My brother has been told by a plumber he cannot have a power flush on his
central heating system as it uses 8mm microbore.

Is that true?

Adam

On Mon, 29 May 2006 16:35:44 +0100, ARWadsworth wrote
(in article ) :

My brother has been told by a plumber he cannot have a power flush on his
central heating system as it uses 8mm microbore.

Is that true?

Adam



Power flushing machines that I've seen connect in place of the pump and work
by circulating a chemical solution through the radiators one at a time - i.e.
the operator is supposed to go round and close all radiator valves and then
open at one radiator at a time. This is meant to flush through crud in the
radiators and it gets filtered at the power flushing machine or to the drain

One can figure out that if the radiators are badly silted up, that this could
be difficult through 8mm tube even though the lengths from the manifold are
typically only a few mm.

I suspect that the plumber is saving himself some grief in case the job is
unsuccessful or that it takes him longer than he'd like to do it.


I have an 8mm system which has been well looked after from the outset.

The approach that I took when exchanging boilers and switching to a sealed
system was to do the sealed system conversion first - this provided a means
to fill and flush the system from the mains rather than the roof tank.

I drained the system and then starting closest to the boiler, I visited each
radiator in turn and removed it. Care is needed because sludge is an
indellible dye. I covered the floor with plastic sheet and old towels and
used a cat litter tray under each valve. The radiator valve unions can be
undone. Fit a small plastic bag on each tail with a rubber band and take
radiator outside. Flush through with a pressure washer. At the radiator
turn off the valves and turn on the mains water at the filling loop.
You can then flush any crud in the pipes out. `Since the pipes are only
8mm, there is not going to be a lot to come out and it is not being pushed
around the pipes either.

I repeated this for each radiator and then refitted everything and added a
chemical flushing agent. The system was run hot for a few days and then
flushed to drain with fresh water. Finally, corrosion inhibitor was added.

The whole job can be done easily in a morning.

On Mon, 29 May 2006 15:35:44 +0000, ARWadsworth wrote:

My brother has been told by a plumber he cannot have a power flush on his
central heating system as it uses 8mm microbore.

If a system with micro-bore pipe ever gets to be in need of a power flush
it is truly beyond any hope of redemption.

Frankly the idea of disturbing what little dirt there may be in such a
system out of the rads into the pipes looks like madness. besides which
the power flush flow rate in each radiator will be fairly small due to the
resistance of the 8mm pipe.

A flushing out of individual removed radiators (with a pressure washer if
you must) is all that should be done.

--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html
Choosing a Boiler FAQ http://www.makewrite.demon.co.uk/BoilerChoice.html
Gas Fitting Standards Docs he http://www.makewrite.demon.co.uk/GasFittingStandards

"Ed Sirett" wrote in message
news
On Mon, 29 May 2006 15:35:44 +0000, ARWadsworth wrote:

My brother has been told by a plumber he cannot have a power flush on his
central heating system as it uses 8mm microbore.

If a system with micro-bore pipe ever gets to be in need of a power flush
it is truly beyond any hope of redemption.

Frankly the idea of disturbing what little dirt there may be in such a
system out of the rads into the pipes looks like madness. besides which
the power flush flow rate in each radiator will be fairly small due to the
resistance of the 8mm pipe.

A flushing out of individual removed radiators (with a pressure washer if
you must) is all that should be done.

--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html
Choosing a Boiler FAQ http://www.makewrite.demon.co.uk/BoilerChoice.html
Gas Fitting Standards Docs he
http://www.makewrite.demon.co.uk/GasFittingStandards


I also have an 8mm system with the TwinFast Yorkshire valves (flow and
return coaxial at one end). I always remove radiators for decorating and
have never found much sludge. My main worry is sediment settling in
horizontal (or sagging) lengths of pipe. I am surprised that Ed feels that
flushing would not help. I wouldn't mind trying it - I imagine a pump that
sends shock waves through the water would be effective.
Incidentally - I have not found any faults with the twin valve arrangement
and can't understand why it became obsolete. It can be a very neat
installation and much easier to remove radiators. Mine have a nylon tube to
send the flow to the far end. I understand some people used metal and
suffered from corrosion. Was the problem a lack of understanding?
I think my house was the last in the road to use this system (1988) as an
identical house completed a few weeks later by the same plumber had
conventional valves on each end. Does anyone know when my type of valve fell
from favour?

