Today I had a flood in the bathroom. A compression joint connecting the
copper pipe work to a short length of plastic pipe to the digital shower
mixer failed and being at mains pressure produced a spectacular fountain.

This joint was made mid December and has been fine ever since. The reason
for the short plastic pipe was due to the pipe clips I was using meant if I
went copper up to the push fit connectors Mira have specified it would have
resulted in an awkward little off-set so the plastic pipe solved that. I
have been scratching my head as to the cause why after 21/2 months?

At first I thought I may have omitted the insert but it was there, I did
note the olive did not seem to have bitten into the plastic as expected so
there maybe the nut had not been fully tightened, but that usually results
in a weeping join.

I am a bit old school in that I prefer copper and soldered joins and
compression fittings as necessary and have never felt 100% confident in
plastic and push fit joins other than for low pressure waste pipe
applications. Today’s experience has not improved my feelings about plastic
pipe in mains pressure applications. It has left me wondering if it was
more an external issue namely a temporary spike in water pressure and it
just found the weakest point?

Anyway, I cannot say I feel confident in the repair and domestic management
was not best pleased with the soaked towels and bedding, especially with
the stuff she had ironed only a couple of hours before.

Any opinions on the cause and suggested remedies would be appreciated.

On 25 Feb 2024 at 00:45:48 GMT, Tricky Dicky wrote:

>
> Today I had a flood in the bathroom. A compression joint connecting the
> copper pipe work to a short length of plastic pipe to the digital shower
> mixer failed and being at mains pressure produced a spectacular fountain.
>
> This joint was made mid December and has been fine ever since. The reason
> for the short plastic pipe was due to the pipe clips I was using meant if I
> went copper up to the push fit connectors Mira have specified it would have
> resulted in an awkward little off-set so the plastic pipe solved that. I
> have been scratching my head as to the cause why after 21/2 months?
>
> At first I thought I may have omitted the insert but it was there, I did
> note the olive did not seem to have bitten into the plastic as expected so
> there maybe the nut had not been fully tightened, but that usually results
> in a weeping join.
>
> I am a bit old school in that I prefer copper and soldered joins and
> compression fittings as necessary and have never felt 100% confident in
> plastic and push fit joins other than for low pressure waste pipe
> applications. Today’s experience has not improved my feelings about plastic
> pipe in mains pressure applications. It has left me wondering if it was
> more an external issue namely a temporary spike in water pressure and it
> just found the weakest point?
>
> Anyway, I cannot say I feel confident in the repair and domestic management
> was not best pleased with the soaked towels and bedding, especially with
> the stuff she had ironed only a couple of hours before.
>
> Any opinions on the cause and suggested remedies would be appreciated.

Not sure of the cause - overtightened compression fitting maybe? I'd try a
pushfit plastic connector - I've done a fair few plastic-copper connections
using them.
--
Cheers, Rob, Sheffield UK

On 25/02/2024 00:45, Tricky Dicky wrote:
>
> Today I had a flood in the bathroom. A compression joint connecting the
> copper pipe work to a short length of plastic pipe to the digital shower
> mixer failed and being at mains pressure produced a spectacular fountain.
>
> This joint was made mid December and has been fine ever since. The reason
> for the short plastic pipe was due to the pipe clips I was using meant if I
> went copper up to the push fit connectors Mira have specified it would have
> resulted in an awkward little off-set so the plastic pipe solved that. I
> have been scratching my head as to the cause why after 21/2 months?
>
> At first I thought I may have omitted the insert but it was there, I did
> note the olive did not seem to have bitten into the plastic as expected so
> there maybe the nut had not been fully tightened, but that usually results
> in a weeping join.

Not tight enough would be my guess... The rubber seals on the insert
will keep it watertight with relatively little compression force, but
inadequate tightening allows scope for the pipe to slowly be pushed out
of the joint by water hammer and other pressure fluctuations.

> I am a bit old school in that I prefer copper and soldered joins and
> compression fittings as necessary and have never felt 100% confident in
> plastic and push fit joins other than for low pressure waste pipe
> applications. Today’s experience has not improved my feelings about plastic
> pipe in mains pressure applications. It has left me wondering if it was
> more an external issue namely a temporary spike in water pressure and it
> just found the weakest point?

