This idea is probably crazy, but I'd like to hear why.

This mission is to flush the CH, including rads without removing rads.
(I have some rads not getting as hot as I believe they should - the
usual LSV adjustments and bleeding has been done). I believe some rads
have been in there 35 years.

1. Close all rad valves and LSVs
2. Turn boiler to minimum (just on to allow pump to work)
3. Turn pump to maximum speed.
4. Open up CH drain tap (the header feed can fill faster than it will
drain.)
5. Let run for (say) 10 mins

(1 through 5 flush out the pipework)

6. Fully open the valve and LSV of one rad.
7. Let run for (say) 10 mins
8. Close the valve and LSV.
9. Move on to next rad.

(6 through 9 flush out one rad at a time)

10. Set system back to normal.

A little knowledge is a dangerous thing. I have very little plumbing
knowledge so I could be extremely dangerous.

Just thinking aloud.
Great newsgroup.

Thanks in advance.
Stan

I'm beginning to think maybe it was a crazy idea.
If it doesn't go precisely to plan, the boiler and/or pump may be at
risk.

Ah well, just thinking outside the box.

In an earlier contribution to this discussion,
Stanley Morgan wrote:

This idea is probably crazy, but I'd like to hear why.

This mission is to flush the CH, including rads without removing rads.
(I have some rads not getting as hot as I believe they should - the
usual LSV adjustments and bleeding has been done). I believe some rads
have been in there 35 years.

1. Close all rad valves and LSVs
2. Turn boiler to minimum (just on to allow pump to work)
3. Turn pump to maximum speed.
4. Open up CH drain tap (the header feed can fill faster than it will
drain.)
5. Let run for (say) 10 mins

(1 through 5 flush out the pipework)

6. Fully open the valve and LSV of one rad.
7. Let run for (say) 10 mins
8. Close the valve and LSV.
9. Move on to next rad.

(6 through 9 flush out one rad at a time)

10. Set system back to normal.

A little knowledge is a dangerous thing. I have very little plumbing
knowledge so I could be extremely dangerous.

Just thinking aloud.
Great newsgroup.

Thanks in advance.
Stan

If the pump is pushing water towards the drain tap, there's *no* *way* that
the header will fill faster than it drains - and you'll end up with
cavitation in the pump.

Chances are that there's a direct route from header tank to drain tap which
*doesn't* go through any radiators - so it probably won't flush the rads
very well.

Why not bite the bullet and remove the rads - one at a time - and give them
a good wash out with a hosepipe. While each rad is off, open each of its
valves in turn - and drain until it runs clear - to flush out that section
of the pipework. Depending on the layout of your pipework, you may need to
be a bit creative in order to find a way of flushing the pipes which go to
the boiler and back.
--
Cheers,
Roger
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PLEASE REPLY TO NEWSGROUP!

On Fri, 03 Oct 2008 16:29:07 +0000, Stanley Morgan wrote:

This idea is probably crazy, but I'd like to hear why.

This mission is to flush the CH, including rads without removing rads.
(I have some rads not getting as hot as I believe they should - the
usual LSV adjustments and bleeding has been done).

Have you tried balancing the system? I find that the usual cause of rads
not heating up, rarely total blockage.

I believe some rads
have been in there 35 years.

1. Close all rad valves and LSVs
2. Turn boiler to minimum (just on to allow pump to work)
3. Turn pump to maximum speed.
4. Open up CH drain tap (the header feed can fill faster than it will
drain.)
5. Let run for (say) 10 mins

(1 through 5 flush out the pipework)

6. Fully open the valve and LSV of one rad.
7. Let run for (say) 10 mins
8. Close the valve and LSV.
9. Move on to next rad.

(6 through 9 flush out one rad at a time)

10. Set system back to normal.

If you know the pipework arrangement and know that the feed into the
system is into the opposite part of the system from the drain-off cock
(e.g. feed into return, DOC on flow) then what you propose is good. Often
you'll find the drain takes water almost directly from the feed, but even
then the one-radiator at a time procedure should help flush a certain
amount out.



--
YAPH http://yaph.co.uk

I'd give my right arm to be ambidextrous

"YAPH" wrote in message
...
On Fri, 03 Oct 2008 16:29:07 +0000, Stanley Morgan wrote:

This idea is probably crazy, but I'd like to hear why.

This mission is to flush the CH, including rads without removing rads.
(I have some rads not getting as hot as I believe they should - the
usual LSV adjustments and bleeding has been done).

Have you tried balancing the system? I find that the usual cause of rads
not heating up, rarely total blockage.

I believe some rads
have been in there 35 years.

1. Close all rad valves and LSVs
2. Turn boiler to minimum (just on to allow pump to work)
3. Turn pump to maximum speed.
4. Open up CH drain tap (the header feed can fill faster than it will
drain.)
5. Let run for (say) 10 mins

(1 through 5 flush out the pipework)

6. Fully open the valve and LSV of one rad.
7. Let run for (say) 10 mins
8. Close the valve and LSV.
9. Move on to next rad.

(6 through 9 flush out one rad at a time)

10. Set system back to normal.

If you know the pipework arrangement and know that the feed into the
system is into the opposite part of the system from the drain-off cock
(e.g. feed into return, DOC on flow) then what you propose is good. Often
you'll find the drain takes water almost directly from the feed, but even
then the one-radiator at a time procedure should help flush a certain
amount out.



--
YAPH http://yaph.co.uk

I'd give my right arm to be ambidextrous

I am doing mine tomorrow. I added some Sentinel X400 (sludge remover) a few
months ago.

I plan to drain down fully. Refill, then drain down again. Then keep my
hose on the drain point and just let the system refil / drain for a few
minutes.

