A few weeks ago, I checked on here as to what was the situation with regard
to doing work on my daughter's bathroom water, as she had one of those new
fangled boilers with lots of pipes connected to it. The general advice was
that if the power was cut, and the water input was shut off at the rising
main stop-tap, I could just go ahead and disconnect her bath and so on, and
then just restore water and power at the end. Well, today, it just got a bit
more complicated. She has now decided that she wants the radiator changing
to one of those 'ladder' types as well, so my new question is, given that
the boiler will be off by virtue of the input water and power being off, is
there anything else I need to do either before disconnecting the old
radiator, or after hooking up the new one, apart from bleeding it,
obviously? From memory, the boiler is an Alpha CB24X.

Being a daughter, she has total faith in her dear old dad, but I must
confess that I am not looking forward to this job, as I have never worked on
anything other than a traditional system with indirectly heated hot water in
a storage tank, and the talk I see on here of pressurising modern systems
with footpumps and so on, puts me off a bit.

The taps for her new bath have the large size of inlet, but the pipes going
there are 15mm. Also, the space is very tight behind that end of the bath,
and there are also a pair of 15mm pipes tee'd in to feed an existing shower.
To make it all a lot easier to couple up, I would like to pre-assemble the
taps onto the bath, and come off them with 15mm flexis with a push-fit
remote end. Is there a flexi made, which has 15mm push collar at one end,
and 22mm tap connector at the other, or am I going to have to fit a 22mm
connector, followed by a 22 to 15 reducer ? Or is there a threaded adaptor
available ? Or what is the recommended way of getting from 22 to 15 via a
flexi tail ? All useful advice appreciated before Saturday, when it all
begins ... :-\

Arfa

Arfa Daily wrote:
She has now decided that she wants the radiator changing
to one of those 'ladder' types as well, so my new question is, given that
the boiler will be off by virtue of the input water and power being off, is
there anything else I need to do either before disconnecting the old
radiator, or after hooking up the new one, apart from bleeding it,
obviously?

It is doubtful that the new radiator will be a straight fit onto the old
taps. So you'll need new taps as well as some 15mm pipe, as the new rad
is likely to be thinner in width, hence the pipe will need extending.
Drain off the central heating water firstly. You should need to empty
the system, just to drop the level below the lowest point you are going
to work on. To help, turn off all of the other raditator valve before
commencing, as you wont have to wait for them to drain then.
Put some inhibitor in when you refill.

Being a daughter, she has total faith in her dear old dad, but I must
confess that I am not looking forward to this job, as I have never worked on
anything other than a traditional system with indirectly heated hot water in
a storage tank, and the talk I see on here of pressurising modern systems
with footpumps and so on, puts me off a bit.

The taps for her new bath have the large size of inlet, but the pipes going
there are 15mm.

Loads of different flexis are available for pipe to tap connections. Get
a Screwfix catalogue, or look at their website for the various
options.There should be available what you require in push-fit, though i
have never bought push fit - I think compression are better for such
places.

Also be prepared at have to adjust the waste outlet, not all baths have
the waste in the same place.
Alan.
--
To reply by e-mail, change the ' + ' to 'plus'.

In article ,
Arfa Daily wrote:
Being a daughter, she has total faith in her dear old dad, but I must
confess that I am not looking forward to this job, as I have never
worked on anything other than a traditional system with indirectly
heated hot water in a storage tank, and the talk I see on here of
pressurising modern systems with footpumps and so on, puts me off a bit.

In terms of working on it there's little real difference between a
pressurized heating system and an open one. Basically the header tank is
replaced with a pressure vessel (usually part of the boiler assembly)
which should need no attention after a drain down and refill. The filling
point is usually at the boiler and needs to be connected to a mains
pressure supply - but this should all be in place and pretty obvious. One
real benefit is the mains pressure means far less chances of airlocks.
Once the system is filled and bled the water supply should be turned off
and disconnected.

--
*And don't start a sentence with a conjunction *

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

On Sep 24, 2:31*am, "Arfa Daily" wrote:
A few weeks ago, I checked on here as to what was the situation with regard
to doing work on my daughter's bathroom water, as she had one of those new
fangled boilers with lots of pipes connected to it. The general advice was
that if the power was cut, and the water input was shut off at the rising
main stop-tap, I could just go ahead and disconnect her bath and so on, and
then just restore water and power at the end. Well, today, it just got a bit
more complicated. She has now decided that she wants the radiator changing
to one of those 'ladder' types as well, so my new question is, given that
the boiler will be off by virtue of the input water and power being off, is
there anything else I need to do either before disconnecting the old
radiator, or after hooking up the new one, apart from bleeding it,
obviously? From memory, the boiler is an Alpha CB24X.

Being a daughter, she has total faith in her dear old dad, but I must
confess that I am not looking forward to this job, as I have never worked on
anything other than a traditional system with indirectly heated hot water in
a storage tank, and the talk I see on here of pressurising modern systems
with footpumps and so on, puts me off a bit.

