Draining a central heating system

[SALL2009]

Hi need to drain a heating system. The boiler is a Baxi boiler. I need to remove a upstairs radiator and then reinstall in same place within a few days. Can someone tell me how to drain the system or any other ideas to achieve what I'm trying to do.

 

[kevplumb]

first look for View media item 14822
switch boiler off

tie up ballvalve open drain tap then open a rad bleed valve

if its a sealed system there is no ballvalve

 

[TicklyT]

Providing you aren't altering any pipework, you should be able to drain just the radiator you are removing.

Close the valves either end of the radiator (or fit decorators cap on thermostatic valve). note down how many turns (and fractions of a turn) it takes to close the lockshield valve.

Place paint tray or dustpan under one valve to catch the water, loosen the union nut between the valve and the radiator and release the bleed screw.

If more than a couple of bucket fulls of water comes out, a valve is probably leaking. Follow Kevplumb's method to drain the system.

When water stops flowing, loosen the other union, expecting just a few drops of water. Remove radiator but beware of sludge in the bottom of the rad. - once spilt, it's impossible to get it out of carpets - a couple of corks may be useful.


To reconnect, fit and tighten the unions, turn on the valves and bleed the rad.

For a sealed system, re-pressurise and bleed again until rad. is full of water.

 

[SALL2009]

Is a tool required to open the drain tap? or normal socket will open it?

 

[45yearsagasman]

Sall, No need to drain the sysem if all you want to do is to remove and replace a rad.Follow TicklyT's advice.

 

[SALL2009]

If I go the suggestion from TicklyT.

I understand I would need to turn of the two vales on the sides of the radiator.


I'm a bit confused what this means, "note down how many turns (and fractions of a turn) it takes to close the lockshield valve. "

Is it not meant to be turned till it can't be turned any more and then turn all the way in the opposite direction to open the valve?

 

[transam]

Perhaps you might be best advised to get some assistance ? from someone ? who has done this before ??

 

[SALL2009]

Yeah I was planning on using a central heating engineer I use, but its Sunday tomorrow and the radiator is holding up some work that I have planned for tomorrow.

I'm good with normal plumbing connection etc. I’ve just never attempted anything to do with central heating, so it seems a bit daunting. But I think I'll have a play tomorrow. It seems quite straight forward.