I'm thinking of using a Heatmiser PRT/HW programmable stat
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either in addition to (or as a full replacement of) my existing programmable controller (it's LCD display having died)All their wiring diagrams show the use of a motorised valve to control h/w and c/h, but my system is gravity h/w and pumped c/h, I phoned them and they were less than convincing that the PRT/HW could entirely replace the existing controller, I wonder if I can do it using an external SPST/CO relay to negate the c/h pump supply when h/w output is switched on? I'll probably email their tech dept to see if that elicits a better response, but anyone here already done it or think/know if it can work with or without a relay? Can I still incorporate a h/w tank stat too?
TIA ...