Moving rad using pex piping

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.

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

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.

Good tip, Draining down a system though is always a recipe for problems when you fill it. Usually big problems. Should be easy but never is.

I'm a spark bit my understanding was they're not needed

Good to see we're agreeing at last 😁

All I know about plumbing is back in the day we'd change the immersion heaters but then there was too many problems with leaks

After that it became a job for the plumber

Basically if you look at an olive, it's symmetrical, but the only part which actually makes a seal is the face which goes into the connection under the threads. The face at the nut end is only there to allow the olive be compressed into the joint, making a seal with the surrounding metal as well as forming itself around the pipe.

So by rights, as you said, the only face that actually needs PTFE to make a seal is on that half of the olive, but in practical terms ots not possible to only dress half the olive, so it ends up bring applied over the whole olive.

There are pastes which can also be applied, but again they are applied all over the olive and then the joint tightened up as normal.