"charles" wrote in message
...
I was getting localised boiling (kettling) in my GlowWorm boiler when the
pump turned off. I've added ScrewFix Boiler Noise Reducer and that problem
seems to have gone. I now get an alarming clanking instead which I'm sure
wasn't there before.

Any ideas as to what is causing it and how to stop it?

Could be airlock but sludge is also a possibility causing local overheating.
Clanking is caused by steam bubbles forming and collapsing.
(Boiler is still hot, water circulation has stopped)
Causing the pump to run on after the boiler ceases firing is a "fix".
(You can try this to prove the cause)

Boiler needs to be flushed out, ideally by removal and hose pipe applied
outside in the garden.

Most likely in an old system with no water treatment.

I was getting localised boiling (kettling) in my GlowWorm boiler when the
pump turned off. I've added ScrewFix Boiler Noise Reducer and that problem
seems to have gone. I now get an alarming clanking instead which I'm sure
wasn't there before.

Any ideas as to what is causing it and how to stop it?

--
From KT24 in Surrey

Using a RISC OS computer running v5.18

On 13/02/2015 20:26, charles wrote:
I was getting localised boiling (kettling) in my GlowWorm boiler when the
pump turned off. I've added ScrewFix Boiler Noise Reducer and that problem
seems to have gone. I now get an alarming clanking instead which I'm sure
wasn't there before.

Any ideas as to what is causing it and how to stop it?



Air lock? Try turning the pump to full speed for a few minutes.

--
mailto: news {at} admac {dot] myzen {dot} co {dot} uk

"charles" wrote in message
...
In article , harryagain
wrote:

"charles" wrote in message
...
I was getting localised boiling (kettling) in my GlowWorm boiler when
the pump turned off. I've added ScrewFix Boiler Noise Reducer and that
problem seems to have gone. I now get an alarming clanking instead
which I'm sure wasn't there before.

Any ideas as to what is causing it and how to stop it?

Could be airlock but sludge is also a possibility causing local
overheating. Clanking is caused by steam bubbles forming and collapsing.
(Boiler is still hot, water circulation has stopped) Causing the pump to
run on after the boiler ceases firing is a "fix". (You can try this to
prove the cause)

This is not steam bubbles, I've got rid of those.


You might think you have.


There is pump overrun .

Boiler needs to be flushed out, ideally by removal and hose pipe applied
outside in the garden.

It was power flushed two years ago.


A con, "power flushing" has very little effect.

"therustyone" wrote in message
...
On Friday, February 13, 2015 at 8:22:04 PM UTC, charles wrote:
I was getting localised boiling (kettling) in my GlowWorm boiler when the
pump turned off. I've added ScrewFix Boiler Noise Reducer and that
problem


Are you in a hard water area? Could be accumulation of limescale caused
by failure or lack of additives or just many years use. Can be fixed by
Furnox descaler though it's a bit of a hassle.
My boiler tends to sound like my 3KW electric kettle when it's furred up.

Since there is no change of water in a heating system, there can be no
"furring up".

In article , harryagain
wrote:

"charles" wrote in message
...
I was getting localised boiling (kettling) in my GlowWorm boiler when
the pump turned off. I've added ScrewFix Boiler Noise Reducer and that
problem seems to have gone. I now get an alarming clanking instead
which I'm sure wasn't there before.

Any ideas as to what is causing it and how to stop it?

Could be airlock but sludge is also a possibility causing local
overheating. Clanking is caused by steam bubbles forming and collapsing.
(Boiler is still hot, water circulation has stopped) Causing the pump to
run on after the boiler ceases firing is a "fix". (You can try this to
prove the cause)

This is not steam bubbles, I've got rid of those.


There is pump overrun .

Boiler needs to be flushed out, ideally by removal and hose pipe applied
outside in the garden.

It was power flushed two years ago.

Most likely in an old system with no water treatment.

Old system, yes, water treatment also yes.

--
From KT24 in Surrey

Using a RISC OS computer running v5.18

On Friday, February 13, 2015 at 8:22:04 PM UTC, charles wrote:
I was getting localised boiling (kettling) in my GlowWorm boiler when the
pump turned off. I've added ScrewFix Boiler Noise Reducer and that problem


Are you in a hard water area? Could be accumulation of limescale caused by failure or lack of additives or just many years use. Can be fixed by Furnox descaler though it's a bit of a hassle.
My boiler tends to sound like my 3KW electric kettle when it's furred up.

rusty

In article , harryagain
wrote:

"charles" wrote in message
...
In article , harryagain
wrote:

"charles" wrote in message
...
I was getting localised boiling (kettling) in my GlowWorm boiler when
the pump turned off. I've added ScrewFix Boiler Noise Reducer and
that problem seems to have gone. I now get an alarming clanking
instead which I'm sure wasn't there before.

Any ideas as to what is causing it and how to stop it?

