Just looking for some views on a plumbing problem. I am making some changes in the bathroom and it requires the re routing of some 22mm hot water pipework with lots of bends etc under the existing bath. I have done lots of DIY plumbing in my time with compression or soldered fittings but a friend suggested that I use this new fangled plastic stuff with clip on joints etc. which will be easier than using rigid 22mm copper pipe. Any views or suggestions given that it's hot water and low pressure?

Thanks Guys 3 x FL1 2 manual + 1 auto
5 x FL2 4 manual + 1 auto
Now Discovery Sport P250 MHEV SE

We used plastic, but used the clip bends for radius bends it stopped the pipe creasing. Plastic seems to be quite normal now.

I've used it quite a lot but be careful which make you buy, some are not able to be dismantled in case of an error in measuring or seeing a better route, some will be able to fit to copper using the same connectors, this is especially useful if using blank ends where you can shut off the water and blank the pipe and return the water to normal whilst carrying out the rest of the work. I have found Speedfix very good from B&Q or Screwfix, I suggest you buy the fittings in multi packs, far cheaper and you will use them. Don't forget the inserts for the plastic pipe as they are needed to avoid the pipe crushing at the joint.
The original recommendations was to not to fit plastic plumbing within 1m of a boiler, but I understand that the distance has now been shortened. I suggest you purchase the cutter which is only a couple of pounds rather than using a hacksaw or knife, the Speedfix pipe has markings on it so you know that it fully inserted in the fittings, the pipe comes in coils or in 3m lengths, the 3m lengths are handy if the pipe is exposed like fitting to a radiator to through the floor as the coils tend to keep their curvature and are difficult to straighten for aesthetic reasons. my PC is slightly to the right of Genghis
2012 HSE SD4 In Orkney Grey now gone, best car ever.

Last edited by Dartman the one on 29th Sep 2022 11:32 am. Edited 1 time in total

I've used plastic for quite a bit of DIY plumbing over the years, especially where hidden.
1) Use the proper cutter
2) Dont make a join with an area of pipe that has scratches, surface damage (eg from pushing it through a wall) - the seal is only via a rubber O-ring.
3) it always seems to retain the curve of the coil
4) dont forget the inserts. Jules

I have used the JG Speedfit stuff on lots of projects for other people and when i got rid of my wood burner with back boiler re did all the plumbing under the floor boards to exsisting radiators from a lpg fired boiler in my loft no problems what so ever just make sure you pipe clip it at proper spacing and use the pipe inserts and lock the connectors when connected  2009 FL2 S now gone
2011 FL2 HSE AUTO
2012 FL2 XS AUTO
2000 Kawasaki er 5

Hep2o plastic pipe and fittings. Make sure you use the metal insert in the pipe before inserting into the fitting. Now at the point when I learn something new something old is lost out the other side !
Now retired so it doesn't matter anymore.
Freelander now gone.

The other thing to be aware of is that if you are splicing any plastic into copper pipe that has a supplementary / cross earth bonding fitted , that you make sure that you haven’t created a future safety issue . 2009 GS Auto Zermatt Silver - Sold June 21 after 10 years of ownership

2016 Subaru Outback SE 2.0 diesel SE Premium Lineartronic Sold 2024 after 8 years and 80k miles . Best Car I ever owned !

2023 Toyota Hilux invincible X 2.8 Auto .

Thanks guys but had a senior moment in the process, I bought a pack of 5 elbow joint and a pack of 5 pipe inserts. When I got home I realised that you need two inserts per joint ie one per pipe going in. Duh  3 x FL1 2 manual + 1 auto
5 x FL2 4 manual + 1 auto
Now Discovery Sport P250 MHEV SE

I am an old engineer who was taught that O-rings had a 10 year life expectancy if they were in applications that required movement. Plastic pipes move with expansion and vibration, so are the O-rings different to the ones we used to use, or are we asking for pipework joints to weep after 15 years or so? Tangiers Orange - gone, missing her
Replaced by Ewok what a mistake - now a happy Disco Sport owner

With the water in this part of Dorset, any minor seepage will self-seal with limescale in a matter of seconds  Current driveway contents:
2021 V60 Cross Country B5
2009 FL2 dog bus and shooting wagon

On Order: 2023 Fisker Ocean Ultra - deposit paid.

Andy131 wrote:

I am an old engineer who was taught that O-rings had a 10 year life expectancy if they were in applications that required movement. Plastic pipes move with expansion and vibration, so are the O-rings different to the ones we used to use, or are we asking for pipework joints to weep after 15 years or so?

Cheers Gents.

Our water is ridiculously soft so no limescale - algae / slime on the other hand by the bucket load.
I put in a Japanese style toilet a couple of years ago when the Mrs was poorly, this has plastic pipework and was going to disconnect it, in the belief that the O-rings would eventually fail. But in 40 years I will be long past caring. Tangiers Orange - gone, missing her
Replaced by Ewok what a mistake - now a happy Disco Sport owner

Well I finished the plastic plumbing job OK and everything was OK until I noticed that my hot water cylinder has a slight weep around the immersion heater. It looks like it's been there for some time so not caused by any recent disturbance by me and hopefully it's coming from the immersion heater thread rather than caused by corrosion of the copper itself. The tank was fitted only 5 years ago which doesn't sound a long time to me. This is a hard water area and I have had tanks replaced before. Has anyone got experience of moving to stainless steel cylinders? 3 x FL1 2 manual + 1 auto
5 x FL2 4 manual + 1 auto
Now Discovery Sport P250 MHEV SE

In my previous house I had the CH & DHW system upgraded. New SS cylinder. Pressure vessels for both CH and DHW. Threw out the old CH header tank & bulk tank to head the DHW system in the loft & boarded it. Airing cupboard became less effective due to !, larger cylinder & 2, better insulation.

Now in a "ECO" modern bungalow with thick walls, thicker double glazing, lots of loft insulation and ASHP supplying DHW and underfloor heating, suplemented by Solar Panels. The cylinder is much like the previous one but even bigger, in it's own little room with electrickery including inverter etc. I call it "Mission Control". Room for a clothes airer so I don't need a tumble dryer any more!

Bob 10MY (Sept 09) TD4 HSE Auto in Stornoway Grey (Now Gone)

08 FL2 TD4 SE Manual in Rimini Red (Now Gone)

dorsetfreelander wrote:

Well I finished the plastic plumbing job OK and everything was OK until I noticed that my hot water cylinder has a slight weep around the immersion heater. It looks like it's been there for some time so not caused by any recent disturbance by me and hopefully it's coming from the immersion heater thread rather than caused by corrosion of the copper itself. The tank was fitted only 5 years ago which doesn't sound a long time to me. This is a hard water area and I have had tanks replaced before. Has anyone got experience of moving to stainless steel cylinders?