draining ch system

[pandaman]

I have to drain my open vented ch system, I have had X400 circulating for a month to try and desludge it. there is what I would call a 'proper' drain tap above the boiler which you can fit a hosepipe to. I presume I can drain the upper part of the system from this tap. However there is no such tap on the lower part of the system, instead there is only the small drain taps fitted to all the ground floor rads. I had to drain a bucket full out before putting in the X400 and it took ages as the water just trickles out. There is a screw nut on these taps. do they come right off? Do I just drain from 1 tap or will I have to go round them all in turn? Looks like it may take a while. How much water approx would the system hold excluding the expansion tank. It is a 3 bed house with 6 rads downstairs (one a double) and 5 upstairs. Any advice welcome.

 

[gas4you]

If the rads are all on drops,you will have to drain each one.

Hard to say how much a ch system holds, they all vary.

Try opening the drain offs a bit further to improve the flow out.

I would flush the system out with clean water for a while afterwards as well.

Don't forget to go up and clean the expansion tank out

 

[John506]

Are the pipes on the downstairs radiators going from the valves then travelling up towards the ceiling most likely boxed in?

If so, as gas4you said, you will need to drain individually.

 

[pandaman]

thanks gas4you and dave, pipes from rads all go straight into wall, so looks like its down to draining each one as you say. Thanks for advice.
can I just say what a great site this is for plumbing advice, there is nearly always someone who will try to help.