I am doing mine tomorrow. I added some Sentinel X400 (sludge remover) a few
months ago.

I plan to drain down fully. Refill, then drain down again. Then keep my
hose on the drain point and just let the system refil / drain for a few
minutes.


Hi Slider,
In the end I decided for a slightly less ambitious and dangerous
approach, and coincidentally I also purchased Sentinel X400 this
weekend (I think £14 at B&Q).
I've already drained down and put it in, refilled and bled.

I thought I'd run it for a week with valves and LSVs in usual
position. Then note positions and run a week with everything fully
open.

I like your idea about keeping it running (ie draining and filling at
same time for extra flushing.

Cheers,
Stan

On Mon, 06 Oct 2008 10:26:01 GMT, Stan
wrote:


I am doing mine tomorrow. I added some Sentinel X400 (sludge remover) a few
months ago.

I plan to drain down fully. Refill, then drain down again. Then keep my
hose on the drain point and just let the system refil / drain for a few
minutes.


Hi Slider,
In the end I decided for a slightly less ambitious and dangerous
approach, and coincidentally I also purchased Sentinel X400 this
weekend (I think £14 at B&Q).
I've already drained down and put it in, refilled and bled.

I thought I'd run it for a week with valves and LSVs in usual
position. Then note positions and run a week with everything fully
open.

I like your idea about keeping it running (ie draining and filling at
same time for extra flushing.

Cheers,
Stan

To remove deposits you need 'velocity' so the water will entrain the
deposits. The amount of deposits removed by simply draining a gravity
system is very limited and is hardly 'flushing'..

"Edward W. Thompson" wrote in message
...

On Mon, 06 Oct 2008 10:26:01 GMT, Stan
wrote:


I am doing mine tomorrow. I added some Sentinel X400 (sludge remover) a
few
months ago.

I plan to drain down fully. Refill, then drain down again. Then keep my
hose on the drain point and just let the system refil / drain for a few
minutes.


Hi Slider,
In the end I decided for a slightly less ambitious and dangerous
approach, and coincidentally I also purchased Sentinel X400 this
weekend (I think £14 at B&Q).
I've already drained down and put it in, refilled and bled.

I thought I'd run it for a week with valves and LSVs in usual
position. Then note positions and run a week with everything fully
open.

I like your idea about keeping it running (ie draining and filling at
same time for extra flushing.

Cheers,
Stan

To remove deposits you need 'velocity' so the water will entrain the
deposits. The amount of deposits removed by simply draining a gravity
system is very limited and is hardly 'flushing'..

True, but evry little bit helps. Let me guess, you work for a "flushing"
company :-)

"Slider" wrote in message ...

"Edward W. Thompson" wrote in message
...

On Mon, 06 Oct 2008 10:26:01 GMT, Stan
wrote:


I am doing mine tomorrow. I added some Sentinel X400 (sludge remover) a
few
months ago.

I plan to drain down fully. Refill, then drain down again. Then keep
my
hose on the drain point and just let the system refil / drain for a few
minutes.


Hi Slider,
In the end I decided for a slightly less ambitious and dangerous
approach, and coincidentally I also purchased Sentinel X400 this
weekend (I think £14 at B&Q).
I've already drained down and put it in, refilled and bled.

I thought I'd run it for a week with valves and LSVs in usual
position. Then note positions and run a week with everything fully
open.

I like your idea about keeping it running (ie draining and filling at
same time for extra flushing.

Cheers,
Stan

To remove deposits you need 'velocity' so the water will entrain the
deposits. The amount of deposits removed by simply draining a gravity
system is very limited and is hardly 'flushing'..

True, but evry little bit helps. Let me guess, you work for a "flushing"
company :-)


Well I did mine yesterday, bit of a pain as all the downstairs rads have to
be drained individually. Drained from the kitchen rad which drained all
upstairs and itself. Then had to go round and drain the other 5 downstairs
individually. Anyway, kept the hose and two of the rads, the kitchen one
and the larger lounge one and just let the system fill then drain for about
15 minutes. Refilled and bled and all good now. I added 1.5 litres of
Sentinel X100 inhibitor so all is good now. I bled the bathroom rad late
last night and all that came out was clear water!! :-)

I agree, not as good as a professional powerflush but they cost big bucks.

snip

I bled the bathroom rad late last night and all that came out was
clear water!! :-)

I agree, not as good as a professional powerflush but they cost big
bucks.


Slider,
How long did you leave the sludge remover in the system ?
Did you run it with all valve and LSVs fully open with sludge remover
in ?
When you were letting the system refill and drain simultaneously, did
you have none/some/all air vents open ?

It sounds like you got a great result if bleeding gave you clear, not
back water.

Stan

"Stan" wrote in message
...
snip

I bled the bathroom rad late last night and all that came out was
clear water!! :-)

I agree, not as good as a professional powerflush but they cost big
bucks.


Slider,
How long did you leave the sludge remover in the system ?
Did you run it with all valve and LSVs fully open with sludge remover
in ?
When you were letting the system refill and drain simultaneously, did
you have none/some/all air vents open ?

It sounds like you got a great result if bleeding gave you clear, not
back water.

Stan



How long did you leave the sludge remover in the system ?

Sludge remover has been in the system since probably June / July, although
the heating has only been on the last month or so.

Did you run it with all valve and LSVs fully open with sludge remover
in ?

Never toucher the LSVs. I balanced the system back in May, so didn't want
to change anything.

When you were letting the system refill and drain simultaneously, did
you have none/some/all air vents open ?

I bled all the rads whilst refilling / draining until all the air was
expelled, then left it filling / draining for about 15 mins