In article , IMM wrote:


"IMM" wrote in message
...

"Mike Clarke" wrote in message
...

It is a modulating boiler and has
an internal bypass so it works OK but
I am conscious of the energy wasted
when all the TRVs are shut as the
boiler cuts in from time to time
to keep the water circulating inside
itself up to temperature.

Ah! Simple. Just fit a flowswitch on the return. When all TVRs are
closed
the boiler will protect itself by opening its own by-pass and the flow
switch will simply turn the boiler off as there is no flow.

What is all the fuss on this thread. My, oh, my!

Just re-read what I wrote. To expand. Use an external by-pass and
flowswitch and a timer to switch back on to check if there is still flow
(TVRs opening), if no flow then if immediately switches off. If flow it stay
on until the flowswitch cuts in again.

But it shouldn't switch off immediately, we'll need a few seconds for
the flow to build up. So we're talking about a bit of custom timer logic
here or a couple of cascaded timeout switches, probably getting as
complicated as previous ideas.

--
Mike Clarke