Moving rad using pex piping

DC999

1st time poster here so go easy on me 😊

Am moving a rad across a room and watched all the usual YouTube stuff so feeling grand with how to do it in practice. Never worked on a rad before. What width pex piping do I need in mm? Looks like a standard rad is 15mm, so 15mm pex is used for that.

2) Anyone who has moved a rad or replaced the copper with pex on it want to step through how they went about it? I plan to ‘bung’ the expansion tank in the attic to keep a vacuum so whole system won’t drain and save eme having to clear air for every rad (one old rad at least has has a stuck air vent, so air won't come out of that)

3) I think I’ve an vented cylinder / open-vented / gravity-fed systems. I’ve the expansion tank in the attic. Weirdly I’ve also an expansion tank - thought they were only used with unvented systems. So that has me confused

The Continental Op

What your YouTube videos won't tell you is that in Ireland we (mostly) use imperial fittings so thats 1/2 inch pex not 15mm, but might be 15mm pex ;-)

So make sure you know which you have and get fittings accordingly. They are interchangeable to a point but ideally you need different olives on the compression fittings otherwise make sure you have the correct fitting for tectite etc.

mickdw

Should be straight forward enough job. Amateur myself but have changed rads and moved rads etc. Get the right tools and the right fittings and you should be sound.

Even When bunging the tank, prepare for lots of water. I did that once and whether it didn't quite seal or whatever, but alot of water escaped.

There is a big difference between doing these jobs in a finished room or a room that's a building site. If you are not worried about abit of water getting on the floor, you cant really go wrong.

10-10-20

Yes, agree with mickdw here, I've done lots of small jobs on my heating over the years and I can do it fine without a full drain-down… but there are tricks to it.

Firstly, often the valve from the cold water tank in the attic sticks open and can't be sealed off fully. You may need to play with that to get it to close off enough to start.

Second is that I always have a Vax nearby just in case it floods more than I expected.

Third is that you can often temporally cap-off a half-inch pipe using a stop end applied loosely (as long as there isn't any water pressure). Have one handy, link below.

Fourthly, lookup how to apply PTFE tape properly.

Fifthly, make sure you have a good adjustable wrench as a standard pipe pliers will damage the fittings and wreak your head.

Sixth, use a marker on each joint to mark when you have installed an insert, then an olive and then tightened it fully.

Seven, add in inhibitor to the rad before refilling (it can be a real b1tch to get in on some rads). Then refill it slowly while venting the new rad.

Lastly, expect weeps on the joints and make sure to check them after an hour, a day a week…

https://www.plumbingproducts.ie/compression-nuts-ireland/396-compression-stop-end-351-3-4.html

Good luck

DC999

Thanks all. Appreciate the help

rob316

Best of luck, but I'd drain the system, it doesn't take long.Absolute last thing you want is alot of water and panicking doing a DIY job.