# One for the plumbers please



## Lazurus (28 Feb 2022)

I am putting a small Triton T30i over sink water heater into the new workshop build. Mains supply will be via a 25mm HDPE main, I want to use HEP 20 or similar plastic pipe for the inside runs, my question is can I put the 15mm plastic pipe into the standard compression and olive fitting on the water heater or will I have to use copper. A quick search on you tube says the plastic pipe IS compatable with compression fittings but I would rather hear from some one who has actually used this or similar.
Cheers


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## owen (28 Feb 2022)

Lazurus said:


> I am putting a small Triton T30i over sink water heater into the new workshop build. Mains supply will be via a 25mm HDPE main, I want to use HEP 20 or similar plastic pipe for the inside runs, my question is can I put the 15mm plastic pipe into the standard compression and olive fitting on the water heater or will I have to use copper. A quick search on you tube says the plastic pipe IS compatable with compression fittings but I would rather hear from some one who has actually used this or similar.
> Cheers



You can use 15mm hep into a compression fitting aslong as you use an insert. You can also put 15mm copper pipe straight into hep fittings.


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## SamG340 (28 Feb 2022)

Yes with an insert but seems a bit dodgy really to me, personally I'd use a little bit of copper and then a push fit from there


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## SamG340 (28 Feb 2022)




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## SamG340 (28 Feb 2022)

Make sure you clamp the hep properly ! Don't want it getting pulled out and leaking


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## Lorenzl (28 Feb 2022)

I think you are supposed to use a certain length of copper out from the boiler before you go into plastic.


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## MARK.B. (28 Feb 2022)

copper to plastic as samg340 say's is the way i did mine around ten years ago and never had a problem , i plan to upgrade to a larger heater in the near future and will do the same again


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## Jones (28 Feb 2022)

You can use plastic into a compression fitting with the insert but if the fitting is short there's not much engagement with the speedfit type as the sleeve is quite long,the olive can end up right on the end of the pipe. I have the same water heater, I used chromed copper to below worktop then pushfit into plastic. With chrome you need to sand off the chrome in the pushfit so it can grip.


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## Phil Pascoe (1 Mar 2022)

Lorenzl said:


> I think you are supposed to use a certain length of copper out from the boiler before you go into plastic.


It's an inlet not an outlet.


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## chris.s (1 Mar 2022)

I wouldn't bother with any type of instant hot water hand washer they are made to satisfy hygiene standards which in winter they often fail as to get to required temperature you are turning the flow down to a point that they swith off and as for the spray nozzles in a hard water area they don't take long to block, a small mains pressure under sink unit will give a more reliable supply for hand washing and enough to half fill a bucket for other uses ( but set pressure on expansion tank after installation I lost count of how many I've found not set )


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## Doug B (1 Mar 2022)

I installed a Triton hand wash in the workshop nearly 2 years ago during the first covid lockdown, my only regret is I didn’t do it years ago. It is only a hand wash so don’t expect gallons piping hot water but for washing out brushes etc & of course hand washing it’s spot on.








If using plastic pipe in compression fittings I prefer to use a stainless steel insert 








Hep2O Smartsleeve Pipe Support 15mm | Toolstation


Push-fit Hep2O includes unique features that enable quick and easy installation with a secure fitting. It is the only push-fit plumbing system with joint recognition, secure demounting and a 50 year guarantee. The system is compatible with both plastic and copper, making it ideal for new...




www.toolstation.com




I also wrap a few turns of ptfe tape around the olive before assembly, I’ve been doing this for the last 20 years & never had a problem.


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## andy48 (1 Mar 2022)

1. As you know, you have to put a pipe insert into any plastic pipe at a connection.
2. If you use Hep2O pipe, their standard inserts are fine.
3. If you use JG Speedfit pipe, they do two types of insert, "Superseal" (with added O rings like post #4 above) and plain. With compression fittings, the superseal don't give enough depth of insertion and the plain inserts should be used.
4. It is considered better to use copper olives, rather than brass ones, on the plastic end of a compression joint. It compresses better onto the softer plastic. 
5. Do check the manufacturers instructions.
6. Note that there is a filter fitted inside the pipe at the final connection. I doubt this will fit a plastic pipe with an insert in it, although a Hep2O insert is more likely to suit. The supplied olive looks like a brass one.
7. There is a requirement to fit an isolation valve before the inlet. I would:
7a. Fit a decent full bore isolation valve like a Pegler (e.g. Screwfix 11085) with a short length of 15 mm copper pipe from valve to T30i inlet.
7b. Connect the plastic pipe into the isolation valve as described above.


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## Scruples (1 Mar 2022)

chris.s said:


> I wouldn't bother with any type of instant hot water hand washer they are made to satisfy hygiene standards which in winter they often fail as to get to required temperature you are turning the flow down to a point that they swith off and as for the spray nozzles in a hard water area they don't take long to block, a small mains pressure under sink unit will give a more reliable supply for hand washing and enough to half fill a bucket for other uses ( but set pressure on expansion tank after installation I lost count of how many I've found not set )


Washing hands in cold water, with soap, is hygienic. I'm unaware of any standards for the temperature of water for handwashing.


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## Spectric (1 Mar 2022)

Normally from a heat source the first run is copper, also yes " It is considered better to use copper olives, " rather than brass. Personaly I am old school and have both a pipe bender and the skills to fit copper so I only use plastic pushfit as a temporary job to maintain supply. The pegler Tectite fittings are ok on copper, easy to use and not as bulky as plastic pushfit and give a better looking job.


