On 04/03/2018 17:54, TheChief wrote:
Hi Guys

I am having problems with piping to radiators which has been run
in plastic pipe.
I suspect that the poor performance of the rads is partly down to
15mm pipe being used over a fair length and teed to two rads.
There is also some crud floating around which is blocking the
feed pipe, or restricting the flow.
So I was looking at increasing two 15mm runs to 22mm to help the
flow and decrease the likelihood of future blockages.

Contemplating this leads to the type and reliability of different
joint types. The current 15mm plastic runs connect to the
original 22mm copper mains via copper reducing tees/stub pipes
and Hep20 push fit couplers. I have not had any problems with
these.

What are the group's current thoughts on push fit Vs compression
on plastic pipe, particularly 22mm?
Some recent posts suggest that Hep20 fittings are not as reliable
as previously.

Thanks

Phil

Assuming it is a pumped system rather than natural circulation, and a
normal sized house without "Stately Home" run lengths. I'd expect 15 mm
to be plenty, and 22 mm overkill. Perhaps you could tell us the size (or
BTU rating) of the radiators, and the length of the run, then someone
could give more definitive advice. Blockages are possible but as another
poster said, has the system been balanced?