Could be airlock but sludge is also a possibility causing local
overheating. Clanking is caused by steam bubbles forming and
collapsing. (Boiler is still hot, water circulation has stopped)
Causing the pump to run on after the boiler ceases firing is a "fix".
(You can try this to prove the cause)

This is not steam bubbles, I've got rid of those.


You might think you have.


There is pump overrun .

Boiler needs to be flushed out, ideally by removal and hose pipe
applied outside in the garden.

It was power flushed two years ago.


A con, "power flushing" has very little effect.

You are wrong there.

--
From KT24 in Surrey

Using a RISC OS computer running v5.18

In article , harryagain
wrote:

"therustyone" wrote in message
...
On Friday, February 13, 2015 at 8:22:04 PM UTC, charles wrote:
I was getting localised boiling (kettling) in my GlowWorm boiler when
the pump turned off. I've added ScrewFix Boiler Noise Reducer and that
problem


Are you in a hard water area? Could be accumulation of limescale
caused by failure or lack of additives or just many years use. Can be
fixed by Furnox descaler though it's a bit of a hassle. My boiler
tends to sound like my 3KW electric kettle when it's furred up.

Since there is no change of water in a heating system, there can be no
"furring up".

We've found the source of the noise. One of the zone valves was sticking
and closed with a "bang" rather than gently easing shut. This one had a
manual lever and I've opened/closed it a few times. Noise gone.

--
From KT24 in Surrey

Using a RISC OS computer running v5.18

In article ,
charles wrote:
I was getting localised boiling (kettling) in my GlowWorm boiler when
the pump turned off. I've added ScrewFix Boiler Noise Reducer and that
problem seems to have gone. I now get an alarming clanking instead which
I'm sure wasn't there before.

Any ideas as to what is causing it and how to stop it?

I used to get that with my old cast iron Potterton boiler. Cleaning didn't
seem to help. I added a pump over-run circuit which kept it running for a
minute or so after things told it to stop.

--
*Support bacteria - they're the only culture some people have *

Dave Plowman London SW
To e-mail, change noise into sound.

On Sun, 15 Feb 2015 08:28:11 +0000 (GMT), charles
wrote:

In article , harryagain
wrote:

"charles" wrote in message
...
In article , harryagain
wrote:

"charles" wrote in message
...
I was getting localised boiling (kettling) in my GlowWorm boiler when
the pump turned off. I've added ScrewFix Boiler Noise Reducer and
that problem seems to have gone. I now get an alarming clanking
instead which I'm sure wasn't there before.

Any ideas as to what is causing it and how to stop it?

Could be airlock but sludge is also a possibility causing local
overheating. Clanking is caused by steam bubbles forming and
collapsing. (Boiler is still hot, water circulation has stopped)
Causing the pump to run on after the boiler ceases firing is a "fix".
(You can try this to prove the cause)

This is not steam bubbles, I've got rid of those.


You might think you have.


There is pump overrun .

Boiler needs to be flushed out, ideally by removal and hose pipe
applied outside in the garden.

It was power flushed two years ago.


A con, "power flushing" has very little effect.

You are wrong there.

There's no need to state the "Bleedin' Obvious" back at Harryagain in
this news group. Most everybody here _know_ he's wrong. :-)

Since he 'harries' this NG again and again, his nom de plume is well
chosen.
--
J B Good

In article ,
"harryagain" writes:
Since there is no change of water in a heating system, there can be no
"furring up".

Systems that leak do change water. This can easily go unnoticed
for a long time if automatically refilled from a header tank.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

In article ,
"Dave Plowman (News)" writes:
In article ,
charles wrote:
I was getting localised boiling (kettling) in my GlowWorm boiler when
the pump turned off. I've added ScrewFix Boiler Noise Reducer and that
problem seems to have gone. I now get an alarming clanking instead which
I'm sure wasn't there before.

Any ideas as to what is causing it and how to stop it?

I used to get that with my old cast iron Potterton boiler. Cleaning didn't
seem to help. I added a pump over-run circuit which kept it running for a
minute or so after things told it to stop.

I wonder if it has a pump run-on timer which has died?

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

In article ,
Andrew Gabriel wrote:
In article ,
"Dave Plowman (News)" writes:
In article ,
charles wrote:
I was getting localised boiling (kettling) in my GlowWorm boiler when
the pump turned off. I've added ScrewFix Boiler Noise Reducer and
that problem seems to have gone. I now get an alarming clanking
instead which I'm sure wasn't there before.

Any ideas as to what is causing it and how to stop it?

I used to get that with my old cast iron Potterton boiler. Cleaning
didn't seem to help. I added a pump over-run circuit which kept it
running for a minute or so after things told it to stop.

I wonder if it has a pump run-on timer which has died?

No. Was a BE type.

--
*The closest I ever got to a 4.0 in school was my blood alcohol content*

Dave Plowman London SW
To e-mail, change noise into sound.