Strange one this – addED sentinel x800 to my system a month ago and have been flusHing it out this afternoon to get it ready for some inhibitor. Expected to get coal black water – instead I get clean water with a nice tight foam head (Boddingtons would be proud)
20 year old system
all valves open
last flushed five years ago
WTF?

Never used the stuff myself, every time i’ve had to drain the system it always looks good enough to drink, boiler servicing is another dark art i don’t partake in either.

I guess that means no air is getting into the system so no corrosion and a healthy system. Leave it alone 😉

Or all the sediment is just sitting at the bottom of the rads…

Take them off and flush them with a hosepipe.

It’ll only get rid of so much stuff because you’re using your central heating pump to push it round so it’s only got the same amount of flow as you’d normally get to force anything out. Anything that’s been there a while will still be there.