The taps for her new bath have the large size of inlet, but the pipes going
there are 15mm. Also, the space is very tight behind that end of the bath,
and there are also a pair of 15mm pipes tee'd in to feed an existing shower.
To make it all a lot easier to couple up, I would like to pre-assemble the
taps onto the bath, and come off them with 15mm flexis with a push-fit
remote end. Is there a flexi made, which has 15mm push collar at one end,
and 22mm tap connector at the other, or am I going to have to fit a 22mm
connector, followed by a 22 to 15 reducer ? Or is there a threaded adaptor
available ? Or what is the recommended way of getting from 22 to 15 via a
flexi tail ? All useful advice appreciated before Saturday, when it all
begins ... * :-\

Arfa



Have you checked the power of the new 'ladder type' rad? These fancy
rads often give much less heat than the normal type. her bathroom
will be colder.
Robert

On Sep 24, 2:31*am, "Arfa Daily" wrote:
...

also, it is really true or just and urban myth that you need to be
corgi registered to work on the rads connected to a combination
boiler?

Robert

"RobertL" wrote in message
...
On Sep 24, 2:31 am, "Arfa Daily" wrote:
...

also, it is really true or just and urban myth that you need to be
corgi registered to work on the rads connected to a combination
boiler?

Its true if you are running the gas through the rads.
But then you will be ejected from Corgi for doing stupid dangerous things,
maybe ;-)

Is it true you have to be an electrician to work on the rads if any of the
pipes go through a part pee restricted zone?

dennis@home coughed up some electrons that declared:



"RobertL" wrote in message
...
On Sep 24, 2:31 am, "Arfa Daily" wrote:
...

also, it is really true or just and urban myth that you need to be
corgi registered to work on the rads connected to a combination
boiler?

Its true if you are running the gas through the rads.
But then you will be ejected from Corgi for doing stupid dangerous things,
maybe ;-)

Is it true you have to be an electrician to work on the rads if any of the
pipes go through a part pee restricted zone?

I've given up trying to interpret some of the legal stupidities.

What is actually important is if the plumber finds any equipotential bonding
straps, he should put them back after finishing his work. This is not to my
knowledge a notifiable work, so as long as he can do a clamp up
competently...

Technically, testing the bond is a good idea, but providing the pipes are
shiney, clean and bare and the clamps + wire go on correctly and tightly,
there's not a lot that can go wrong.

What is an interesting question is what happens if the plumber just replaced
a load of metal pipe with plastic. That's a bit more of a can of worms.

Cheers

Tim

In article
,
RobertL wrote:
also, it is really true or just and urban myth that you need to be
corgi registered to work on the rads connected to a combination
boiler?

You don't need to be CORGI registered for *any* DIY in your home.
Including gas work.

--
*If a turtle doesn't have a shell, is he homeless or naked?

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

"Tim S" wrote in message
...


What is an interesting question is what happens if the plumber just
replaced
a load of metal pipe with plastic. That's a bit more of a can of worms.

Or if they are silly enough to put PTFE tape on compression joints?

I am one of those that doesn't think taps should be earth bonded BTW.
If there isn't a path to earth its much harder to get a fatal shock than if
the plumber provides a low impedance earth.

On 24 Sep, 14:11, "dennis@home" wrote:
"Tim S" wrote in message

...

What is an interesting question is what happens if the plumber just
replaced
a load of metal pipe with plastic. That's a bit more of a can of worms.

Or if they are silly enough to put PTFE tape on compression joints?

I hadn't considered that this could cause a loss of electrical
continuity on pipe-work!
So do you mean that PTFE tape should not be used at all on compression
joints?

I would have thought that there was still enough metal-to-metal
contact in a compression joint to maitain continuity?

Mark.

wrote in message
...
On 24 Sep, 14:11, "dennis@home" wrote:
"Tim S" wrote in message

...

What is an interesting question is what happens if the plumber just
replaced
a load of metal pipe with plastic. That's a bit more of a can of worms.

Or if they are silly enough to put PTFE tape on compression joints?

I hadn't considered that this could cause a loss of electrical
continuity on pipe-work!
So do you mean that PTFE tape should not be used at all on compression
joints?

I would have thought that there was still enough metal-to-metal
contact in a compression joint to maitain continuity?

Mark.

I thought it was very bad practice to use PTFE on compression fittings. The
seal is done by the olive gripping the pipe and being located in a very
clean conical fitting. The thread has no role in sealing - so PTFE has no
role.

"dennis@home" wrote in message
...


"Tim S" wrote in message
...


What is an interesting question is what happens if the plumber just
replaced
a load of metal pipe with plastic. That's a bit more of a can of worms.

Or if they are silly enough to put PTFE tape on compression joints?


Interested to know Dennis, how PTFE tape on compression joint threads, might
compromise the integrity of earth bonding ??

