Replacing a radiator

Yukster

Yukster

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I am due to get a new cast iron radiator to replace my existing knackered one. I’ve done a bit of youtubing and I think I sort of know what needs doing. I would be grateful if you could check my to do list let me know if I got it covered?

Turn off the boiler and let the system cool down
Drain the system from the radiator by the front door + turn the lave back off
Take the existing radiator off
Move the T copper junctions to correspond with the new radiator connections
Connect the incoming (the thermal valve) and outgoing pipes
Refill the system – is there anything I should do other than open the water tap on the boiler?
Add Corrosion inhibitor – how do I do that?

Have I got it covered and what else do I need to do to avoid problems

Thanks
 
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Sealed system then I assume? If you can get away with not draining the whole system then I wouldn't worry about more inhibitor unless it hasn't been done in years already. Easiest way if you've got a towel rail somewhere you can often undo the bleed cap (the whole thing, not just with a bleed key) and pour it in before you fill up... Otherwise you'll need a method of injecting it via the filling loop or the aerosol type which spray in.
 
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Yukster said:
St0rmer66 said:
Sealed system then I assume?
Click to expand...
I presume so. I've got a Vaillant ecotec plus combi-boiler and a of rads dotted around the house

St0rmer66 said:
If you can get away with not draining the whole system
Click to expand...
Is there a way of moving the copper upright connections (the new rad is smaller than the old one) without draining the heating system?
Click to expand...

You could use extensions but it might not look as good if it's any more than about 20mm a side (for example). Theoretically you can extend it with a bit of copper pipe and a compression fitting but again it will look rather crap.

Worth noting you can effectively use the rad valves as a drain point once the radiator is off the wall.
 
St0rmer66 said:
You could use extensions but it might not look as good if it's any more than about 20mm a side (for example). Theoretically you can extend it with a bit of copper pipe and a compression fitting but again it will look rather crap.
Click to expand...
The old rad is 1017mm and the new one is 831mm so a bit more than 20mm difference! The T junction is under the floorboards so can I add a 90 degree extension and then set the upright copper pipe at the right location. Would you recommend that I cut the pipe below the rad valve :eek: quickly fit a compression isolation valve and then take my time to fit the rest of the pipework?
 
Don't cut the pipe without taking the pressure out of the system first or you will get wet! ;). What I meant was close the radiator valve at both sides of the radiator, crack open the nut on the now isolated radiator and drain it off. It can then be removed leaving you with 2 open ends on the existing radiator valves which you can use to take the pressure out of the system. As long as you only have 1 open end at a time the beauty of a sealed system is that you can work with the rest of the system still full of water and only get a dribble of water coming out when you break into pipework. Just don't open more than one at once or air can get in one and then water comes out of the other! If you don't feel safe trying it then by all means drain the whole thing though.
 
Do the job slowly and take your time.

I would drain it down, run it below floorboard and up to new radiator, refill with inhibitor.

2 elbow above floorboard is a bodge job.

Daniel.
 
St0rmer66 said:
Don't cut the pipe without taking the pressure out of the system first or you will get wet! ;). What I meant was close the radiator valve at both sides of the radiator, crack open the nut on the now isolated radiator and drain it off. It can then be removed leaving you with 2 open ends on the existing radiator valves which you can use to take the pressure out of the system. As long as you only have 1 open end at a time the beauty of a sealed system is that you can work with the rest of the system still full of water and only get a dribble of water coming out when you break into pipework. Just don't open more than one at once or air can get in one and then water comes out of the other! If you don't feel safe trying it then by all means drain the whole thing though.
Click to expand...
!!Thanks!! When taking the pressure out of the system, do I let water out until I get a trickle? Is it important whether i relieve the pressure from the thermo valve or the other side?
 
stardanny said:
Do the job slowly and take your time.

I would drain it down, run it below floorboard and up to new radiator, refill with inhibitor.

2 elbow above floorboard is a bodge job.

Daniel.
Click to expand...
I agree!! I'll only do an elbow under the floorboards
 
Yukster said:
St0rmer66 said:
Don't cut the pipe without taking the pressure out of the system first or you will get wet! ;). What I meant was close the radiator valve at both sides of the radiator, crack open the nut on the now isolated radiator and drain it off. It can then be removed leaving you with 2 open ends on the existing radiator valves which you can use to take the pressure out of the system. As long as you only have 1 open end at a time the beauty of a sealed system is that you can work with the rest of the system still full of water and only get a dribble of water coming out when you break into pipework. Just don't open more than one at once or air can get in one and then water comes out of the other! If you don't feel safe trying it then by all means drain the whole thing though.
Click to expand...
!!Thanks!! When taking the pressure out of the system, do I let water out until I get a trickle? Is it important whether i relieve the pressure from the thermo valve or the other side?
Click to expand...

No it doesn't matter which side. Wait until a trickle or it stops... Then open it a bit more just to be sure it's all gone!
 
St0rmer66 said:
Close the radiator valve at both sides of the radiator, crack open the nut on the now isolated radiator and drain it off. It can then be removed leaving you with 2 open ends on the existing radiator valves which you can use to take the pressure out of the system. As long as you only have 1 open end at a time the beauty of a sealed system is that you can work with the rest of the system still full of water and only get a dribble of water coming out when you break into pipework. Just don't open more than one at once or air can get in one and then water comes out of the other! If you don't feel safe trying it then by all means drain the whole thing though.
Click to expand...
It worked when replacing the first rad. I removed a second rad and drained it whilst both valves are off. I opened one of the valves to reduce the pressure but the water is gushing into the bucket and it doesn't look like it's going to stop. Any advice?
 
Air must be getting in somewhere. Make sure you turned the new valves off on the first radiator you changed. Failing that you may just have to drain it, not all systems are the same unfortunately!
 
D

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