How to fix shower bar with only 10mm exposed 15mm copper pipes?

[samba1]

Hi Guys,

Seeking advice. I have a Triton Combi HP (8000/9000) mixer shower, which is giving thermostatic and cross flow issues. I can confirm cold back flowing into hot, because the hot feed is ice cold. I have 3 of these identical showers, and the hots are much warmer than the colds on the other two showers. The second shower the thermostatic control does allow it to get really hot, so I’m tempted to replace all 3. I can get replacement cartridges but at £150 a valve I’m thinking to replace to something more easier to maintain and replace in future.

So, I have (based on the installation manual) about 10mm copper pipe exposed, I know that replacing the Triton mixer I’ll have exposed screw holes on the tiles, which I’m reasonably happy to live with it being filled with grout, not ideal but ok with it. What method would be best assuming the pipework behind the tiles is not secured to fit a bar shower?

I am concerned that I do not have much exposed pipework and so what suggestions do guys have to allow that to be extended to allow a bar shower fixing kit to be used? I think those kits require about 30mm copper pipes? Are there any adapters or extenders etc. that solves this type of issue?

I am guessing (based on the Triton install guide) that the existing 15mm pipe will have an olive and a nut behind it to allow it to secure to the Triton Combi mixer, so is there anything out there that allows me to fairly easily move over to a bar shower.

I have to admit, I’m a DIYer, so guidance on this (apart from getting in a plumber, which I may have to end up doing if absolutely necessary) would be appreciated.

I’ve attached some images to help explain the current installation…

 

[steadyon]

1. I think you will face two issues:
1a. The pipe centres of most bar mixer showers are 150 mm, whereas your existing centres are 153 mm. Doesn't sound much but could be very difficult if pipes are solid in the walls.
1b. The amount the pipes stick out, the problem you have mentioned.
2. I would approach the protrusion issue as follows, but it requires special tools:
2a. Use an olive puller to remove the fixing compression nut and olive.
2b. Use a pipe expander to expand the end of the pipe to take another short (100 mm?) length of pipe. Given the high impact of the stub splitting, I would anneal it first.
2c. Anneal the short length of pipe then solder it into the stub.
2d. Use a pipe bending spring, some wooden wedges, and the length of the new pipe to put a 1.5 mm inward dog leg into the pipe. Bit rough and ready but works if done with care.
2e. Because of the closeness of the wall (inside the 32 mm space for the compression nut) I'd line the gap with some cut up soldering mat and some aluminium sheet before annealing or soldering.
2f. Trim pipe to length.
2g. Repeat for other pipe.
3. The above is a huge amount of faff, and only worth it if the existing shower cannot be rescued.
4. Consider fitting non return valves to the pipework leading to the problem shower as the ones for your shower are discontinued.
5. For the two which run too hot, you may be able to adjust the maximum temperature, you can on most thermostatic mixers. Alternatively consider fitting a Thermostatic Mixing Valve in the supply pipework to each shower, and setting the shower thermostats to max. However, this leaves you with a set temperature, which generally can't be adjusted as the temperature differential for the shower thermostat is not enough to make it work.
6. If you opt for 5. above, replace each shower with a more standard one as the bathrooms are refurbished.

 

[samba1]

1. I think you will face two issues:
1a. The pipe centres of most bar mixer showers are 150 mm, whereas your existing centres are 153 mm. Doesn't sound much but could be very difficult if pipes are solid in the walls.
1b. The amount the pipes stick out, the problem you have mentioned.
2. I would approach the protrusion issue as follows, but it requires special tools:
2a. Use an olive puller to remove the fixing compression nut and olive.
2b. Use a pipe expander to expand the end of the pipe to take another short (100 mm?) length of pipe. Given the high impact of the stub splitting, I would anneal it first.
2c. Anneal the short length of pipe then solder it into the stub.
2d. Use a pipe bending spring, some wooden wedges, and the length of the new pipe to put a 1.5 mm inward dog leg into the pipe. Bit rough and ready but works if done with care.
2e. Because of the closeness of the wall (inside the 32 mm space for the compression nut) I'd line the gap with some cut up soldering mat and some aluminium sheet before annealing or soldering.
2f. Trim pipe to length.
2g. Repeat for other pipe.
3. The above is a huge amount of faff, and only worth it if the existing shower cannot be rescued.
4. Consider fitting non return valves to the pipework leading to the problem shower as the ones for your shower are discontinued.
5. For the two which run too hot, you may be able to adjust the maximum temperature, you can on most thermostatic mixers. Alternatively consider fitting a Thermostatic Mixing Valve in the supply pipework to each shower, and setting the shower thermostats to max. However, this leaves you with a set temperature, which generally can't be adjusted as the temperature differential for the shower thermostat is not enough to make it work.
6. If you opt for 5. above, replace each shower with a more standard one as the bathrooms are refurbished.

Thanks very much for the detailed response. Immensely appreciated!

I can get the existing unit (body and valve) for £150, but thought it’s a 20+ year old design, and maybe if going to that cost and effort to modernise and to standardise for future easy repairs/replacement. I’m fairly certain that the pipework will have a little play, but your idea is very clever.

Forgive me for being thick, what is a pipe expander? Is it a tool that expands the diameter of the existing pipe projecting from the wall to allow another 15mm pipe to sit inside?

Thanks!