Arfa

In article ,
Arfa Daily wrote:

"dennis@home" wrote in message
...


"Tim S" wrote in message
...


What is an interesting question is what happens if the plumber just
replaced a load of metal pipe with plastic. That's a bit more of a
can of worms.

Or if they are silly enough to put PTFE tape on compression joints?


Interested to know Dennis, how PTFE tape on compression joint threads,
might compromise the integrity of earth bonding ??

Those who do use PTFE on compression fittings tend to wrap it round the
olive. Not much point in putting it round the thread as this doesn't
provide any seal.

--
*Xerox and Wurlitzer will merge to market reproductive organs.

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

John wrote:
wrote in message
...
On 24 Sep, 14:11, "dennis@home"
wrote:
"Tim S" wrote in message

...

What is an interesting question is what happens if the plumber just
replaced
a load of metal pipe with plastic. That's a bit more of a can of
worms.

Or if they are silly enough to put PTFE tape on compression joints?

I hadn't considered that this could cause a loss of electrical
continuity on pipe-work!
So do you mean that PTFE tape should not be used at all on
compression joints?

I would have thought that there was still enough metal-to-metal
contact in a compression joint to maitain continuity?

Mark.

I thought it was very bad practice to use PTFE on compression
fittings. The seal is done by the olive gripping the pipe and being
located in a very clean conical fitting. The thread has no role in
sealing - so PTFE has no role.

Agreed from the sealing aspect, but its a very useful lubricant - makes
doing up the fittings easier.


--
Dave - The Medway Handyman
www.medwayhandyman.co.uk

Arfa Daily wrote:
"dennis@home" wrote in message
...


"Tim S" wrote in message
...


What is an interesting question is what happens if the plumber just
replaced
a load of metal pipe with plastic. That's a bit more of a can of
worms.

Or if they are silly enough to put PTFE tape on compression joints?


Interested to know Dennis, how PTFE tape on compression joint
threads, might compromise the integrity of earth bonding ??

Give him time, he will think of something.


--
Dave - The Medway Handyman
www.medwayhandyman.co.uk

"Arfa Daily" wrote in message
...

"dennis@home" wrote in message
...


"Tim S" wrote in message
...


What is an interesting question is what happens if the plumber just
replaced
a load of metal pipe with plastic. That's a bit more of a can of worms.

Or if they are silly enough to put PTFE tape on compression joints?


Interested to know Dennis, how PTFE tape on compression joint threads,
might compromise the integrity of earth bonding ??

I didn't say threads.
I have undone joints and found PTFE tape around the pipe and olive.

John wrote:

I thought it was very bad practice to use PTFE on compression fittings. The
seal is done by the olive gripping the pipe and being located in a very
clean conical fitting. The thread has no role in sealing - so PTFE has no
role.

There is no role in the sealing, but it does help lubricate the thread
and hence makes it easier to tighten smoothly.

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On Wed, 24 Sep 2008 07:41:31 -0700, mark.hannah wrote:

I would have thought that there was still enough metal-to-metal
contact in a compression joint to maitain continuity?

Yes, if they're done properly with PTFE over the olive rather than on the
thread of the fitting which the nut screws onto (where it is absolutely
useless since this threaded joint does not provide the seal, only
mechanical compression).

Actually neither PTFE nor any other jointing material should be necessary
on compression joints, made with unblemished pipe and new fittings in
clean conditions: it's when one's obliged to re-make joints that
something's often helpful to get it to seal, and here a couple of turns of
tape round the olive or a smidgeon of Boss White/Green/Universal
(according to application) can be used.

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

Things don't like being anthropomorphised.

dennis@home wrote:

I am one of those that doesn't think taps should be earth bonded BTW.

No such thing as "earth bonding"

If there isn't a path to earth its much harder to get a fatal shock than
if the plumber provides a low impedance earth.

ISTM you are misinterpreting the purpose of equipotential bonding:

http://wiki.diyfaq.org.uk/index.php?...tary _bonding


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On Wed, 24 Sep 2008 13:16:43 +0100, Dave Plowman (News) wrote:

You don't need to be CORGI registered for *any* DIY in your home.
Including gas work.

But, just to go over it again, you *do* have to be 'competent' (in the
words, undefined, of the Gas Safety Installation & Use Regulations).

