"Set Square" wrote in message
...
I currently have a Y-Plan heating system. The pump and 3-port valve are both
in the airing cuboard with the 3-port valve sitting more or less on top of
the pump. The outlets from the 3-port valve - one to the coil in the
cylinder and the other to the radiators - are horizontal, and are level with
the top indirect coil connection, about half way up the cylinder.

The 3-port valve is showing its age and will soon need replacing. I would
like to convert to an S-Plan system by replacing the 3-port valve with two
2-port valves plus an automatic by-pass. I would also like to insert some
full-bore lever valves to make it easy to isolate each component for
maintenance.

I cannot do this without changing the layout somewhat. There is not enough
horizontal pipe either side of the 3-port valve (to be repaced by a tee) to
insert 2-port valves. So I would like to extend the pipework by a foot or so
above the current level, tee to 2 horizontal branches, and then come down
again vertically with a 2-port valve in each vertical drop. I would, of
course, put a vent pipe with bleed screw at the hightest point.

Can anyone see any problems with this?

TIA.

Cheers,
Set Square


The fed to the coil in the cylinder doesn't really need to enter at the bottom
connector you know, so you could lift the branch from the pump higher and place
the zone valves on two different levels all together. That way you can keep the
branch to the rad' circuit where it is, and only swap round the heating coil so
it runs the other way. One TEE and a couple of elbows would do it.