On Tuesday, 3 November 2020 at 23:24:19 UTC, wrote:
On 03/11/2020 19:08, Harry Bloomfield wrote:
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Modern boiler have separate temperatures for CH to HW.
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Really? A combi may have this but are there any system boilers with it?
If so, how is it signalled?

Two different "call for heat" signals. One for CH, one for HW. My Viessmann has this, and it works very well with the W-plan I have.