Where one draws the line wrt non-DIY work seems to be a matter of
interpretion. IIRC in a recent article CORGI were trying to claim that
*all* connections to a boiler were the domain of registered installers.
Certainly all gas pipework and flueing is 'gas work' and there's a good
argument that hanging a boiler is too, but equally if an installer isn't
qualified to do electrics then a non-CORGI sparks may reasonably be
expected to be allowed to make electrical connections to it and do
cross-bonding if needed. Who does CH, hot and cold water and condensate
pipework then has the making of a '70s-style who-does-what dispute :-)


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

87.5% of statistics are made up

On Wed, 24 Sep 2008 02:31:37 +0100, Arfa Daily wrote:

The taps for her new bath have the large size of inlet,

3/4" BSP, standard for bath taps

but the pipes
going there are 15mm. Also, the space is very tight behind that end of
the bath, and there are also a pair of 15mm pipes tee'd in to feed an
existing shower. To make it all a lot easier to couple up, I would like
to pre-assemble the taps onto the bath, and come off them with 15mm
flexis with a push-fit remote end. Is there a flexi made, which has 15mm
push collar at one end, and 22mm tap connector at the other

You can make one (DIY - what more could you ask for? ;-))

Take a Speedfit 3/4" x 15mm tap connector and add a length of 15mm plastic
pipe (preferably polybutylene rather than PEX, for flexibility).



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

Extreme moderate

Arfa Daily wrote:

Well, today, it just got a bit
more complicated. She has now decided that she wants the radiator changing
to one of those 'ladder' types as well, so my new question is, given that
the boiler will be off by virtue of the input water and power being off, is
there anything else I need to do either before disconnecting the old
radiator, or after hooking up the new one, apart from bleeding it,
obviously? From memory, the boiler is an Alpha CB24X.

If in the unlikely case you can just swap one rad for the other - then
it would be very straight forward - turn off both rad taps, open the
coupling a little at one end and drain the rad contents into a bowl,
remove rad and replace, open taps, bleed as required[1].

However chances are you will need to alter pipework and taps for the rad
(she probably wants nice chrome ones to match the rad as well!) For this
you will need to drain some water from the system. This is exactly the
same as you would do with a conventional system except there is no
header tank and ballcock to mess about with.

Being a daughter, she has total faith in her dear old dad, but I must
confess that I am not looking forward to this job, as I have never worked on
anything other than a traditional system with indirectly heated hot water in
a storage tank, and the talk I see on here of pressurising modern systems
with footpumps and so on, puts me off a bit.

Fear not, your halo will remain intact! ;-)

(the bit about foot pumps etc is nothing to do with "normal" operation
of a sealed system but is to do with rectifying a particular type of
fault that can happen)

The taps for her new bath have the large size of inlet, but the pipes going
there are 15mm. Also, the space is very tight behind that end of the bath,
and there are also a pair of 15mm pipes tee'd in to feed an existing shower.
To make it all a lot easier to couple up, I would like to pre-assemble the
taps onto the bath, and come off them with 15mm flexis with a push-fit
remote end. Is there a flexi made, which has 15mm push collar at one end,
and 22mm tap connector at the other, or am I going to have to fit a 22mm
connector, followed by a 22 to 15 reducer ? Or is there a threaded adaptor
available ? Or what is the recommended way of getting from 22 to 15 via a
flexi tail ? All useful advice appreciated before Saturday, when it all
begins ... :-\

I take you mean something like:

http://www.screwfix.com/prods/77154/...15mm-x-x-300mm

Can't see a push fit version - but if you need that, then just put a
stub of pipe in the compression fitting and use a straight pushfit
coupling on that.


[1] See Ed's description of filling and bleeding a sealed system he

http://www.makewrite.demon.co.uk/SealedCH.html

In particular the section on "How do I refill the whole system when
working alone?"

generally easier than doing the same on a header tank system.

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

"John Rumm" wrote in message
et...
dennis@home wrote:

I am one of those that doesn't think taps should be earth bonded BTW.

No such thing as "earth bonding"

Well you can argue about the term if you want, I am sure someone will join
in if you want.


If there isn't a path to earth its much harder to get a fatal shock than
if the plumber provides a low impedance earth.

ISTM you are misinterpreting the purpose of equipotential bonding:

No I just don't like earths when there is a small chance of getting a shock
because of them.

Say a towel rail becomes live..
this indicates that there is a fault in the towel rail and that the case *is
not* connected to earth or the fuse would blow.
Now all the other stuff like pipes are connected to earth and you get a
300V+ potential between them.. nasty shock.

Of course if there were actual physical earth points on the towel radiator
rather than just the earth in the flex you might have a second earth to
connect to the pipes but that's not likely as the fuse hasn't blown.


http://wiki.diyfaq.org.uk/index.php?...tary _bonding

In article ,
YAPH wrote:
You don't need to be CORGI registered for *any* DIY in your home.
Including gas work.

But, just to go over it again, you *do* have to be 'competent' (in the
words, undefined, of the Gas Safety Installation & Use Regulations).

That's nothing to do with CORGI. Much as they might want it to be or even
imply it is.

Where one draws the line wrt non-DIY work seems to be a matter of
interpretion. IIRC in a recent article CORGI were trying to claim that
*all* connections to a boiler were the domain of registered installers.

Nothing new there. One claimed to my elderly neighbour that only they can
install a cooker. Which in her case is electric...

Certainly all gas pipework and flueing is 'gas work' and there's a good
argument that hanging a boiler is too,

Drilling some holes in a wall is gas related?

but equally if an installer isn't
qualified to do electrics then a non-CORGI sparks may reasonably be
expected to be allowed to make electrical connections to it and do
cross-bonding if needed.

