"Phil L" wrote in message
om...
And would like some information WRT fitting it.
(please no lectures about Corgi registration claptrap)

The old boiler is still working, but not efficiently, and I have to do
jobs on it daily to get it to do it's thing, bits of elastoplast here and
there, string, elastic bands etc and not least, top it up every 6 hours
due to an expansion vessel problem - anyhoo, within days it's going in the
skip, so hurrah! etc.

My main question is about the radiators - they're quite old, at least 15
years, but the plumbing to them and to the existing boiler is only about
8, my idea is to leave everything in place and just swap the boiler,
brilliant! - except....over the past few years, what with all the topping
up etc, there has been no inhibitor in the system and the water now is
akin to crude oil.
I took off all the downstairs rads last year and took them into the back
garden for a spot of hosepipe therapy, and the patio is still stained
black, so my question is this; should I take off all the rads and flush
them out manually (this is not a problem, even with the upstairs ones), or
should I use some other method of flushing out the system, which will also
clean out the pipework inbetween the rads, if so which / what, and how
much? - bearing in mind that I have just forked out my last £240 on a new
boiler.

You don't say if you also have a hot water cylinder, heated from the
boiler...
If you do, you need to treat this as another radiator when flushing out (but
you don't need to disconnect it and take it outside unless you really want
to!

I would suggest doing the following...

Drain system completely (So release as much water as will come out, then
undo all the bleed screws, starting with the highest ones)

Turn off all rads, both lockshield and TRV/normal valve (Making a note of
the number of turns on all the lockshield!)

Remove and hose all rads one at a time, and then replace on wall, but leave
switched off.

Remove old boiler (that's the thing that heats the water, not SWMBO!
(removing SWMBO during the work might be wise though!)

Connect a hose to the pipe that was connected to the boiler CH return (so
water was flowing out of this pipe into the boiler), and direct the other
end to the drain (not the patio!)

Connect another length of hose from the tap to the CH pipe that had the CH
water flowing out of the boiler

Fully turn on the last rad in each branch of the system (In mine, the boiler
is in the middle, so upstairs and downstairs are effectively two separate
branches off the boiler, if you get me) both the lockshield and the TRV (AND
CLOSE THE BLEED SCREW on all the rads!)

Make sure all the rads are off, except the last ones on each branch (It is
actually better to do one branch at a time.

Turn on the water and flush the pipe work (as the bleed screw is not open,
the radiator will not fill up, water should just flow along the bottom)

Run the water until it's clear on this branch

Now, open the next radiator along this branch (REMEMBER THE BLEED SCREW!)
and then (and only then!) turn off the previous radiator.

Go round all the radiators like this, and this should flush all the crap
out.

If you don't have TRV's fitted, do this now, while the system is drained!

Refill and bang in some inhibitor

IANAP (I am not a plumber!), this is just how I would personally approach
it!

Toby...