drain cock

[tonyten]

obviousley a drain cock needs to go on the lowest point of your system, but does it matter which pipe you put it on in a combi boiler, eg ,flow, return,etc.

 

[Nige F]

NO, just make shure you get a heavy pattern one and disassemble it before you solder it into the pipework.

 

[ollski]

no just the lowest point or each lowest point if you have a series of drops.

 

[chrishutt]

No, it doesn't matter since the other pipes will drain via connections through radiators. However it might be good practice to provide drain points on both, in case only one side needs draining.

I would not necessarily agree that the lowest point is always best. More important is that the drain point(s) are accessible and where spillages are less of a problem (e.g. over tiled kitchen floor). Small amounts of water left in low points can be blown out if necessary.

 

[ChrisR]

Put one on each pipe (F&R) and take them to outside if at all possible, with the final connection to the drain cock on a compression fitting. It might sound o-t-t, but when you have to do a powerflush, it's an absolute dream compared with the alternatives. There are always splashes which it can be hard to catch completely.
Tip- if you make the bits of pipe under the floor going to the dc's plastic not copper, you can make the holes in the wall just big enough to be able to shove the dc's back almost out of sight.
If you really want to do it properly use these:

edited to add the underlined bit!

 

[Nige F]

Methinks you`ve done a bit of commercial, ChrisR

 

[gstens baxi]

Chris r on commision

 

[ChrisR]

Not really no - so I suppose I have to make a smart*rse comment about just liking to do things in an engineering sort of way...?