If it is a new boiler supply - rather than just connecting to an existing
one - I'd hope the average CORGI wasn't let anywhere near it.

Who does CH, hot and cold water and condensate
pipework then has the making of a '70s-style who-does-what dispute :-)

As regards DIY, no dispute. Just ignore all these greedy people trying to
feather their nest.

--
*Everyone has a photographic memory. Some just don't have film*

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

In message , YAPH
writes
On Wed, 24 Sep 2008 13:16:43 +0100, Dave Plowman (News) wrote:

You don't need to be CORGI registered for *any* DIY in your home.
Including gas work.

But, just to go over it again, you *do* have to be 'competent' (in the
words, undefined, of the Gas Safety Installation & Use Regulations).

That should exclude a fair number of CORGIs

CORGI is only concerned with safety, not competence,


Where one draws the line wrt non-DIY work seems to be a matter of
interpretion. IIRC in a recent article CORGI were trying to claim that
*all* connections to a boiler were the domain of registered installers.

Aren't CORGI losing registration to Centrica ?

Certainly all gas pipework and flueing is 'gas work' and there's a good
argument that hanging a boiler is too, but equally if an installer isn't
qualified to do electrics then a non-CORGI sparks may reasonably be
expected to be allowed to make electrical connections to it and do
cross-bonding if needed. Who does CH, hot and cold water and condensate
pipework then has the making of a '70s-style who-does-what dispute :-)

This is a DIY group for people who DIY

Like me

--
geoff

dennis@home wrote:

"John Rumm" wrote in message
et...
dennis@home wrote:

I am one of those that doesn't think taps should be earth bonded BTW.

No such thing as "earth bonding"

Well you can argue about the term if you want, I am sure someone will
join in if you want.

The difficulty with the term (aside from it having no real meaning) is
that is introduces confusion. Earthing and equipotential bonding are two
unrelated concepts that reduce shock hazards in different ways.

If there isn't a path to earth its much harder to get a fatal shock
than if the plumber provides a low impedance earth.

ISTM you are misinterpreting the purpose of equipotential bonding:

No I just don't like earths when there is a small chance of getting a
shock because of them.

Again, who mentioned earths? There is no requirement for supplementary
bonding to be earthed.

Say a towel rail becomes live..
this indicates that there is a fault in the towel rail and that the case
*is not* connected to earth or the fuse would blow.

Indeed. The (presumably electric in this case) towel rail's heating
element should be earthed to ensure the supply is disconnected in the
event of a fault.

Now all the other stuff like pipes are connected to earth and you get a
300V+ potential between them.. nasty shock.

Which is where the equipotential zone comes into play - eliminating (or
at least reducing to a safe level) any potential difference should the
fault not be cleared by other means.

Of course if there were actual physical earth points on the towel
radiator rather than just the earth in the flex you might have a second
earth to connect to the pipes but that's not likely as the fuse hasn't
blown.

If the pipes are capable of introducing a potential into the zone, they
should also be bonded.



--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

Dave Plowman (News) wrote:

Certainly all gas pipework and flueing is 'gas work' and there's a good
argument that hanging a boiler is too,

Drilling some holes in a wall is gas related?

Drilling the holes is not, but what you stick through them (and how you
do it) might be! ;-)


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

"John Rumm" wrote in message
et...
Arfa Daily wrote:

Well, today, it just got a bit more complicated. She has now decided that
she wants the radiator changing to one of those 'ladder' types as well,
so my new question is, given that the boiler will be off by virtue of the
input water and power being off, is there anything else I need to do
either before disconnecting the old radiator, or after hooking up the new
one, apart from bleeding it, obviously? From memory, the boiler is an
Alpha CB24X.

If in the unlikely case you can just swap one rad for the other - then it
would be very straight forward - turn off both rad taps, open the coupling
a little at one end and drain the rad contents into a bowl, remove rad and
replace, open taps, bleed as required[1].

However chances are you will need to alter pipework and taps for the rad
(she probably wants nice chrome ones to match the rad as well!) For this
you will need to drain some water from the system. This is exactly the
same as you would do with a conventional system except there is no header
tank and ballcock to mess about with.

Being a daughter, she has total faith in her dear old dad, but I must
confess that I am not looking forward to this job, as I have never worked
on anything other than a traditional system with indirectly heated hot
water in a storage tank, and the talk I see on here of pressurising
modern systems with footpumps and so on, puts me off a bit.