I also have an 8mm system with the TwinFast Yorkshire valves (flow and
return coaxial at one end). I always remove radiators for decorating and
have never found much sludge. My main worry is sediment settling in
horizontal (or sagging) lengths of pipe. I am surprised that Ed feels that
flushing would not help. I wouldn't mind trying it - I imagine a pump that
sends shock waves through the water would be effective.
Incidentally - I have not found any faults with the twin valve arrangement
and can't understand why it became obsolete. It can be a very neat
installation and much easier to remove radiators. Mine have a nylon tube
to send the flow to the far end. I understand some people used metal and
suffered from corrosion. Was the problem a lack of understanding?
I think my house was the last in the road to use this system (1988) as an
identical house completed a few weeks later by the same plumber had
conventional valves on each end. Does anyone know when my type of valve
fell from favour?


Sorry - I meant MAXITWIN valve:
http://tinyurl.com/asr5x

"John" wrote in message
...

"Ed Sirett" wrote in message
news
On Mon, 29 May 2006 15:35:44 +0000, ARWadsworth wrote:

My brother has been told by a plumber he cannot have a power flush on
his
central heating system as it uses 8mm microbore.

If a system with micro-bore pipe ever gets to be in need of a power flush
it is truly beyond any hope of redemption.

Frankly the idea of disturbing what little dirt there may be in such a
system out of the rads into the pipes looks like madness. besides which
the power flush flow rate in each radiator will be fairly small due to
the
resistance of the 8mm pipe.

A flushing out of individual removed radiators (with a pressure washer
if
you must) is all that should be done.

--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html
Choosing a Boiler FAQ http://www.makewrite.demon.co.uk/BoilerChoice.html
Gas Fitting Standards Docs he
http://www.makewrite.demon.co.uk/GasFittingStandards


I also have an 8mm system with the TwinFast Yorkshire valves (flow and
return coaxial at one end). I always remove radiators for decorating and
have never found much sludge. My main worry is sediment settling in
horizontal (or sagging) lengths of pipe. I am surprised that Ed feels that
flushing would not help. I wouldn't mind trying it - I imagine a pump that
sends shock waves through the water would be effective.
Incidentally - I have not found any faults with the twin valve arrangement
and can't understand why it became obsolete. It can be a very neat
installation and much easier to remove radiators. Mine have a nylon tube
to send the flow to the far end. I understand some people used metal and
suffered from corrosion. Was the problem a lack of understanding?
I think my house was the last in the road to use this system (1988) as an
identical house completed a few weeks later by the same plumber had
conventional valves on each end. Does anyone know when my type of valve
fell from favour?




======================
Twin entry valves had a reputation for being difficult to get the
circulation going. I don't think it was a serious problem but it certainly
could be difficult at times. There was some debate about long the internal
pipe should be and whether it should be plastic or copper. I used copper
about 2/3rds the length of the radiator (as recommended) and always got a
good circulation going eventually.

As far as flushing is concerned I can only guess that it's less necessary
with 8mm because the normal pumped flow has a more powerful scouring action
than is the case with 15mm or greater. I've never had any blocked pipes,
possibly because I don't have a Summer shutdown. I think our weather is too
unpredictable to have a fixed Summer period when heating isn't necessary.

Cic.

On Mon, 29 May 2006 18:23:02 +0000, John wrote:


"Ed Sirett" wrote in message
news
On Mon, 29 May 2006 15:35:44 +0000, ARWadsworth wrote:

My brother has been told by a plumber he cannot have a power flush on his
central heating system as it uses 8mm microbore.

If a system with micro-bore pipe ever gets to be in need of a power flush
it is truly beyond any hope of redemption.

Frankly the idea of disturbing what little dirt there may be in such a
system out of the rads into the pipes looks like madness. besides which
the power flush flow rate in each radiator will be fairly small due to the
resistance of the 8mm pipe.

A flushing out of individual removed radiators (with a pressure washer if
you must) is all that should be done.

--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html
Choosing a Boiler FAQ http://www.makewrite.demon.co.uk/BoilerChoice.html
Gas Fitting Standards Docs he
http://www.makewrite.demon.co.uk/GasFittingStandards


I also have an 8mm system with the TwinFast Yorkshire valves (flow and
return coaxial at one end). I always remove radiators for decorating and
have never found much sludge. My main worry is sediment settling in
horizontal (or sagging) lengths of pipe. I am surprised that Ed feels that
flushing would not help. I wouldn't mind trying it - I imagine a pump that
sends shock waves through the water would be effective.
Incidentally - I have not found any faults with the twin valve arrangement
and can't understand why it became obsolete. It can be a very neat
installation and much easier to remove radiators. Mine have a nylon tube to
send the flow to the far end. I understand some people used metal and
suffered from corrosion. Was the problem a lack of understanding?
I think my house was the last in the road to use this system (1988) as an
identical house completed a few weeks later by the same plumber had
conventional valves on each end. Does anyone know when my type of valve fell
from favour?