To be fair I have never had a problem with plastic, although for plastic
to copper joints I would normally use a pushfit fitting. (probably
because I keep a sizeable stock of end feed, a handful of pushfit, and
fairly few compression fittings.

> Anyway, I cannot say I feel confident in the repair and domestic management
> was not best pleased with the soaked towels and bedding, especially with
> the stuff she had ironed only a couple of hours before.
>
> Any opinions on the cause and suggested remedies would be appreciated.

Torque up the compression a bit more... or use copper and put a small
offset "set" in the pipe with a pipe bender.

--
Cheers,

John.

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

Perhaps the main water is higher, mine varies quite a bit.

Tricky Dicky <tricky.dicky@sky.com> wrote:
>
> Today I had a flood in the bathroom. A compression joint connecting the
> copper pipe work to a short length of plastic pipe to the digital shower
> mixer failed and being at mains pressure produced a spectacular fountain.
>
> This joint was made mid December and has been fine ever since. The reason
> for the short plastic pipe was due to the pipe clips I was using meant if I
> went copper up to the push fit connectors Mira have specified it would have
> resulted in an awkward little off-set so the plastic pipe solved that. I
> have been scratching my head as to the cause why after 21/2 months?
>
> At first I thought I may have omitted the insert but it was there, I did
> note the olive did not seem to have bitten into the plastic as expected so
> there maybe the nut had not been fully tightened, but that usually results
> in a weeping join.
>
> I am a bit old school in that I prefer copper and soldered joins and
> compression fittings as necessary and have never felt 100% confident in
> plastic and push fit joins other than for low pressure waste pipe
> applications. Today’s experience has not improved my feelings about plastic
> pipe in mains pressure applications. It has left me wondering if it was
> more an external issue namely a temporary spike in water pressure and it
> just found the weakest point?
>
> Anyway, I cannot say I feel confident in the repair and domestic management
> was not best pleased with the soaked towels and bedding, especially with
> the stuff she had ironed only a couple of hours before.
>
> Any opinions on the cause and suggested remedies would be appreciated.
>
>

You mention a “digital” shower mixer. Does it use a solenoid to shut the
water off? Just wondering if the abrupt nature of the shut off could be a
factor?

Tim

--
Please don't feed the trolls

On 25/02/2024 01:12, RJH wrote:
> On 25 Feb 2024 at 00:45:48 GMT, Tricky Dicky wrote:
>
>>
>> Today I had a flood in the bathroom. A compression joint connecting the
>> copper pipe work to a short length of plastic pipe to the digital shower
>> mixer failed and being at mains pressure produced a spectacular fountain.
>>
>> This joint was made mid December and has been fine ever since. The reason
>> for the short plastic pipe was due to the pipe clips I was using meant if I
>> went copper up to the push fit connectors Mira have specified it would have
>> resulted in an awkward little off-set so the plastic pipe solved that. I
>> have been scratching my head as to the cause why after 21/2 months?
>>
>> At first I thought I may have omitted the insert but it was there, I did
>> note the olive did not seem to have bitten into the plastic as expected so
>> there maybe the nut had not been fully tightened, but that usually results
>> in a weeping join.
>>
>> I am a bit old school in that I prefer copper and soldered joins and
>> compression fittings as necessary and have never felt 100% confident in
>> plastic and push fit joins other than for low pressure waste pipe
>> applications. Today’s experience has not improved my feelings about plastic
>> pipe in mains pressure applications. It has left me wondering if it was
>> more an external issue namely a temporary spike in water pressure and it
>> just found the weakest point?
>>
>> Anyway, I cannot say I feel confident in the repair and domestic management
>> was not best pleased with the soaked towels and bedding, especially with
>> the stuff she had ironed only a couple of hours before.
>>
>> Any opinions on the cause and suggested remedies would be appreciated.
>
> Not sure of the cause - overtightened compression fitting maybe? I'd try a
> pushfit plastic connector - I've done a fair few plastic-copper connections
> using them.

did you put a pipe stiffener at *each* end of the plastic pipe?

