replacing a radiator!!

2 Jun 2005
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United Kingdom
I want to replace a radiator but would like to know step by step of how to drain the system..

*For some reason I have two tanks up in the loft one big one small no drain cock but I've been told to tie the floats arms to a batten...?

*I have an old boiler with all the lagging round in the airing cupboard, there is a drain valve which i can connect a hose to but, there's also a drain valve on the radiator downstairs which i want to replace...! Which drain valve do I use to drain the system?

many thx


ps I want to impress the wife!! :)

It's not just the radiator i want to replace but also the vavles..
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the big tank feeds the secondary circuit, which is the one which give you hot and and cold at the taps, and has a drain on the pipe at the bottom of the cylinder. You don't need to touch any of this to do the rad. The small tank feeds the rads and boiler, so you stop this filling and drain your rad. tHis also empties the boiler so you must turn it off, first.
if the water comes out black you should refill, add some cleanser, eg Fernox/Sentinel and repeat until it's clean. when all done don't forget to add inhibitor at the end.
I wonder why you're changing the rad, you haven't said what the problem is.
Why drain the system if you're just replacing a radiator with a new one?


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