Mainly because the older units had copper internals which corroded and
broke as they were in contact with the iron. This caused only the corner
to get hot.

They are not as widely available and whilst a thermostatic version is
probably available the requirement to add TRVs to most radiators make
their replacement nigh on inevitable.


--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html
Choosing a Boiler FAQ http://www.makewrite.demon.co.uk/BoilerChoice.html
Gas Fitting Standards Docs he http://www.makewrite.demon.co.uk/GasFittingStandards

They are not as widely available and whilst a thermostatic version is
probably available the requirement to add TRVs to most radiators make
their replacement nigh on inevitable.


--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html
Choosing a Boiler FAQ http://www.makewrite.demon.co.uk/BoilerChoice.html
Gas Fitting Standards Docs he
http://www.makewrite.demon.co.uk/GasFittingStandards


Good point - hadn't thought about the infernal requirement to fit
thermostatic valves - but how a sensor only inches from the heat source can
work properly is beyond me.

"Andy Hall" wrote in message
...
On Mon, 29 May 2006 16:35:44 +0100, ARWadsworth wrote
(in article ) :

My brother has been told by a plumber he cannot have a power flush on his
central heating system as it uses 8mm microbore.

Is that true?

Adam



Power flushing machines that I've seen connect in place of the pump and
work
by circulating a chemical solution through the radiators one at a time -
i.e.
the operator is supposed to go round and close all radiator valves and
then
open at one radiator at a time. This is meant to flush through crud in
the
radiators and it gets filtered at the power flushing machine or to the
drain

One can figure out that if the radiators are badly silted up, that this
could
be difficult through 8mm tube even though the lengths from the manifold
are
typically only a few mm.

I suspect that the plumber is saving himself some grief in case the job is
unsuccessful or that it takes him longer than he'd like to do it.

I hope not, he wants me to rewire his house!

I have an 8mm system which has been well looked after from the outset.

Unfortunatley, this system is 15 years old and has been neglected before my
brother bought the house

The approach that I took when exchanging boilers and switching to a sealed
system was to do the sealed system conversion first

Can I do that without changing the hot water cylinder?

- this provided a means
to fill and flush the system from the mains rather than the roof tank.

I drained the system and then starting closest to the boiler, I visited
each
radiator in turn and removed it. Care is needed because sludge is an
indellible dye. I covered the floor with plastic sheet and old towels
and
used a cat litter tray under each valve. The radiator valve unions can
be
undone. Fit a small plastic bag on each tail with a rubber band and take
radiator outside. Flush through with a pressure washer. At the
radiator
turn off the valves and turn on the mains water at the filling loop.
You can then flush any crud in the pipes out. `Since the pipes are only
8mm, there is not going to be a lot to come out and it is not being pushed
around the pipes either.

I removed all the rads and flushed them last year when he moved in. I also
changed the pump which was noisy and added inhibitor. The main problem is
now of overpumping which as I understand will reduce the effectiveness of
the inhibitior and the sound of water falling down the vent pipe when the
pump shuts off. I removed a rad over the weekend and although there was
plenty of black water there was not the sludge that was present a year ago.


I repeated this for each radiator and then refitted everything and added a
chemical flushing agent. The system was run hot for a few days and then
flushed to drain with fresh water. Finally, corrosion inhibitor was
added.



I think I may reflush the rads and this time use a cleanser.

Adam

"Ed Sirett" wrote in message
news
On Mon, 29 May 2006 15:35:44 +0000, ARWadsworth wrote:

My brother has been told by a plumber he cannot have a power flush on his
central heating system as it uses 8mm microbore.

If a system with micro-bore pipe ever gets to be in need of a power flush
it is truly beyond any hope of redemption.

All of it or just the rads? I am prepared to swap them if needs be.


Frankly the idea of disturbing what little dirt there may be in such a
system out of the rads into the pipes looks like madness. besides which
the power flush flow rate in each radiator will be fairly small due to the
resistance of the 8mm pipe.

A flushing out of individual removed radiators (with a pressure washer if
you must) is all that should be done.

Cheers Ed, see my reply to Andy

Adam

On Mon, 29 May 2006 21:54:39 +0000, John wrote:


They are not as widely available and whilst a thermostatic version is
probably available the requirement to add TRVs to most radiators make
their replacement nigh on inevitable.



