Fitting a drain valve

[jaybeex2]

Im in the process of installing a full central heating system to an old terrace property, when it comes to the drain valve, im assuming its best fitted on the lowest point, but is it better on the flow or return side?

Regards
John

 

[Armo74]

Doesn't really matter which side but is advisable to fit one on each rad downstairs.
Screwfix do a good pegler terrier lockshield with built in drain cock which also enables you to drain just the rad if you close both valves there only about £8.
There are also some cheaper valves with built in drain cocks.

 

[jaybeex2]

Thanks Armo they look neat!
Is it ok not quite being at the lowest point on the system or are am i being too picky?

 

[Armo74]

Depending on floors and pipe runs the lowest point tends to be below floor level which obviously isn't very practical.
Unless you have a leak or want to move a rad it isn't very often that you need to work on the pipework below the rads.

 

[buck51]

You should still fit a drain off at the lowest point on both the flow and return to avoid future problems