 

[steadyon]

Yes. They come in two forms:
1. A swage, which is essentially a punch. The tip fits inside the pipe, 15 mm pipe having an inside diameter of (15-(2 x x0.7)) = 13.6 mm. After a short (25 mm or thereabouts) it flares out fairly steeply but smoothly to a parallel 15 mm diameter. You hammer it into the old pipe, and essentially get a solderable fitting made on the end. Because it is hammered in, it is as well to know what is at the other end of the pipe, or it can easily be damaged. Best used on a free length of pipe which you can hold in one hand.
2. A pipe expander is a tool with a finely tapered hardened steel pin which is driven through the centre of a set of six segments with a matching taper. The pin is driven in by a set of long handles on a pivot. To use, the pin is withdrawn by opening the handles, the jaws, which have a step about 20 mm along are inserted into the pipe, and the handles closed. This forces the pin through the centre of the jaws and expands them outward, expanding the pipe. Because there are six jaws you tend to get a hexagonal pipe. To avoid this the handles are opened part way through the expansion, the device rotated about 15 degrees and the handles closed again. This is done two or three times to give an almost round pipe, and the solder fills any irregularities.
3. Because the pipe is stretched, there is a risk it can crack. Normal plumbing pipe is "half hard" but it can be made soft by annealing it. In the soft condition it stretches readily and there is very little risk of cracking. Annealing of copper is done by heating the area to be annealed to red heat, then either quenching in water or allowing it to cool. The downside of annealing is that it leaves the copper soft and you need to be a bit more careful with compression fittings not to overtighten them and crush the olive into the copper.
4. Swaged or expanded joints are not allowed on gas pipework as it is felt the stresses induced in the copper can lead to fracture. I've never quite seen how the stretching in this way is any different from the stretching which happens when bending pipes, but those are the rules.

 

[samba1]

Yes. They come in two forms:
1. A swage, which is essentially a punch. The tip fits inside the pipe, 15 mm pipe having an inside diameter of (15-(2 x x0.7)) = 13.6 mm. After a short (25 mm or thereabouts) it flares out fairly steeply but smoothly to a parallel 15 mm diameter. You hammer it into the old pipe, and essentially get a solderable fitting made on the end. Because it is hammered in, it is as well to know what is at the other end of the pipe, or it can easily be damaged. Best used on a free length of pipe which you can hold in one hand.
2. A pipe expander is a tool with a finely tapered hardened steel pin which is driven through the centre of a set of six segments with a matching taper. The pin is driven in by a set of long handles on a pivot. To use, the pin is withdrawn by opening the handles, the jaws, which have a step about 20 mm along are inserted into the pipe, and the handles closed. This forces the pin through the centre of the jaws and expands them outward, expanding the pipe. Because there are six jaws you tend to get a hexagonal pipe. To avoid this the handles are opened part way through the expansion, the device rotated about 15 degrees and the handles closed again. This is done two or three times to give an almost round pipe, and the solder fills any irregularities.
3. Because the pipe is stretched, there is a risk it can crack. Normal plumbing pipe is "half hard" but it can be made soft by annealing it. In the soft condition it stretches readily and there is very little risk of cracking. Annealing of copper is done by heating the area to be annealed to red heat, then either quenching in water or allowing it to cool. The downside of annealing is that it leaves the copper soft and you need to be a bit more careful with compression fittings not to overtighten them and crush the olive into the copper.
4. Swaged or expanded joints are not allowed on gas pipework as it is felt the stresses induced in the copper can lead to fracture. I've never quite seen how the stretching in this way is any different from the stretching which happens when bending pipes, but those are the rules.

Wow, another comprehensive response. This has given me some real confidence. The world needs more people like you! Thank you!

Would it be against any good practice if the extending bit of pipe was expanded rather than the protruding stub, or is there specific reasons to expand the protruding stub pipe?

 

[steadyon]

You know a soldered joint is good when you see a ring of solder "flash" round the edge of the joint. If the joint is inside the wall you won't see the flash.

 

[Ric2013]

I must say my first thought was to swage the pipe joint, but I've only done it in Italy, on one occasion, using a pipe expander, and Italian copper tube is much thicker walled than UK, so it's a safer process. Have seen the swaging tools, and they don't fill me with confidence. If the OP can get a mirror behind the joint to see to solder/inspect, then it may be possible to swage the new pipe as suggested instead.

It depends whether samba1 feels more confident soldering and inspecting from behind (perhaps tinning the pipe would make it easier?) or swaging the pipe in the wall, and what tools and skills samba1 has.

 

[steadyon]

Something I should add. Check the requirements of the replacement shower. If it needs 15 mm pipe from the face of the wall you will need to make sure any joint, and consequent increase in thickness, is inside the wall.

 

[ShaunCorbs]

Can you get to the other side of the wall where the shower valve is ?

 

[samba1]

Can you get to the other side of the wall where the shower valve is ?

Yes, it’s possible but would mean hacking into plaster boarded stud partition wall, and redecorating.

 

[ShaunCorbs]

Or installing a neat plastic access hatch eg

https://www.NoLinkingToThis/p/manthorpe-access-panel-white-243-x-193-x-16mm/20924

 

[moonlight]

I removed one of these a few months ago and replaced with a thermostatic bar shower. I used the quick fix kits and had enough movement behind the old shower. The kits cover the holes nicely. Just be careful not to lose the pipes in the wall. Good luck.

 

[samba1]

I removed one of these a few months ago and replaced with a thermostatic bar shower. I used the quick fix kits and had enough movement behind the old shower. The kits cover the holes nicely. Just be careful not to lose the pipes in the wall. Good luck.

Cheers Moonlight, I’m hoping there’s sufficient play too. Which kit did you use? Most kits seem to indicate the need for 30mm pipe protrusion.

 

[moonlight]

You could use these below. It will depend how much your pipe will move when you take off the old shower. Remove olives carefully.