And another cause can be incorrect pipe insertion depth into the
fitting, some plastic pipe have a repeating black line on the outside of
the pipe, the idea being you cut at one of the black lines, and then put
pipe stiffener on, then insert into fitting until you reach the 2nd
black line on the pipe......

And as others have said, not screwing up the plastic pipe fitting up
tight enough. if the pipe is loose, then water hammer will flex the pipe
and those knife blades will cut grooves and work its wat to the end of
the pipe with each successive water hammer session.

Also clipping down the water pipe will reduce the effect of pipe
movement due to water hammer.

S.

On 25/02/2024 00:45, Tricky Dicky wrote:
>
> Today I had a flood in the bathroom. A compression joint connecting the
> copper pipe work to a short length of plastic pipe to the digital shower
> mixer failed and being at mains pressure produced a spectacular fountain.
>
> This joint was made mid December and has been fine ever since. The reason
> for the short plastic pipe was due to the pipe clips I was using meant if I
> went copper up to the push fit connectors Mira have specified it would have
> resulted in an awkward little off-set so the plastic pipe solved that. I
> have been scratching my head as to the cause why after 21/2 months?
>
> At first I thought I may have omitted the insert but it was there, I did
> note the olive did not seem to have bitten into the plastic as expected so
> there maybe the nut had not been fully tightened, but that usually results
> in a weeping join.
>
> I am a bit old school in that I prefer copper and soldered joins and
> compression fittings as necessary and have never felt 100% confident in
> plastic and push fit joins other than for low pressure waste pipe
> applications. Today’s experience has not improved my feelings about plastic
> pipe in mains pressure applications. It has left me wondering if it was
> more an external issue namely a temporary spike in water pressure and it
> just found the weakest point?
>
> Anyway, I cannot say I feel confident in the repair and domestic management
> was not best pleased with the soaked towels and bedding, especially with
> the stuff she had ironed only a couple of hours before.
>
> Any opinions on the cause and suggested remedies would be appreciated.
>
A long time ago (18 years?) I had a near disaster when a 22mm plastic
pipe came out of a compression elbow, fortunately the SWMBO at the time
happened to come home very soon after it happened and turned the water
off before there was much damage. I decided it was probably caused by
thermal expansion on a long pipe run trying to move the elbow and the
short run on the other side of the elbow preventing it from moving ...
resulting in the pipe walking out of the fitting. I replaced the
compression elbow with pushfit, restrained the pipe, and allowed the
short run to move.
I realise that your problem was on a cold pipe, but perhaps repeated
hydraulic shock, from the solenoid shutting-off or from general water
hammer, pushed the pipe out. I always use pushfit for plastic-copper
transition.

On 25/02/2024 08:57, SH wrote:
> On 25/02/2024 01:12, RJH wrote:
>> On 25 Feb 2024 at 00:45:48 GMT, Tricky  Dicky wrote:
>>
>>>
>>> Today I had a flood in the bathroom. A compression joint connecting the
>>> copper pipe work to a short length of plastic pipe to the digital shower
>>> mixer failed and being at mains pressure produced a spectacular
>>> fountain.
>>>
>>> This joint was made mid December and has been fine ever since. The
>>> reason
>>> for the short plastic pipe was due to the pipe clips I was using
>>> meant if I
>>> went copper up to the push fit connectors Mira have specified it
>>> would have
>>> resulted in an awkward little off-set so the plastic pipe solved that. I
>>> have been scratching my head as to the cause why after 21/2 months?
>>>
>>> At first I thought I may have omitted the insert but it was there, I did
>>> note the olive did not seem to have bitten into the plastic as
>>> expected so
>>> there maybe the nut had not been fully tightened, but that usually
>>> results
>>> in a weeping join.
>>>
>>> I am a bit old school in that I prefer copper and soldered joins and
>>> compression fittings as necessary and have never felt 100% confident in
>>> plastic and push fit joins other than for low pressure waste pipe
>>> applications. Today’s experience has not improved my feelings about
>>> plastic
>>> pipe in mains pressure applications. It has left me wondering if it was
>>> more an external issue namely a temporary spike in water pressure and it
>>> just found the weakest point?
>>>
>>> Anyway, I cannot say I feel confident in the repair and domestic
>>> management
>>> was not best pleased with the soaked towels and bedding, especially with
>>> the stuff she had ironed only a couple of hours before.
>>>
>>> Any opinions on the cause and suggested remedies would be appreciated.
>>
>> Not sure of the cause - overtightened compression fitting maybe? I'd
>> try a
>> pushfit plastic connector - I've done a fair few plastic-copper
>> connections
>> using them.
>
>
> did you put a pipe stiffener at *each* end of the plastic pipe?
>
> And another cause can be incorrect pipe insertion depth into the
> fitting, some plastic pipe have a repeating black line on the outside of
> the pipe, the idea being you cut at one of the black lines, and then put
> pipe stiffener on, then insert into fitting until you reach the 2nd
> black line on the pipe......

