Removing old metric radiator

[opps]

I think the blanking nut the OP posted has a rubber washer inside the top

Flomasta BSP Blank Nut 3/4" x - Screwfix

Order online at Screwfix.com. Brass blank nut. FREE next day delivery available, free collection in 1 minute.

www.screwfix.com

I have purchased those ones in the past, they didn't have a rubber washer when I purchased them.

For some reason, without the washer, they would leak even if the TRV was only letting a dribble past.

 

[Madrab]

I have never had any problems using a 3/4 blanking nut, I do however use a 3/4 blind washer in the end.

I may actually be totally wrong then @opps. Tho I'm absolutely sure there is one size of blank that is slightly too small.

I use the plastic blanks for the appliance valves as temp covers for them.

 

[aveatry]

I use the plastic blanks for the appliance valves as temp covers for them.

Good idea
Op--they are so cheap get them as well

 

[Gregzilla75]

OK, I didn't put enough pressure on the pipe as one attempt to loosen E (after I released and retightened the bleed valve) and the pipe still moved with it and is now leaking under F!!!!

I've tried tightening F but it doesn't budge and I'm scared to put too much strength behind it as the whole thing is held together by paint and every touch of the pipe makes the leaking worse.

It was gushing at first but I've turned the water off in the bungalow and wrapped a load of ptfe under F, which has slowed it down.

I give up. HOpefully it doesn't get any worse before I can get get a professional in to sort it all

 

[aveatry]

Oh dear - im sorry its didn't go too well. I would abandon the idea of trying to re doctorate with the rad off and get someone it to do the rad swap.
There are products that promise to fix leaks even under water maybe try those until you plumber comes.
I dont think turning the water off will make any difference as the heating is separate.

 

[Madrab]

It was gushing at first but I've turned the water off in the bungalow and wrapped a load of ptfe under F, which has slowed it down.

It's slowed down because the pressure (has the boiler a pressure gauge on it?) is being released out the system and the radiator will be draining down and it will eventually stop though the boiler may stop running.

As suggested it's not connected to the mains water so you don't need to be without that. If you loosen off F a 1/4 turn that may allow you to then tighten it back enough to seal it.

 

[ChrisJP]

Those ancient valves would have needed replacement anyway, along with the radiator. To do this, it would be necessary to drain down the entire CH circuit, so by having a leak from "F" you've probably saved the plumber a bit of time!. Where is the water leaking from "F" going? If you have suspended wood floors it's probably draining harmlessly into the void and will either exit via an air brick or just dry up eventually.
I didn't catch whether your CH system is a sealed pressurised one, or is an open vented one fed via a Feed & Expansion tank.
If the former then the amount of water that will drain out via the leak is limited to the volume in the system.
If the latter, the system will keep being replenished via the F&E tank so you need to turn off the water feed to that. If that has a separate valve to turn it off, you do not need to turn off the domestic water feed to the house.

 

[Gregzilla75]

Was lucky enough to get a professional in at short notice. The pipe hadn't bent, just the olive had slipped out of place and the nut couldn't be tightened. He fixed it all up, drained the rad and will give me a quote for installing a new one.
A costly mistake, but you live and learn.
Mentioned it was unusual the way the combi-boiler had been installed. Probably half-a-job install not replacing the whole system as the water tank, I think he said, is still in the attic.
Thanks for all the replies/advice.