I agree with DSD...I have to teach this as part of ICA/'NVQ's...the first thing I tell the trainees...'dont get involved' get a plumber out, I have done jobs for people, offer to drop the rads for them in order to paper behind.
Getting em off is easy..the trouble starts when your putting them back..leaky valves, you might snap the valve off, ruin the olive, or get an air lock int he system when you refil it.
You try and save the customer a few quid and run the risk of costing yourself a fair bit of money in the process.
Leave it to the experts.
So very true Zamps as I found to my cost.
Thought I was doing them a favour, and it was only a little rad, took it off no problem, everything went well, stripped behind, papered and put rad back on, worked okay.
The man never said a word to me about any problems, so when I finished the job and had my hand out for my payment, he then turned round and said, he will deduct X amount, I cant remember how much it was, as this happened a good few years ago.
I asked him why, he said he had to get someone in to sort the pressure out in the boiler, I asked why he never mentioned it to me as I would have got someone in if need be, he didnt really give me an answer.
He was a big man, so I took my money, did a little detour, as I had left something upstairs, then came down and ran like hell.
I have never taken a Rad off since, not for customers anyway.