Fear not, your halo will remain intact! ;-)

(the bit about foot pumps etc is nothing to do with "normal" operation of
a sealed system but is to do with rectifying a particular type of fault
that can happen)

The taps for her new bath have the large size of inlet, but the pipes
going there are 15mm. Also, the space is very tight behind that end of
the bath, and there are also a pair of 15mm pipes tee'd in to feed an
existing shower. To make it all a lot easier to couple up, I would like
to pre-assemble the taps onto the bath, and come off them with 15mm
flexis with a push-fit remote end. Is there a flexi made, which has 15mm
push collar at one end, and 22mm tap connector at the other, or am I
going to have to fit a 22mm connector, followed by a 22 to 15 reducer ?
Or is there a threaded adaptor available ? Or what is the recommended way
of getting from 22 to 15 via a flexi tail ? All useful advice appreciated
before Saturday, when it all begins ... :-\

I take you mean something like:

http://www.screwfix.com/prods/77154/...15mm-x-x-300mm

Can't see a push fit version - but if you need that, then just put a stub
of pipe in the compression fitting and use a straight pushfit coupling on
that.


[1] See Ed's description of filling and bleeding a sealed system he

http://www.makewrite.demon.co.uk/SealedCH.html

In particular the section on "How do I refill the whole system when
working alone?"

generally easier than doing the same on a header tank system.

--
Cheers,

John.

Thanks for the good advice, and confidence that it will be a straightforward
job for me ! Son in law went to B&Q today, and got a pair of flexis that he
tells me fit the taps directly at one end, and are 15mm push fit at t'other.
Believe it or not, he says a spotty-faced erk in a B&Q teeshirt found these
for him ...

All ok on the rad. The pipework will definitely need modding, so I guess a
degree of draining down will be needed. Presumably, as it's an upstairs rad,
so at the top of the system, if I shut off any other upstairs rads so that
they cannot drain back into the upstairs pipework, then not much water will
need to be removed ?
Arfa

In article ,
Arfa Daily wrote:
All ok on the rad. The pipework will definitely need modding, so I guess
a degree of draining down will be needed. Presumably, as it's an
upstairs rad, so at the top of the system, if I shut off any other
upstairs rads so that they cannot drain back into the upstairs
pipework, then not much water will need to be removed ?

If you're not sure of the condition, a full drain down and flush followed
by new inhibitor will do no harm.

If draining down is difficult, now is the time to fit one of those
combination lockshield valves and drain at a convenient rad - ie one close
to an outside door.

--
*Why doesn't Tarzan have a beard? *

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

On Wed, 24 Sep 2008 23:58:44 +0100, Dave Plowman (News) wrote:

In article ,
YAPH wrote:

But, just to go over it again, you *do* have to be 'competent' (in the
words, undefined, of the Gas Safety Installation & Use Regulations).

That's nothing to do with CORGI. Much as they might want it to be or
even imply it is.

And even in a professional context soon won't be: I'm sure anyone who
thinks CORGI are bad is going to *love* Capita.



Drilling some holes in a wall is gas related?

If they're the difference between holding up a gas appliance and it
falling off the wall, yes.


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

Women always generalise

In article ,
YAPH wrote:
On Wed, 24 Sep 2008 23:58:44 +0100, Dave Plowman (News) wrote:

Drilling some holes in a wall is gas related?

If they're the difference between holding up a gas appliance and it
falling off the wall, yes.

I'd say the average DIYer who feels competent to fit a new boiler is
likely to be more careful about fixings than the average CORGI.

It would be wonderful if CORGI membership was some guarantee of good
workmanship. Unfortunately, it's not. Very few of these sort of trade
bodies are - they're more concerned about their income from fees than
maintaining any standards.

--
*I must always remember that I'm unique, just like everyone else. *

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

YAPH wrote:
On Wed, 24 Sep 2008 23:58:44 +0100, Dave Plowman (News) wrote:

In article ,
YAPH wrote:

But, just to go over it again, you *do* have to be 'competent' (in the
words, undefined, of the Gas Safety Installation & Use Regulations).
That's nothing to do with CORGI. Much as they might want it to be or
even imply it is.

And even in a professional context soon won't be: I'm sure anyone who
thinks CORGI are bad is going to *love* Capita.

Yup, from the folks who brought us TV Licensing IIRC!



--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On Thu, 25 Sep 2008 16:36:51 +0100, Dave Plowman (News) wrote:

It would be wonderful if CORGI membership was some guarantee of good
workmanship. Unfortunately, it's not. Very few of these sort of trade
bodies are - they're more concerned about their income from fees than
maintaining any standards.

What sort of trade bodies are you talking about? In the 'trade' (rather
than 'profession') arena I can think of CORGI and maybe FENSA who are
absolutely necessary for the tradesperson to purue their livelihood. With
NIC/IEC there are alternatives (NAPIT, EIA). IPHE (or whatever they're
called this month) is optional. I'm not even considering shop-window
bodies like FMB.

I don't know how many useless members FENSA chuck out, but CORGI have a
regular roll of dishonour of installers who they've deregistered for one
reason or another.

Of course the threat of deregistration doesn't make a useless installer
competent, but it does focus one's mind on doing the right thing when one
might be tempted to cut corners.


