which is flow & return?

[IA76]

Hi

If every rad in a house has been removed and the pipes have been blocked off with end stops where the valves would have been how do you test which is the feed and which is the return pipe at each rad.

The boiler is working fine.

Thanks

 

[chrishutt]

Why do you need to know? Most TRVs are bi-directional, so it doesn't matter which end they go on.

 

[nstreet]

Normally the pipe thats get hot first would be the flow, but as all of your rads pipes are capped off, there won't be any flow except around the bypass. As CH suggests most if not all moderen trv's are bidirectional so it won't really matter which end they go on.

As you do each rad, you could put a loop of hose between the pipe ends and see which side gets hot first. Its a wet and messy job though, as you dont want to keep draining down between each test. Or loop all of the rads at once.

 

[IA76]

Hi

I wanted to know for TRV's but if you say most TRV's are now bi-directional then it's irrelevant

Thanks