I get the impression you might be assuming the fitting was push fit? The
OP said it was a compression fitting that failed on the plastic pipe.

The insertion depth marks may not be correct for a compression fitting -
or even consistent between brands.

--
Cheers,

John.

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

Tricky Dicky <tricky.dicky@sky.com> wrote:
>
> Today I had a flood in the bathroom. A compression joint connecting the
> copper pipe work to a short length of plastic pipe to the digital shower
> mixer failed and being at mains pressure produced a spectacular fountain.
>
> This joint was made mid December and has been fine ever since. The reason
> for the short plastic pipe was due to the pipe clips I was using meant if I
> went copper up to the push fit connectors Mira have specified it would have
> resulted in an awkward little off-set so the plastic pipe solved that. I
> have been scratching my head as to the cause why after 21/2 months?
>
> At first I thought I may have omitted the insert but it was there, I did
> note the olive did not seem to have bitten into the plastic as expected so
> there maybe the nut had not been fully tightened, but that usually results
> in a weeping join.
>
> I am a bit old school in that I prefer copper and soldered joins and
> compression fittings as necessary and have never felt 100% confident in
> plastic and push fit joins other than for low pressure waste pipe
> applications. Today’s experience has not improved my feelings about plastic
> pipe in mains pressure applications. It has left me wondering if it was
> more an external issue namely a temporary spike in water pressure and it
> just found the weakest point?
>
> Anyway, I cannot say I feel confident in the repair and domestic management
> was not best pleased with the soaked towels and bedding, especially with
> the stuff she had ironed only a couple of hours before.
>
> Any opinions on the cause and suggested remedies would be appreciated.
>
>

As a few have said it must have been an under tightened nut as the olive
just slid off whereas previous compression joints to plastic have resulted
in secure olives that could not be removed. It just puzzled me that there
had been no weeping which is a common indication of an under tightened nut
or that it did not come apart on first pressurisation as we have quite
considerable pressure on the mains.

Anyway SWAMBO has calmed down and the heat pump tumble dryer has been
working overtime and stuff is going back in the airing cupboard. We are now
worrying if it will happen again, I might put a pencil mark on the pipe and
regularly observe it to see if any movement occurs.

Thanks for all the replies.

On 25/02/2024 14:35, Tricky Dicky wrote:
> Tricky Dicky <tricky.dicky@sky.com> wrote:
>>
>> Today I had a flood in the bathroom. A compression joint connecting the
>> copper pipe work to a short length of plastic pipe to the digital shower
>> mixer failed and being at mains pressure produced a spectacular fountain.
>>
>> This joint was made mid December and has been fine ever since. The reason
>> for the short plastic pipe was due to the pipe clips I was using meant if I
>> went copper up to the push fit connectors Mira have specified it would have
>> resulted in an awkward little off-set so the plastic pipe solved that. I
>> have been scratching my head as to the cause why after 21/2 months?
>>
>> At first I thought I may have omitted the insert but it was there, I did
>> note the olive did not seem to have bitten into the plastic as expected so
>> there maybe the nut had not been fully tightened, but that usually results
>> in a weeping join.
>>
>> I am a bit old school in that I prefer copper and soldered joins and
>> compression fittings as necessary and have never felt 100% confident in
>> plastic and push fit joins other than for low pressure waste pipe
>> applications. Today’s experience has not improved my feelings about plastic
>> pipe in mains pressure applications. It has left me wondering if it was
>> more an external issue namely a temporary spike in water pressure and it
>> just found the weakest point?
>>
>> Anyway, I cannot say I feel confident in the repair and domestic management
>> was not best pleased with the soaked towels and bedding, especially with
>> the stuff she had ironed only a couple of hours before.
>>
>> Any opinions on the cause and suggested remedies would be appreciated.
>>
>>
>
> As a few have said it must have been an under tightened nut as the olive
> just slid off whereas previous compression joints to plastic have resulted
> in secure olives that could not be removed. It just puzzled me that there
> had been no weeping which is a common indication of an under tightened nut
> or that it did not come apart on first pressurisation as we have quite
> considerable pressure on the mains.