--
John Stumbles

My karma ran over my dogma

On Thu, 25 Sep 2008 10:06:07 +0100, Dave Plowman (News) wrote:

If draining down is difficult, now is the time to fit one of those
combination lockshield valves and drain at a convenient rad - ie one close
to an outside door.

But one with the drain-off *outboard* of the valve - the ones with the
drian between the valve and the rad are not a straight swap for the
non-drain-off types.

--
John Stumbles

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

In article ,
John Stumbles wrote:
If draining down is difficult, now is the time to fit one of those
combination lockshield valves and drain at a convenient rad - ie one
close to an outside door.

But one with the drain-off *outboard* of the valve - the ones with the
drian between the valve and the rad are not a straight swap for the
non-drain-off types.

Didn't even realise there were two types. The one I've got was a straight
swop. It came from Screwfix.

--
Small asylum seeker wanted as mud flap, must be flexible and willing to travel

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

dennis@home wrote:

"John Rumm" wrote
No such thing as "earth bonding"

Well you can argue about the term if you want, I am sure someone will
join in if you want.

John's absolutely correct and, to add to what he's already said,
earthing and bonding should be thought of as quite separate concepts:

- earthing (of Class 1 equipment) is an /active/ protection measure that
works by automatically disconnecting the supply to the faulty equipment;

- an alternative to earthing is the use of Class 2 ('double' insulated)
equipment which is constructed such that the chance of exposed metal
parts is close to zero. (The wiring regulations still require an earth
to be available in a circuit feeding a Class 2 appliance, so that it can
safely be replaced by Class 1 equipment.)

- Equipotential bonding is a /passive/ protection measure which prevents
dangerous 'touch voltages' appearing between different items simply by
connecting them together with low-resistance conductors of a size that
won't overheat or rupture for any current reasonably likely to flow.

No I just don't like earths when there is a small chance of getting a
shock because of them.

Things like water taps on plastic pipework (even with copper tails) are
not going to become live on their own - so they don't need to be bonded.
In the language of the wiring regs they are not
extraneous-conductive-parts because they don't import a potential from
outside the location.

Say a towel rail becomes live..
this indicates that there is a fault in the towel rail and that the case
*is not* connected to earth or the fuse would blow.

This is a good example, an open-circuit circuit earth (CPC) being a
fairly common fault.

Now all the other stuff like pipes are connected to earth and you get a
300V+ potential between them.. nasty shock.

With supplementary bonding in place there can be no significant touch
voltage, whether or not anything blows or trips. If the bonding
provides another path to earth, as it often will, the chances are that
the overcurrent protection or RCD will operate as normal and isolate the
fault. If the bonding is otherwise floating then you may end up with
230 volts on everything. With correctly done bonding there should be no
risk of a fatal or serious shock, but people are likely to feel tingles
when touching metal items and this will hopefully eventually lead to the
fault being diagnosed.

Under the 17th edition regs the supplementary bonding can be omitted,
but only if the main bonding is OK and all circuits feeding the bathroom
are 30 mA RCD protected. In this case there is the potential (no pun
....) for a serious shock between the live towel rail and other (earthy)
metalwork. However if the shock current is large enough to be really
dangerous the RCD will trip and cut off the supply within a few
milliseconds.

Of course if there were actual physical earth points on the towel
radiator rather than just the earth in the flex you might have a second
earth to connect to the pipes but that's not likely as the fuse hasn't
blown.

The regs allow the flex to be used as part of the bonding (you bond in
the fused connection unit). Clearly the committee considered that the
risk of an open circuit in the flex was low enough not to worry about.
If you disagree there's nothing to stop you bonding to the rail itself.

--
Andy

In an earlier contribution to this discussion,
Dave Plowman (News) wrote:

In article ,
John Stumbles wrote:

Buy one with the drain-off *outboard* of the valve - the ones with
the drian between the valve and the rad are not a straight swap for
the non-drain-off types.

Didn't even realise there were two types. The one I've got was a
straight swop. It came from Screwfix.

There are more than two types. There is the type referred to above
http://tinyurl.com/4juks4, where the drain-off in in the tail - between the
rad and valve - which increases the offset of the supply type. These may be
impossible to fit to some rads where the threaded hole is inboard since the
drain outlet may foul the rad as you screw it in.

Then there's the Screwfix type http://tinyurl.com/5y9z44 - which have a
fairly conventional drain-off fitting at the end, with the spout pointing
downwards and a square bit to turn on the end. These can suffer from the
same problem as other drain elbows etc. - where the washer sticks, so
nothing comes out when you unscrew the end.

Finally, there's what I consider to be the best sort
http://tinyurl.com/4mzxtx - which have the drain plug *inside* the
sideways-facing drain spout. You can unscrew and remove the whole plug (no
washer sticking opportunities) with both radiator valves closed, and very
little will come out until you open the radiator's bleed screw to let some
air in. You control the flow with the bleed screw.

