In article
, NT
writes
On Oct 23, 1:07*pm, fred wrote:

The whole object is to avoid heating the rest of the house.

I think the object is to pick the cheapest to run system

I'm sure the o/p now has enough information to make his choice.

Why would
this waste heat hang around until the evening? I expect the energy will
have dispersed to the ether long before then.

If you heat a house to 20 in the morning, and leave the system off
till 6pm, a good 80% of that heat is still retained indoors by then.

If you've ever had a home heated by storage heaters you'd know that
isn't the case.

Either way I don't see that as the main issue, I view it as bad practice
to design a system that will repeatedly short cycle a boiler. I designed
my system for a long slow burn to avoid the thermal stresses that
repeated cycling inevitably brings and I hope to reap the benefits of
this in a longer system life.

Is thermal cycling a major failure mode in boilers? I didnt think it
was.

The more you cycle something the shorter it lasts, cars, electronics,
whatever. If the ignition circuit of the boiler lasts for say a million
hits then the service life will be reduced by repeated over-cycling.

Besides that, the o/p's existing system does not currently support this
mode of operation requiring capital investment in redesign, controls and
rework of plumbing. It appears to me that he is looking for a simpler
fix than this.

wireless thermostat.

And the rest.
--
fred
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