In an earlier contribution to this discussion,
Malcolm Reeves wrote:


That's not my point, which was pump overrun is what you need to get
rid of boiler excess heat.

Bypass does not figure, except that you need to allow flow. You could
have an always on rad for that.

You may not want this in the summer! Consider an S-Plan system with the
heating zone valve firmly shut, and the boiler running to heat the hot
water. When this is satisfied, the HW zone valve closes and the boiler stops
firing. BUT you still need some flow during the pump over-run period to stop
the boiler from tripping. Where can this flow go if you don't have a
by-pass?
--
Cheers,
Set Square
______
Please reply to newsgroup. Reply address is invalid.