"Pandora" wrote in message
...

Dave Plowman (News) wrote in message
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So this wouldn't be a direct replacement for a cylinder stat? But
integrated into some form of microprocessor control?

Yes, sorry if this was unclear. Some boilers have a facility to
continuously
vary their output..

No need in cylinder re-heat with a quick recovery coil. You want the boiler
to dump all its heat ASAP into the cylinder and then shut off when up to
temperature.

Most modern boilers have some sort of burner modulation.