On 2008-05-31 13:53:13 +0100, John Stumbles said:

On Sat, 31 May 2008 10:12:07 +0100, Andy Hall wrote:

While you're at it, fitting a strainer with stainless steel mesh on the
return to the boiler is a good idea.

Not unless you can guarantee getting every last scrap of debris out of the
system: a small amount of crud is enough to block the strainer up and stop
circulation through the system.

Depends on the design of strainer.

I found one with a large area of strainer because it's about 100mm high
It has a red cap on the end to cover the bleed connection, making it
look, to all intents and purposes like a phallus.

On Sat, 31 May 2008 16:01:59 +0100, geoff wrote:

drop the pressure, funnel and tube into the top of a radiator


Doesn't work for rads with small vent plugs welded straight into the rad
(rather than 1/2"BSP plugs) or where the 1/2" tapping goes into an
immediate 90 degree elbow into the rad itself - tend to get liquid running
out of the hole and spilling back down the rad. IME anyway.

--
John Stumbles

I used to be forgetful but now I ... um ....

On 2008-06-01 11:05:46 +0100, John Stumbles said:

On Sat, 31 May 2008 16:01:59 +0100, geoff wrote:

drop the pressure, funnel and tube into the top of a radiator


Doesn't work for rads with small vent plugs welded straight into the rad
(rather than 1/2"BSP plugs) or where the 1/2" tapping goes into an
immediate 90 degree elbow into the rad itself - tend to get liquid running
out of the hole and spilling back down the rad. IME anyway.

For these, the effective solution is to drain this particular radiator
(only) and to use one of the cartridge gel products.

I have found that trying to use these as suggested by the manufacturers
- i.e. against the system pressure - results in water ****ing out where
the nozzle is screwed into the radiator. Having empty space into
which to inject and no pressure works well. Then remove the nozzle,
refit vent plug part way and refill radiator.

Andy Hall wrote:
On 2008-05-29 08:11:37 +0100, Lobster
said:

Andy Hall wrote:
On 2008-05-28 20:35:28 +0100, Mark said:


Thanks for all the replies. I have looked at hiring a power flusher
but the only one I can find is about £100 and it doesn't mention use
in a sealed system.

Yes it will work with a sealed system. £100 is a reasonable price.

How do you actually attach power flushers to the CH system? Do you
need to provide a special port or something?


Usually they hook into the pump position - at least on ones that I've seen.

Having been sufficiently interested to look at the instructions myself
(as I think I might well take the plunge and do this to my own
system over the summer - long overdue) I do find it a bit confusing.

I think I'd need to do this by removing the utility room rad and hooking
the flusher up there (my pump being buried inside my system boiler).
Would I then leave the boiler CH flow and return valves open for the
whole flushing process (which surely is necessary for a "circuit"), or
should they be closed off?

The instructions seem to be saying you flush each rad separately in
situ, several times in both directions, by going round the house and
closing off all other rads; is that about right? Still sounds pretty
time-consuming and laborious. It also indicates having a tankfull of
chemical-laced water which is used for the flushing - with 16 rads in my
house apparently to be flushed separately, (with all the dead volume of
pipework each time) isn't that going to be a massive amount of cleaner?!
Or am I misunderstanding the process?

David

On 2008-06-01 14:32:15 +0100, Lobster said:

Andy Hall wrote:
On 2008-05-29 08:11:37 +0100, Lobster said:

Andy Hall wrote:
On 2008-05-28 20:35:28 +0100, Mark said:


Thanks for all the replies. I have looked at hiring a power flusher
but the only one I can find is about £100 and it doesn't mention use
in a sealed system.

Yes it will work with a sealed system. £100 is a reasonable price.

How do you actually attach power flushers to the CH system? Do you need
to provide a special port or something?


Usually they hook into the pump position - at least on ones that I've seen.

Having been sufficiently interested to look at the instructions myself
(as I think I might well take the plunge and do this to my own
system over the summer - long overdue) I do find it a bit confusing.

I think I'd need to do this by removing the utility room rad and hooking
the flusher up there (my pump being buried inside my system boiler).
Would I then leave the boiler CH flow and return valves open for the
whole flushing process (which surely is necessary for a "circuit"), or
should they be closed off?


I think that you would have to look at the instructions with the
machine, but I think I would want to avoid anything that involves the
possibility of water contaminated with sludge solids passing through
the boiler.




The instructions seem to be saying you flush each rad separately in
situ, several times in both directions, by going round the house and
closing off all other rads; is that about right? Still sounds pretty
time-consuming and laborious. It also indicates having a tankfull of
chemical-laced water which is used for the flushing - with 16 rads in
my house apparently to be flushed separately, (with all the dead volume
of pipework each time) isn't that going to be a massive amount of
cleaner?! Or am I misunderstanding the process?

David

I believe that the point is that the cleaner is circulated around under
pressure and filtered at the tank before circulating again. It is
time consuming, which is why it's expensive to have it done
professionally

But to answer your question differently, it was why I came up with the
idea of removing radiators one at a time and then flushing with fresh
water at each radiator valve one at a time as I went. This makes
sure that anything in the pipes is always flushed to waste rather than
radiator sludge being circulated around the system.

Since most of the grot collects in the radiators, it seemed better to
disturb them as little as possible other than empting them and then to
take them outside for a good flush through with a pressure washer.

On Sun, 1 Jun 2008 13:38:05 +0100, Andy Hall
wrote:

On 2008-06-01 11:05:46 +0100, John Stumbles said:

On Sat, 31 May 2008 16:01:59 +0100, geoff wrote:

drop the pressure, funnel and tube into the top of a radiator


Doesn't work for rads with small vent plugs welded straight into the rad
(rather than 1/2"BSP plugs) or where the 1/2" tapping goes into an
immediate 90 degree elbow into the rad itself - tend to get liquid running
out of the hole and spilling back down the rad. IME anyway.

For these, the effective solution is to drain this particular radiator
(only) and to use one of the cartridge gel products.

I have found that trying to use these as suggested by the manufacturers
- i.e. against the system pressure - results in water ****ing out where
the nozzle is screwed into the radiator. Having empty space into
which to inject and no pressure works well. Then remove the nozzle,
refit vent plug part way and refill radiator.

I'll do it this way, thanks :-)