

I wouldn't add Fairy Liquid to dirty dish water so for the sake of an hour or so it can only get a bit cleaner?

 

[Agile]

Try to wash out as much of the dirty water as you can.

Then add X400 and wait four weeks or X800 and wait four hours whilst running the heating. Then drain it all out and add an inhibitor like X100.

Tony

 

[Dirntknow]

Try to wash out as much of the dirty water as you can.

Tony

Thaks for the confirmation, I couldn't get my head around adding a cleaner to dirty water!
Any comments on my drain/fill method? I'll be draining it fully at a later point to fix a slightly wet joint but didn't see the point of draining it fully just yet til I'm ready to do the work...