Good point - hadn't thought about the infernal requirement to fit
thermostatic valves - but how a sensor only inches from the heat source can
work properly is beyond me.

Little heat is trasnferred by radiation especially from the lower part of
the rad.
The convection draughts keep the TRV more in tune with the room that the
radiator.
The TRV does not have to be at the same temp as the room but merely has to
sense and react to changes in the room temp.

--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html
Choosing a Boiler FAQ http://www.makewrite.demon.co.uk/BoilerChoice.html
Gas Fitting Standards Docs he http://www.makewrite.demon.co.uk/GasFittingStandards

On Tue, 30 May 2006 17:30:07 +0000, ARWadsworth wrote:


"Ed Sirett" wrote in message
news
On Mon, 29 May 2006 15:35:44 +0000, ARWadsworth wrote:

My brother has been told by a plumber he cannot have a power flush on his
central heating system as it uses 8mm microbore.

If a system with micro-bore pipe ever gets to be in need of a power flush
it is truly beyond any hope of redemption.

All of it or just the rads? I am prepared to swap them if needs be.

15mm can and do block on very badly sludged systems. It won't take so much
to block an 8mm pipe. I have no idea wether an 8mm pipe is unblockable by
pressure and chemicals alone - but I'd reckon against it.





--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html
Choosing a Boiler FAQ http://www.makewrite.demon.co.uk/BoilerChoice.html
Gas Fitting Standards Docs he http://www.makewrite.demon.co.uk/GasFittingStandards

"Ed Sirett" wrote in message
news
On Tue, 30 May 2006 17:30:07 +0000, ARWadsworth wrote:


"Ed Sirett" wrote in message
news
On Mon, 29 May 2006 15:35:44 +0000, ARWadsworth wrote:

My brother has been told by a plumber he cannot have a power flush on
his
central heating system as it uses 8mm microbore.

If a system with micro-bore pipe ever gets to be in need of a power
flush
it is truly beyond any hope of redemption.

All of it or just the rads? I am prepared to swap them if needs be.

15mm can and do block on very badly sludged systems. It won't take so much
to block an 8mm pipe. I have no idea wether an 8mm pipe is unblockable by
pressure and chemicals alone - but I'd reckon against it.

S**t. Any more chance of being successfull in a soft water area. I am now
only hoping for miracles.

Adam

ARWadsworth wrote:
"Ed Sirett" wrote in message
15mm can and do block on very badly sludged systems. It won't take so much
to block an 8mm pipe. I have no idea wether an 8mm pipe is unblockable by
pressure and chemicals alone - but I'd reckon against it.

S**t. Any more chance of being successfull in a soft water area. I am now
only hoping for miracles.

Soft or hard water probably won't affect scale in CH systems...
if you flush the radiators through, then I should think that the
reduction in total sludge in the system, combined with the fact
that small bore pipes have a high flow rate, and radiators are
nice "settlement tanks", might help.

On Tue, 30 May 2006 18:28:13 +0100, ARWadsworth wrote
(in article ) :


"Andy Hall" wrote in message
...
On Mon, 29 May 2006 16:35:44 +0100, ARWadsworth wrote
(in article ) :

My brother has been told by a plumber he cannot have a power flush on his
central heating system as it uses 8mm microbore.

Is that true?

Adam



Power flushing machines that I've seen connect in place of the pump and
work
by circulating a chemical solution through the radiators one at a time -
i.e.
the operator is supposed to go round and close all radiator valves and
then
open at one radiator at a time. This is meant to flush through crud in
the
radiators and it gets filtered at the power flushing machine or to the
drain

One can figure out that if the radiators are badly silted up, that this
could
be difficult through 8mm tube even though the lengths from the manifold
are
typically only a few mm.

I suspect that the plumber is saving himself some grief in case the job is
unsuccessful or that it takes him longer than he'd like to do it.

I hope not, he wants me to rewire his house!

I have an 8mm system which has been well looked after from the outset.

Unfortunatley, this system is 15 years old and has been neglected before my
brother bought the house







The approach that I took when exchanging boilers and switching to a sealed
system was to do the sealed system conversion first

Can I do that without changing the hot water cylinder?

It should be possible in principle. However, if it's a hard water area the
coil might be scaled up. You would need to take out the immersion heater
and look inside to check that. If it is, then you could descale with
chemicals and replace the immersion heater. However, this may not be the
best way to invest in the system. It might be better to write off the
cylinder and start with a new one,...