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## Spectric (1 Mar 2022)

People must be softer these days, I have worked in places where the hand washing facility was just an outside cold tap with a tin of swarfega handy! Are you really going to get dirty hands in a woodworking environment .


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## Lazurus (1 Mar 2022)

chris.s said:


> I wouldn't bother with any type of instant hot water hand washer they are made to satisfy hygiene standards which in winter they often fail as to get to required temperature you are turning the flow down to a point that they swith off and as for the spray nozzles in a hard water area they don't take long to block, a small mains pressure under sink unit will give a more reliable supply for hand washing and enough to half fill a bucket for other uses ( but set pressure on expansion tank after installation I lost count of how many I've found not set )


Hadn`t the room for anything else, I will see how it goes.


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## chris.s (1 Mar 2022)

Scruples said:


> Washing hands in cold water, with soap, is hygienic. I'm unaware of any standards for the temperature of water for handwashing.



there is for commercial premises it's for control of legionnaires infection can't quote you all the regs now as they went in the recycling when I retired


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## Phil Pascoe (1 Mar 2022)

That's for the standing water in the system though, isn't it? Not the actual washing.


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## chris.s (1 Mar 2022)

Phil Pascoe said:


> That's for the standing water in the system though, isn't it? Not the actual washing.



don't know which premises are covered by which regs but there were also anti-scalding checks we had to carry out in care homes and nurseries to check the mixing valves were working and the cold water had to be under 20c within 60 sec. We also contracted to Sainsbury and they followed a similar testing schedule.


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## Phil Pascoe (1 Mar 2022)

That's to make sure the water isn't too hot rather than specifying a minimum temp. for hand washing, though. Sorry, I'm not trying to be obtuse.  
I know when I was in hospital I couldn't get a hot shower for love nor money because of the thermostatic controls, but I've not read of any regulation that says you must wash your hands in hot/warm water. There probably is a regulation for food handling premises that specifies hot water should be available, though.


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## Spectric (1 Mar 2022)

You will find that even the water in a hot water cylinder has to be above a minimum temperature to prevent bugs, look at 






Managing legionella in hot and cold water systems


Provides links to sources of information and guidance on health and safety in the health and social care services sector.




www.hse.gov.uk


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## Steve_Scott (2 Mar 2022)

Plastic and compression are fine… sort of..

As others have already stated, you must use the correct insert (ie the one for the pipe brand, and if using Speedfit, the TSM, not superseal). Do not swap inserts between brands, outside diameter is standardised but inside/wall thickness is not. A sloppy insert is not effective.

Do not use any sealants or PTFE tape with compression fittings when making the joint. If a fitting weeps after making it, then you can add a wrap of ptfe around the olive or a smear of LSX but generally a weeping fitting means it’s not tightened enough and adding sealant material at the point of making the joint can hide an inherent mechanical weakness.

Critically, tighten the joint properly. Most compression joints on copper are under tightened by manufacturer’s own instructions (where supplied), and very few manufacturers provide specific instructions for forming joints onto plastic (which is viscoelestic and has significant wall thickness so has the potential to shift over time). I’d have to check my records but I think only IBP/Conex supply specific instruction for plastic pipe. Likewise, plastic pipe manufacturers don’t provide specific advice because they don’t make the fittings. I would always recommend tightening a compression joint onto plastic pipe significantly tighter than an equivalent joint onto copper. Hand tight plus 1.5 turns would be a good starting point.

Check the instructions for the heater about the use of plastic into the box. You can’t do this with a boiler’s flow and return but I suspect you’ll be ok on a instant hot water heater. I think I saw an earlier post suggesting a service valve should be added before the unit; not saying this is wrong but just check instructions as some units require a particular length of pipe to allow hot water to expand into.

For a bit of context, I’m not a plumber; I’m a forensic investigator that has somehow specialised in plumbing failures. Very good at pointing out how not to do it but can’t solder for dung!


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## chris.s (2 Mar 2022)

Steve_Scott said:


> I think I saw an earlier post suggesting a service valve should be added before the unit; not saying this is wrong but just check instructions as some units require a particular length of pipe to allow hot water to expand into.
> 
> For a bit of context, I’m not a plumber; I’m a forensic investigator that has somehow specialised in plumbing failures. Very good at pointing out how not to do it but can’t solder for dung!



I think the units that required the length of pipe for expansion are now outlawed under water regulations from being mains fed and you are required to have a non return valve, expansion tank and relief valve fitted and of course you need an isolation valve for the maintenance engineer to come and replace the leaking pressure valve that has been dripping since installation and now worn away the brass seat because the installing plummers never set the pressure in the expansion tank !

Also not a plumber but have cursed them a lot in the past.


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## Limey Lurker (2 Mar 2022)

chris.s said:


> there is for commercial premises it's for control of legionnaires infection can't quote you all the regs now as they went in the recycling when I retired


I suspect that hot water is insisted on, because cold water would be too uncomfortable for people less srcupulous about cleanliness.


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## flying haggis (6 Mar 2022)

Steve_Scott said:


> A sloppy insert is not effective.


Oooooh Matron............
(fetching coat)


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## Spectric (6 Mar 2022)

Steve is treading very close to being moderated, I believe there is a wokie from the PC brigade stalking these forums and willing to go back to the year dot looking for anything anti woky or that can been complained about just because they can and have a sad life with nothing else to do. Soon sloppy will become a banned word and "normal" takes another hit.


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