Replacing cistern in mobile home

kkelly77

I'm going to be replacing a leaking plastic cistern in a mobile home and I'm looking for some advice. (some photos attached)

The infeed is 15mm of what I think is Qual-PEX. I want to put a push fitting isolation valve on it as there isn't one fitted.

Can I use a push fitting for this type of pipe and do I need an insert, or is that only required for compression fittings?

kkelly77

I have discovered that the plastic infeed pipe is 15mm. I want to put a 15mm isolation push fit valve on the pipe.

I understand that metric fittings are typically used in the UK but what I don't understand is why I can't source one here, in any plumber/heat merchants. :mad: It is infuriating to say the least.

Does anyone know where I can source a fitting like THIS locally, including the 15mm pipe inserts? Thanks.

Sleeper12

Why not just use compression fitting?

Calahonda52

what I don't understand is why I can't source one here, in any plumber/heat merchants

how far out in the sticks are you: this stuff is readily available in Dublin

You can get a 15mm to 12.5 mm 310 reducer and then go 1/2", unless the replacement cistern is 15 mm

kkelly77

Sleeper12 wrote: »

Why not just use compression fitting?

Couldn't get 15mm pipe inserts.

Calahonda52 wrote: »

what I don't understand is why I can't source one here, in any plumber/heat merchants

how far out in the sticks are you: this stuff is readily available in Dublin

You can get a 15mm to 12.5 mm 310 reducer and then go 1/2", unless the replacement cistern is 15 mm

As above, no inserts. I considered that option as well but I just want a neater, simpler solution. Too many potential points for leaks in reducer setup.

Sleeper12

kkelly77 wrote:

Couldn't get 15mm pipe inserts.

Davies in Harmonstown could have some. I know they used to stock that pipe.
The fittings for it were horrible. They weren't push in fittings, they were plastic compression with screw ends. The ESB contractors used them for fitting electric showers. I hate coming across them. They have a tendency to leak with just a little movement on the pipe.

kkelly77

Sleeper12 wrote: »

Davies in Harmonstown could have some. I know they used to stock that pipe.
The fittings for it were horrible. They weren't push in fittings, they were plastic compression with screw ends. The ESB contractors used them for fitting electric showers. I hate coming across them. They have a tendency to leak with just a little movement on the pipe.

Any experience with the reliability of the JG Speedfit fitting I've ordered?

Sleeper12

kkelly77 wrote:

Any experience with the reliability of the JG Speedfit fitting I've ordered?

None I'm afraid. I tend to stick to with compression but a tectite elbow can be a lifesaver in hard to reach places

my3cents

OP, I've had this issue (I have a static caravan), I think what you have iirc are Hep2O pipe and fittings. Due to frost damage I eventually replaced all the pipework a mix of copper and plastic with Qualpex. Initially I was replacing it bit at a time and had the 15mm to 1/2" issue.

What I would do is check the pipe where it joins the cistern for an insert. If there is one then cut the pipe off about 4 inches above the floor and use the insert from the cistern end (may take a bit of getting out but can be done) and fit a brass 15mm compression isolation valve. Get one on Amazon if you can't find one anywhere else. Then finish the job with 1/2" Irish Qualpex which you can get all the inserts etc for. Ideally use a 1/2" olive when you use put the 1/2" Qualpex into the 15mm fitting.

No problem if a real plumber wants to say thats wrong however it works.

If you get the new cistern and can cut the pipe at the exact location needed and reuse the old insert then a flexible 15 mm tail with built in isolation valve would do the job for you https://www.amazon.co.uk/Flexible-Braided-Connector-Isolator-Valve/dp/B010SFNKYO/ .

Sleeper12

Found a push in basin flexi that should get you out of trouble Here

my3cents

kkelly77 wrote: »

Couldn't get 15mm pipe inserts.



As above, no inserts. I considered that option as well but I just want a neater, simpler solution. Too many potential points for leaks in reducer setup.

Not ideal but I've just measured a Hep2O insert, its almost exactly 11mm outside diameter and side by side a Qualpex insert is 00.15mm larger at 11.15mm so it might make the pipe a tight fit in the push fitting but a Qualpex insert should work for you. Pretty sure I used the Qualpex inserts in the 15mm pipe when I was first patching up our caravan.

There are two styles of genuine insert the older one is plain stainless steel with no fancy features the newer ones have a wavy top section and a couple of little barbs built into the body so they don't pull out as easily.

kkelly77

Thanks for all the advice and suggestions.

I got the job done over the weekend except for the isolation valve, which I've ordered from screwfix.

The top of the Hep20 pipe did indeed have an insert for the screw on 90 joint connected to the cistern fill valve.

The biggest issue I had was leaking from the siphon nut below the cistern and the flush pipe nut when everything was assembled. The new siphon and flush pipe nuts appeared to be of inferior quality compared to the original ones that were on the old cistern. As well as that, the replacement rubber washer for the flush pipe-siphon connection was too big which meant the flush pipe nut could not with screws on squarely or correctly.

After several attempts, I ended up using the original nuts, original flush pipe washer and some PTFE tape for good measure. I know there should be no need for PTFE on these plastic connection parts but the connections around the bottom of the siphon were constantly weeping.

my3cents

You'll find a lot of modern cheap plumbing fittings are just that cheap.

I must replace the cistern in our caravan sometime. Its got a splits in the back of it due to the steel mounting screws rusting but the water level is just below the split, so I hope you used a couple of stainless or brass screws inside the cistern to mount it.

kkelly77

my3cents wrote: »

You'll find a lot of modern cheap plumbing fittings are just that cheap.

I must replace the cistern in our caravan sometime. Its got a splits in the back of it due to the steel mounting screws rusting but the water level is just below the split, so I hope you used a couple of stainless or brass screws inside the cistern to mount it.

Used brass screws but they secure at the very top of the cistern, no where near the water line. The old cistern mounted the same but the hairline crack was around the middle of the back of it.