- this provided a means
to fill and flush the system from the mains rather than the roof tank.

I drained the system and then starting closest to the boiler, I visited
each
radiator in turn and removed it. Care is needed because sludge is an
indellible dye. I covered the floor with plastic sheet and old towels
and
used a cat litter tray under each valve. The radiator valve unions can
be
undone. Fit a small plastic bag on each tail with a rubber band and take
radiator outside. Flush through with a pressure washer. At the
radiator
turn off the valves and turn on the mains water at the filling loop.
You can then flush any crud in the pipes out. `Since the pipes are only
8mm, there is not going to be a lot to come out and it is not being pushed
around the pipes either.

I removed all the rads and flushed them last year when he moved in. I also
changed the pump which was noisy and added inhibitor. The main problem is
now of overpumping which as I understand will reduce the effectiveness of
the inhibitior and the sound of water falling down the vent pipe when the
pump shuts off. I removed a rad over the weekend and although there was
plenty of black water there was not the sludge that was present a year ago.


I repeated this for each radiator and then refitted everything and added a
chemical flushing agent. The system was run hot for a few days and then
flushed to drain with fresh water. Finally, corrosion inhibitor was
added.



I think I may reflush the rads and this time use a cleanser.


That's reasonably easy to do and would give an idea of the general state of
the system as well.




Adam

On Mon, 29 May 2006 17:38:59 +0100, Andy Hall wrote:

On Mon, 29 May 2006 16:35:44 +0100, ARWadsworth wrote
(in article ) :

My brother has been told by a plumber he cannot have a power flush on his
central heating system as it uses 8mm microbore.

Is that true?

Adam



Power flushing machines that I've seen connect in place of the pump and work
by circulating a chemical solution through the radiators one at a time - i.e.
the operator is supposed to go round and close all radiator valves and then
open at one radiator at a time. This is meant to flush through crud in the
radiators and it gets filtered at the power flushing machine or to the drain

One can figure out that if the radiators are badly silted up, that this could
be difficult through 8mm tube even though the lengths from the manifold are
typically
only a few mm.


" a few mm" ?????

On Sat, 3 Jun 2006 15:06:03 +0100, Stuart wrote
(in article ):

On Mon, 29 May 2006 17:38:59 +0100, Andy Hall wrote:

On Mon, 29 May 2006 16:35:44 +0100, ARWadsworth wrote
(in article ) :

My brother has been told by a plumber he cannot have a power flush on his
central heating system as it uses 8mm microbore.

Is that true?

Adam



Power flushing machines that I've seen connect in place of the pump and
work
by circulating a chemical solution through the radiators one at a time -
i.e.
the operator is supposed to go round and close all radiator valves and then
open at one radiator at a time. This is meant to flush through crud in
the
radiators and it gets filtered at the power flushing machine or to the drain

One can figure out that if the radiators are badly silted up, that this
could
be difficult through 8mm tube even though the lengths from the manifold are
typically
only a few mm.


" a few mm" ?????



Well, yes. Maybe a couple of thousand for example.....

What's that between friends.?

On Monday, 29 May 2006 16:35:44 UTC+1, ARWadsworth wrote:
My brother has been told by a plumber he cannot have a power flush on his
central heating system as it uses 8mm microbore.

Is that true?

Adam

--------------------------

Power flushing is not very effective on microbore because the drop in flow is big with small pipes. Try a powder flush as it has been developed especially for microbore systems and use much stronger machines.

wrote:
On Monday, 29 May 2006 16:35:44 UTC+1, ARWadsworth wrote:
My brother has been told by a plumber he cannot have a power flush
on his central heating system as it uses 8mm microbore.

Is that true?

Adam

--------------------------

Power flushing is not very effective on microbore because the drop in
flow is big with small pipes. Try a powder flush as it has been
developed especially for microbore systems and use much stronger
machines.

Well I will bear that advice with a pinch of salt. After all you are
replying to a post I made in 2006. We swapped the pipework to 15mm a few
years later.

Any ideas of how to clear a turd from the uk.d-i-y newsgroup in the year
2012?


--
Adam

Power flushing is not very effective on microbore because the drop in
flow is big with small pipes. Try a powder flush as it has been
developed especially for microbore systems and use much stronger
machines.

Well I will bear that advice with a pinch of salt. After all you are
replying to a post I made in 2006. We swapped the pipework to 15mm a few
years later.

Any ideas of how to clear a turd from the uk.d-i-y newsgroup in the year
2012?

fit an enema fitting to the end of the power flush hose...