With all 3 sorts, with both valves closed, just the radiator is drained -
but the pipework can also be drained by opening the valves.
--
Cheers,
Roger
______
Email address maintained for newsgroup use only, and not regularly
monitored.. Messages sent to it may not be read for several weeks.
PLEASE REPLY TO NEWSGROUP!

"Andy Wade" wrote in message
...
dennis@home wrote:

"John Rumm" wrote
No such thing as "earth bonding"

Well you can argue about the term if you want, I am sure someone will
join in if you want.

John's absolutely correct and, to add to what he's already said, earthing
and bonding should be thought of as quite separate concepts:

But not in a normal house, using normal appliances as they metal case will
always be bonded to earth.


- earthing (of Class 1 equipment) is an /active/ protection measure that
works by automatically disconnecting the supply to the faulty equipment;

- an alternative to earthing is the use of Class 2 ('double' insulated)
equipment which is constructed such that the chance of exposed metal parts
is close to zero. (The wiring regulations still require an earth to be
available in a circuit feeding a Class 2 appliance, so that it can safely
be replaced by Class 1 equipment.)

- Equipotential bonding is a /passive/ protection measure which prevents
dangerous 'touch voltages' appearing between different items simply by
connecting them together with low-resistance conductors of a size that
won't overheat or rupture for any current reasonably likely to flow.

No I just don't like earths when there is a small chance of getting a
shock because of them.

Things like water taps on plastic pipework (even with copper tails) are
not going to become live on their own - so they don't need to be bonded.
In the language of the wiring regs they are not
extraneous-conductive-parts because they don't import a potential from
outside the location.

Say a towel rail becomes live..
this indicates that there is a fault in the towel rail and that the case
*is not* connected to earth or the fuse would blow.

This is a good example, an open-circuit circuit earth (CPC) being a fairly
common fault.

Its actually two faults, the earth has been disconnected and the live
insulation has failed, not actually very common.


Now all the other stuff like pipes are connected to earth and you get a
300V+ potential between them.. nasty shock.

With supplementary bonding in place there can be no significant touch
voltage, whether or not anything blows or trips. If the bonding provides
another path to earth, as it often will, the chances are that the
overcurrent protection or RCD will operate as normal and isolate the
fault. If the bonding is otherwise floating then you may end up with 230
volts on everything. With correctly done bonding there should be no risk
of a fatal or serious shock, but people are likely to feel tingles when
touching metal items and this will hopefully eventually lead to the fault
being diagnosed.

As I said unless you are going to modify the appliance you are bonding to
earth.


Under the 17th edition regs the supplementary bonding can be omitted, but
only if the main bonding is OK and all circuits feeding the bathroom are
30 mA RCD protected. In this case there is the potential (no pun ...) for
a serious shock between the live towel rail and other (earthy) metalwork.
However if the shock current is large enough to be really dangerous the
RCD will trip and cut off the supply within a few milliseconds.

That would be the main bonding to where exactly?


Of course if there were actual physical earth points on the towel
radiator rather than just the earth in the flex you might have a second
earth to connect to the pipes but that's not likely as the fuse hasn't
blown.

The regs allow the flex to be used as part of the bonding (you bond in the
fused connection unit). Clearly the committee considered that the risk of
an open circuit in the flex was low enough not to worry about. If you
disagree there's nothing to stop you bonding to the rail itself.

So where do you not bond to earth within the FCU?

Like I said for domestic wiring it is bonding to earth, there is very little
alternative if you have any sort of appliance.

And as I said if you want to discuss bonding in an industrial context it can
be done.

We bonded huge amounts of metal together but we didn't use green and yellow
earth cable to do it as it wasn't earth.

"John Rumm" wrote in message
et...
dennis@home wrote:

I am one of those that doesn't think taps should be earth bonded BTW.

No such thing as "earth bonding"

If there isn't a path to earth its much harder to get a fatal shock than
if the plumber provides a low impedance earth.

ISTM you are misinterpreting the purpose of equipotential bonding:

http://wiki.diyfaq.org.uk/index.php?...tary _bonding


"What it does is electrically tie together all accessible conductive parts
(pipes, taps, electrical appliances etc) that could under fault conditions
introduce a dangerous potential into the room. "

A rank amateur would look at that and not know what potential is.
"Potential" needs a explanation at this point.

In an earlier contribution to this discussion,
Doctor Drivel wrote:


"What it does is electrically tie together all accessible conductive
parts (pipes, taps, electrical appliances etc) that could under fault
conditions introduce a dangerous potential into the room. "

A rank amateur would look at that and not know what potential is.
"Potential" needs a explanation at this point.

Anyone who doesn't understand the word "potential" in relation to
electricity shouldn't go anywhere *near* mains house-wiring!
--
Cheers,
Roger
______
Email address maintained for newsgroup use only, and not regularly
monitored.. Messages sent to it may not be read for several weeks.
PLEASE REPLY TO NEWSGROUP!