What inserts were you using? The speedfit ones I normally use[1] have
several O rings on them to seal in the bore of the pipe and also in the
bore of the fitting. The olive is not really required to make the joint
water tight in this case - it just needs to grip the pipe well enough to
stop it being pulled out.

[1] https://wiki.diyfaq.org.uk/index.php/File:InsertForPlasticPipe.jpg

(and two more rings on the stem of the insert that seal on the inside of
the pipe bore)

>
> Anyway SWAMBO has calmed down and the heat pump tumble dryer has been
> working overtime and stuff is going back in the airing cupboard. We are now
> worrying if it will happen again, I might put a pencil mark on the pipe and
> regularly observe it to see if any movement occurs.
Probably not a bad idea for peace of mind...

Failing that make up a compression to plastic fitting on the bench, then
take it apart and work out how much tightening you need to properly
deform the olive enough to bit into the pipe.

--
Cheers,

John.

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

On 25/02/2024 14:35, Tricky Dicky wrote:
> Tricky Dicky <tricky.dicky@sky.com> wrote:
>>
>> Today I had a flood in the bathroom. A compression joint connecting the
>> copper pipe work to a short length of plastic pipe to the digital shower
>> mixer failed and being at mains pressure produced a spectacular fountain.
>>
>> This joint was made mid December and has been fine ever since. The reason
>> for the short plastic pipe was due to the pipe clips I was using meant if I
>> went copper up to the push fit connectors Mira have specified it would have
>> resulted in an awkward little off-set so the plastic pipe solved that. I
>> have been scratching my head as to the cause why after 21/2 months?
>>
>> At first I thought I may have omitted the insert but it was there, I did
>> note the olive did not seem to have bitten into the plastic as expected so
>> there maybe the nut had not been fully tightened, but that usually results
>> in a weeping join.
>>
>> I am a bit old school in that I prefer copper and soldered joins and
>> compression fittings as necessary and have never felt 100% confident in
>> plastic and push fit joins other than for low pressure waste pipe
>> applications. Today’s experience has not improved my feelings about plastic
>> pipe in mains pressure applications. It has left me wondering if it was
>> more an external issue namely a temporary spike in water pressure and it
>> just found the weakest point?
>>
>> Anyway, I cannot say I feel confident in the repair and domestic management
>> was not best pleased with the soaked towels and bedding, especially with
>> the stuff she had ironed only a couple of hours before.
>>
>> Any opinions on the cause and suggested remedies would be appreciated.
>>
>>
>
> As a few have said it must have been an under tightened nut as the olive
> just slid off whereas previous compression joints to plastic have resulted
> in secure olives that could not be removed. It just puzzled me that there
> had been no weeping which is a common indication of an under tightened nut
> or that it did not come apart on first pressurisation as we have quite
> considerable pressure on the mains.
>
> Anyway SWAMBO has calmed down and the heat pump tumble dryer has been
> working overtime and stuff is going back in the airing cupboard. We are now
> worrying if it will happen again, I might put a pencil mark on the pipe and
> regularly observe it to see if any movement occurs.
>
> Thanks for all the replies.
>
Re my earlier - can you replace the compression fitting with push fit?

