Flushing Combi boiler central heating though fill loop?

[FredFF]

Hi

Many thanks in advance for your help.

I’ve a 10 year old system with a Remeha Avanta Plus 28C boiler with 6 radiators. Only one radiator has a drainage tap - it is the only one on a floor below all the others. I have drained the system and run X400 through it with the heating on constantly for ~30 hours - all rads open. Didn’t have time to run for longer unfortunately as the work needs to be finished in the next few days. Then drained, filled and run for 15 minutes, drained, filled and run for 15 minutes and drained again. Water is still very brown but I guess that’s no surprise.

Just wondering if I should do more beyond re-filling and adding X100? One thought is to turn off all the rads except one, leave the drainage tap open and then turn on the mains through the filling loop and wait for it to run through clear, then move on to the next radiator etc. If I do this should I turn off the inflow and outflow valves to the boiler? I’d rather not take off a radiator if possible.

Thanks again!
Fred

 

[Mottie]

That’s been keeping you awake looking at the time of your post! To me, that sounds like it should flush most of the water out of the system. If you did it while the rads are hot, you’d be able to feel whether it had got all the water out of each rad (cold water may only flow across bottom of rad). Then do a final fill, run and drain on the whole system. I can’t think why that wouldn’t work. You’d only need to close one valve on each radiator to stop the flow. No doubt I’ll be corrected if I’m even the slightest bit wrong!

 

[oilboffin]

To do the job properly you need a flushing pump.Bob

 

[DP]

Fred do what you have already done a few more times.

 

[FredFF]

Many thanks for your responses I will just fill, circulate and empty a few more times.

@Motman - yes not a lot of sleep with littlun in the house...