Good point about the flange. I've been researching these. I bought a 22mm
surrey flange from PlumbCenter, only to find it doesn't fit on the top of my
"Superlag" cylinder (from 1991). So I plan to make my own flange - I've
bought a 22mm/22mm/22mm Tee and a 22mm/15mm reducer. The T goes on top of
the cylinder. The reducer goes on top of the T. I can file the reducer's
insert limiter rim so I can push 15mm pipe all the way through it, and
through the attached 22mm T (so that it goes under the surface of the water
of the cylinder). It's not a surrey flange - the 'air free' and normal hot
water positions are exchanged. But a coupleof elbows and I can sort that.

You can hear the air in the cylinder if you bang it - and your can hear it
coming out the shower head. But I'm more concerned that without a flange the
pump will suck air down the expansion pipe, rather than out the cylinder!

I haven't ordered the shower pump yet, but I'll go for a Stuart Turner one.
Just 1 bar (that's 30ft head - plenty for me). I want a brass pump -
something that won't split open and flood my house out when I'm at work. The
plastic pumps from local DIY stores look too flimsy - I don't trust them -
the fittings look like garden hosepipe connectors.

Alistair.



"Christian McArdle" wrote in message
. net...
I was thinking if there is pump that you could add to the hot water
supply to increase the speed of the hot water flow. This is for an
open vented system.

Yes. It is called a single impellor shower pump. If you're pressurising
the
whole house with it, get a good quality heavy duty type such as a Stuart
Turner Monsoon. Depending on the layout of the system and myriad other
factors, you may find the increased flow rate leads to air being sucked
down
the vent tube. If this happens, and there is no obvious culprit like a
half
closed feed valve to the cylinder, you will need to install a flange on
the
system (or you might find turning the pump down fixes it). The flange will
normally eliminate the air effect provided it isn't too bad, although it
will effectively reduce the size of your cylinder slightly as the top of
the
cylinder will become "dead" space.

Christian.