<nothanks@aolbin.com> wrote:
> On 25/02/2024 14:35, Tricky Dicky wrote:
>> Tricky Dicky <tricky.dicky@sky.com> wrote:
>>>
>>> Today I had a flood in the bathroom. A compression joint connecting the
>>> copper pipe work to a short length of plastic pipe to the digital shower
>>> mixer failed and being at mains pressure produced a spectacular fountain.
>>>
>>> This joint was made mid December and has been fine ever since. The reason
>>> for the short plastic pipe was due to the pipe clips I was using meant if I
>>> went copper up to the push fit connectors Mira have specified it would have
>>> resulted in an awkward little off-set so the plastic pipe solved that. I
>>> have been scratching my head as to the cause why after 21/2 months?
>>>
>>> At first I thought I may have omitted the insert but it was there, I did
>>> note the olive did not seem to have bitten into the plastic as expected so
>>> there maybe the nut had not been fully tightened, but that usually results
>>> in a weeping join.
>>>
>>> I am a bit old school in that I prefer copper and soldered joins and
>>> compression fittings as necessary and have never felt 100% confident in
>>> plastic and push fit joins other than for low pressure waste pipe
>>> applications. Today’s experience has not improved my feelings about plastic
>>> pipe in mains pressure applications. It has left me wondering if it was
>>> more an external issue namely a temporary spike in water pressure and it
>>> just found the weakest point?
>>>
>>> Anyway, I cannot say I feel confident in the repair and domestic management
>>> was not best pleased with the soaked towels and bedding, especially with
>>> the stuff she had ironed only a couple of hours before.
>>>
>>> Any opinions on the cause and suggested remedies would be appreciated.
>>>
>>>
>>
>> As a few have said it must have been an under tightened nut as the olive
>> just slid off whereas previous compression joints to plastic have resulted
>> in secure olives that could not be removed. It just puzzled me that there
>> had been no weeping which is a common indication of an under tightened nut
>> or that it did not come apart on first pressurisation as we have quite
>> considerable pressure on the mains.
>>
>> Anyway SWAMBO has calmed down and the heat pump tumble dryer has been
>> working overtime and stuff is going back in the airing cupboard. We are now
>> worrying if it will happen again, I might put a pencil mark on the pipe and
>> regularly observe it to see if any movement occurs.
>>
>> Thanks for all the replies.
>>
> Re my earlier - can you replace the compression fitting with push fit?
>

John Unfortunetly I used the plain inserts which have always worked in the
past.

As for push fit fittings I already had the compression fittings spare so
simply used them as such joins always worked in the past. If it looks like
the problem is likely to repeat using push fit will be an option.

On 26 Feb 2024 at 09:55:36 GMT, Tricky Dicky wrote:

> <nothanks@aolbin.com> wrote:
>> On 25/02/2024 14:35, Tricky Dicky wrote:
>>> Tricky Dicky <tricky.dicky@sky.com> wrote:
>>>>
>>>> Today I had a flood in the bathroom. A compression joint connecting the
>>>> copper pipe work to a short length of plastic pipe to the digital shower
>>>> mixer failed and being at mains pressure produced a spectacular fountain.
>>>>
>>>> This joint was made mid December and has been fine ever since. The reason
>>>> for the short plastic pipe was due to the pipe clips I was using meant if I
>>>> went copper up to the push fit connectors Mira have specified it would have
>>>> resulted in an awkward little off-set so the plastic pipe solved that. I
>>>> have been scratching my head as to the cause why after 21/2 months?
>>>>
>>>> At first I thought I may have omitted the insert but it was there, I did
>>>> note the olive did not seem to have bitten into the plastic as expected so
>>>> there maybe the nut had not been fully tightened, but that usually results
>>>> in a weeping join.
>>>>
>>>> I am a bit old school in that I prefer copper and soldered joins and
>>>> compression fittings as necessary and have never felt 100% confident in
>>>> plastic and push fit joins other than for low pressure waste pipe
>>>> applications. Today’s experience has not improved my feelings about plastic
>>>> pipe in mains pressure applications. It has left me wondering if it was
>>>> more an external issue namely a temporary spike in water pressure and it
>>>> just found the weakest point?
>>>>
>>>> Anyway, I cannot say I feel confident in the repair and domestic management
>>>> was not best pleased with the soaked towels and bedding, especially with
>>>> the stuff she had ironed only a couple of hours before.
>>>>
>>>> Any opinions on the cause and suggested remedies would be appreciated.
>>>>
>>>>
>>>
>>> As a few have said it must have been an under tightened nut as the olive
>>> just slid off whereas previous compression joints to plastic have resulted
>>> in secure olives that could not be removed. It just puzzled me that there
>>> had been no weeping which is a common indication of an under tightened nut
>>> or that it did not come apart on first pressurisation as we have quite
>>> considerable pressure on the mains.
>>>
>>> Anyway SWAMBO has calmed down and the heat pump tumble dryer has been
>>> working overtime and stuff is going back in the airing cupboard. We are now
>>> worrying if it will happen again, I might put a pencil mark on the pipe and
>>> regularly observe it to see if any movement occurs.
>>>
>>> Thanks for all the replies.
>>>
>> Re my earlier - can you replace the compression fitting with push fit?
>>
>
> John Unfortunetly I used the plain inserts which have always worked in the
> past.
>
> As for push fit fittings I already had the compression fittings spare so
> simply used them as such joins always worked in the past. If it looks like
> the problem is likely to repeat using push fit will be an option.

