Replacing an old heating system with plastic piping

[cf-leeds]

Hi,

It's fallen on me to replace the piping and rads for my parents' central heating system.

The radiators are very old and badly sludged, as is the piping. The piping is actually plastic piping, which was fitted in the late 70s and has now started to deteriorate, to the extent that an upstairs radiator pipe recently developed a crack (while they were on holiday naturally), causing a serious flood. Hence time to rip out the lot.

I don't know what the official name for this black plastic tubing is, but the only difference between it and copper seems to be that you need both a nipple and olive for the compression fittings.

I now want to use 10mm copper pipe for ease of install, but would also like to use a flexible 22m pipe from the boiler flow & return, to the upstairs and downstairs manifolds.

Can anyone advise on whether this is possible. Is there such a thing as a 22m plastic pipe, which can use a compression fitting onto the existing bolier flow and return, as well as the manifolds ? This is a vented system, so pressure shouldn't be too high.

I'm not interested the speed-fit type solutions, as I simply do not trust them for long-term installations.

I can manage 10mm copper from the rads to the manifolds, but for the main flow and return to the bolier, there's no way I can install 22mm copper in the current pipe runs, which are the original black plastic pipes. If I can find a flexible plastic solution, I can obviously just tie the new pipe to the old and draw them into position.

Any advice appreciated.

Chris

[Tabby]

I could be wrong, but I think normally piping within a certain distance of the boiler should be in copper.

NT

[chris French]

In message , cf-leeds writes

Alkathene maybe?

You can get Speedfit and Hep20 (and presumably others) pipe in 22mm. I used Hep20 on the Ch in install in my old house.

you use compression fittings on them - though it's easier to get the push fit right. Remember you need a pipe insert, a bit of PTFE tape around the olive helps with the seal (i think cos unlike copper it doesn't always seal in the same way as the pipe is softer). And don't over-tighten. It's easier to nip it up a little more if it weeps.

Cehck with the pipe you use over the connection to the boiler. when I used Hep20 they said to use 1m of copper first - IIRC Speeedfit has the same sort of stipulation.

[Lobster]

That was definitely specified in the installation instructions for the W-B boiler I had fitted not long ago. Can't remember the specified distance - maybe 2m? It's a temperature issue, BTW: not pressure.

David

[chris French]

Yup, though it seems often that is the only type sold, probably not worth carrying both types.

Though AIUI, the OP wants to use plastic on this run because of access issues.

small point though, the OP says he wants flexible pipe so he can pull a run through, without joints. Whilst the plastic pipe is flexible, it's not flexible like a hosepipe . so depening on the ipe run could still be difficult if it needs sharpish bends.

[Grimly Curmudgeon]

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember chris French saying something like:

They all do. I visited a boiler which had been installed by a cowboy who'd run the Qualpex pipes right up to the boiler - amazing it lasted so long, but even Qualpex couldn't stand it for more than a few months.

[YAPH]

I'm interested what type of pipe that was. I understand there were some rigid solvent-weld PVC systems around about that time, and there was Bartol Acorn - the forerunner of Hep2O, which IIRC was black.

Sounds like the Acorn pipe but that stuff should last forever, not deteriorate and split. Can you see any markings on the pipe? It would be very interesting to know what it was and, if it is Acorn, to get onto Hepworth and ask them about it, maybe they'd be interested in having a look at it.

yuk, but your choice!

You have to do the first 600mm or 1m from the boiler in copper (should say in the boiler manual) but after that you can use any polybutylene (PB) e.g. Hep2O, Polypipe or polyethelene cross-linked (PEX) e.g. Speedfit (they also do PB). I'd definitely get a feel of the pipe before you buy it: 22mm, especially PEX, can be insanely springy and hard to work with and some makes are easier than others. Most pipe on sale today is barrier pipe but worth checking. For use with compression fittings you need plain metal or plastic inserts, not Speedfit's types with rubber rings on them (those are for use in push-fit fittings). I generally go for copper rather than brass olives onto plastic pipe.

[ARWadsworth]

It could be Acorn, which was black. I asked my mate when plastic pipe was first used and got the following reply

"Without any authority I think the first waste pipes may have been made by a Dutch firm called Wavin who were owned by Shell (who supplied the polypropylene, and later ABS powder). Wavin set up a factory in Wiltshire and sold waste products under the Osma trademark, and still do.

This was followed by PVC rainwater gutter and fittings, at which point Kevin McDonald set up Bartol Plastics in Edlington in competition, later bought out by the Hepworth Iron Company of Hazlehead, makers of clay pipes. McDonald then left, set up McDee Plastics making skateboards etc, and then created Polypipe, in direct competition with Bartol, Wavin, Hunter, Paragon, and others.

Polybutylene pipe for drinking water was introduced by Bartol Plastics around 1982 under the tradename Acorn, to complement the fittings introduced in c1979; Acorn later was renamed Hep2o.

Hepworth Building Products was bought out by Wavin in 2005, just as I left."

[Steve Walker]

My parents' house was done in a black plastic (12mm, 10mm, 8mm and even

6mm OD) flexible tubing (supplied in long, coiled lengths), connected with compression fittings - the "olives" actually fitted up the inside of the tubes (8mm and up) and over the outside, leaving a short brass stub protruding, of equal diameter to the tubing.

That was installed in 1972 and became brittle and very prone to accidental damage about thirty years later.

SteveW