On 15/05/2021 11:27, Theo wrote:

I never investigated but I imagine there was just on/off control for the
boiler (gas valve only, since there was an always-on pilot that had a piezo
spark-button to relight it if it went out), and an additional time clock
output that was in series with a thermostat to run the pump for the heating.

How was the boiler turned off in this system, when the thermostat said the
house was hot enough and so was the water? If the heating called for heat
and the hot water was up to temp, surely that would overheat the water?

https://assets.danfoss.com/documents...6en-GB0201.pdf

Were the common programmers of the time


--
Adam