Removing a radiator - advice please

I once did as you are suggesting with your rad valves in our en-suite and went away for a few days mid task ...... the insurance paid for a new carpet due to the flood. I just never gave the thermostatic valve a thought. 

You'll flood the place when/if you cut the pipe before either of the valves. Ideally you'll need to drain the system around the radiator .... depends really on where your boiler is relative to the radiator and whether the pipe works goes up or down to the rad. Freezing the pipe is also an option ....... 

If the radiator valves are both switched off, including the thermostatic one if fitted, there should not be a problem. It is possible to cut the pipe to extend but a right B if you fluff it. When I had a pipe replaced in the bathroom for a new radiator I suggested that I would assist. Plumber cut the pipe; I put my finger over the end and then when he was ready the fitting was shoved in place with very little spillage. Not a method for the faint hearted. 

If you were to replace like for like radiators, same size, same pipe fit, then you could probably valve off quite easily. But if not, draining down would probably be safest and less prone to water damage. My OH took out an old radiator and put in a much nicer more architectural one in our old house, drained down system prior, and we had no damage. Refilling requires patience and just checking each and every radiator in house a good few times to eliminate air locks, but we found it a good check on al radiators to ensure valves working ok. It's not a big job draining down, just more time consuming. If you can, fit a hose pipe to lowest drain point and take water out through this. Good luck.

Ian,

Turning off the thermostatic valve will not work -as soon as the room cools down the valve will reopen .

We learned this many years ago when we bought our first house and were decorating before we moved in. My dad removed the radiator and I called round to the empty house the following day. Opening the front door I was astounded to see the ground floor covered in an inch of water and the sound of water still pouring of the radiator pipes. All carpets were obviously saturated and took days and days to dry!

There are two ways

1) When purchased the thermostatic valve may have been supplied with a plastic top which replaces the thermostatic head and can be screwed down tight to stop the spindle rising.

2) Any plumbers merchants/B&Q etc will sell a female cap end which is simply screwed on to the side of the thermostatic valve ( in place of the radiator. You can also use a cap end on the lock shield valve to be doubly safe. I can't remember what diameter the cap ends are but are probably 22mm and 15mm 

When our thermostatic valves and those at my daughters house are off then they are off. They will not come on if temperatures fall. On hours off is off and not a frost setting.

A good quality thermostatic valve will have an off position. Mine has various temperature settings then a frost protection setting then an off position. Some cheaper valves may not have this. If yours have it you will be fine, but don’t forget to close the lock-shield valve as well making a note of the number of turns required to close it, and when you have finished the tiling open by the same amount as this value is usually used to balance the system properly.

You will not be able to cut the pipe on the live side without draining down the system unless you invest in a freezer kit which will freeze the water in the pipe allowing you to cut it and make the required modification, but I would recommend draining the system.

If you do drain the system don’t forget to add some inhibitor (Sentinel or similar) when you refill.

Thank you for all your tips and advice.

Anyway, took the radiator off today, after closing both valves. No real problem, just put old towels under to catch a few spills.

The thermostatic valve only has a 'frost' setting, not an 'off' setting.

Put the central heating on to check it and there was a dribble from the thermostatic valve - probably a cheap and nasty one.

So......decided to remove it and fit a capping fitting. Decided to use the 'Easy T method', unfastened the thermostatic valve, put my thumb over the pipe (which was like a geyser!) and had the capping fitting ready to put on.

Trouble was, the old brass olive appeared to be welded to the pipe, preventing me from putting on the capping fitting 

Refitted the thermostatic valve and accepted the dribble for a while. Have now turned the heating down so low that it would take an ice age for it to come on. We will just have to manage until the tiling is done and the new rad is fitted.

For the latter, I will need a freezing kit........or a good, cheap plumber!

'So......decided to remove it and fit a capping fitting. Decided to use the 'Easy T method', unfastened the thermostatic valve, put my thumb over the pipe (which was like a geyser!) and had the capping fitting ready to put on.

Trouble was, the old brass olive appeared to be welded to the pipe, preventing me from putting on the capping fitting'.

That is why I offered to help the plumber ............. two man job. 

Well done Ian .

May I suggest that, if possible, gate valves are included on the pipework to make it easier in the future. Maybe for someone else if not yourself.

I am not sure this is the time of year to be attempting to change elements of the central heating system. Removing a radiator to do some decorating is one thing but anything that requires new parts to the pipework is best left to warmer times of the year where it makes no difference if you have the heating on. It also allows you to drain the system down making any work far less risky. By all accounts we have an artic blast coming our way. You won't be the most popular person with Mrs H if she has no heating

David