radiator valve drain off

[crooner]

Hi, i have no drain off on any of the radiators downstairs,so would like to fit a valve with drain off, but don't know which of the 4 radiators to fit it to, can i fit it to anyone of them
i have a combination boiler upstairs with 8mm microbore pipe coming from manifold's going to radiators

 

[xr4x4]

You need to fit it to the lowest point on the system, or all the lowest points on the system.

 

[Armo74]

As already stated ideally they could all do with them on. You can also get ones that allow the radiator to be drained on its own.

 

[crooner]

thanks paul , as all the downstairs radiators are about the same distance from the floor give or take a inch or so , will I have to fit a drain off to every radiator downstairs

 

[CBF]

you will have drops to every rad downstairs so if you only fit one then it will only drain that rad & the ones upstairs leaving the other 3 rads & their pipework downstairs still full, change all the locksheild rad valves downstairs for ones with built in drain offs

 

[crooner]

I was wondering as the ground floor of my house is 16 inch above ground level, if I only fitted 1 drain off with hose attached going outside down the steps to ground level , would that 16" be enough to completely drain the system
to save me fitting drain valves to all downstairs radiators

 

[crooner]

you will have drops to every rad downstairs so if you only fit one then it will only drain that rad & the ones upstairs leaving the other 3 rads & their pipework downstairs still full, change all the locksheild rad valves downstairs for ones with built in drain offs

from this reply even as I said I can drop a drain hose 16" it looks to me that the other 3 radiators will still be full of water, so looks like I will follow
advice & fit built in drain offs to all radiators downstairs
thanks to all for your help

 

[xr4x4]

It depends on if your downstairs radiators have pipe drops from the ceilings or are on a downstairs curcuit.

If on single pipe drops, each rad/curcuit needs drain offs to drain that curcuit.

If on a downstairs curcuit, normally you only need one drain of at the lowest point and that doesn't need to be on or near a rad, although easier to find for future owners/plumbers.