Any top tips on flushing the system

[johnh66]

Hi All

I have posted on here before about the heating system. Bit of background..had a motorised valve replaced about 4 weeks ago. At the time pump was found to be clogged and a fair bit of sludge in the pump. Some radiators downstairs didnt come on and some upstairs not that hot. I put 2 tubs of x400 in 4 weeks ago and run the system after a few days all the rads are now on and all are getting very hot..Now for the flush and refill with x100.

I was going to do the following...please bear in mind ive never done this before..
turn off water and heating system
drain water from 4 rads downstairs that have drain valves on until no water comes out.
refill system and repeat until water is clear then put x100 in
bleed rads

or

run heating and start to flush rad still leaving the water on
repeat on all rads downstairs with drain valves
when clear water off and heating off
drain level until enough water out to put in x100
refill and bleed rads

Any tops tips?

Cheers
John

 

[Robiow70]

I would go with your first idea, but running the system first to warm up wont hurt.

Make sure you open all the lockshield valves and Trv's if fitted to fully open to help get the muck out.

Hope this helps Rob

When you open the lockshield valve write down on a bit of paper, how many turns you do, so you can close them down to the same setting they were on.