Hot water secondary return - plastic pipe?

[fezster]

A quick question on secondary returns for HW. I remember reading somewhere that you cannot use Hep2o for a secondary return. Could someone explain why?

I was thinking about this the other day, and central heating circuits are fine with Hep2o, so why not HW circuits? Surely both pump hot water around at similar temps. Or does it have something to do with fresh water causing the problem?

 

[fezster]

Ignore! Just found this thread in search:

http://www.ukplumbersforums.co.uk/plumbing-forum/55169-speed-fit-secondary-return-3.html


Very useful for anyone else thinking the same.