I'd just add - make sure the pipe is clean, round and unscored. I had an issue
with an unprotected plastic pipe pushed through a wall, and picked up some
light scratched. The pushfit connector didn't seal to the pipe properly.
--
Cheers, Rob, Sheffield UK

On 26/02/2024 09:55, Tricky Dicky wrote:
> <nothanks@aolbin.com> wrote:
>> On 25/02/2024 14:35, Tricky Dicky wrote:
>>> Tricky Dicky <tricky.dicky@sky.com> wrote:
>>>>
>>>> Today I had a flood in the bathroom. A compression joint connecting the
>>>> copper pipe work to a short length of plastic pipe to the digital shower
>>>> mixer failed and being at mains pressure produced a spectacular fountain.
>>>>
>>>> This joint was made mid December and has been fine ever since. The reason
>>>> for the short plastic pipe was due to the pipe clips I was using meant if I
>>>> went copper up to the push fit connectors Mira have specified it would have
>>>> resulted in an awkward little off-set so the plastic pipe solved that. I
>>>> have been scratching my head as to the cause why after 21/2 months?
>>>>
>>>> At first I thought I may have omitted the insert but it was there, I did
>>>> note the olive did not seem to have bitten into the plastic as expected so
>>>> there maybe the nut had not been fully tightened, but that usually results
>>>> in a weeping join.
>>>>
>>>> I am a bit old school in that I prefer copper and soldered joins and
>>>> compression fittings as necessary and have never felt 100% confident in
>>>> plastic and push fit joins other than for low pressure waste pipe
>>>> applications. Today’s experience has not improved my feelings about plastic
>>>> pipe in mains pressure applications. It has left me wondering if it was
>>>> more an external issue namely a temporary spike in water pressure and it
>>>> just found the weakest point?
>>>>
>>>> Anyway, I cannot say I feel confident in the repair and domestic management
>>>> was not best pleased with the soaked towels and bedding, especially with
>>>> the stuff she had ironed only a couple of hours before.
>>>>
>>>> Any opinions on the cause and suggested remedies would be appreciated.
>>>>
>>>>
>>>
>>> As a few have said it must have been an under tightened nut as the olive
>>> just slid off whereas previous compression joints to plastic have resulted
>>> in secure olives that could not be removed. It just puzzled me that there
>>> had been no weeping which is a common indication of an under tightened nut
>>> or that it did not come apart on first pressurisation as we have quite
>>> considerable pressure on the mains.
>>>
>>> Anyway SWAMBO has calmed down and the heat pump tumble dryer has been
>>> working overtime and stuff is going back in the airing cupboard. We are now
>>> worrying if it will happen again, I might put a pencil mark on the pipe and
>>> regularly observe it to see if any movement occurs.
>>>
>>> Thanks for all the replies.
>>>
>> Re my earlier - can you replace the compression fitting with push fit?
>>
>
> John Unfortunetly I used the plain inserts which have always worked in the
> past.

Not actually my post :-)

However, they will work with plain inserts, but will depend more on
adequate tightening for the seal as well as just the mechanical restraint.

> As for push fit fittings I already had the compression fittings spare so
> simply used them as such joins always worked in the past. If it looks like
> the problem is likely to repeat using push fit will be an option.

Either should work...

--
Cheers,

John.

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