I've got a Y-plan system. My room thermostat can call for CH ON or HW ON or obviously both ON at the same time. But it can't call for HW OFF (other than the absence of HW ON). Which means that the mid position valve would always be in either the mid-position or CH only position. With the room thermostat came a wiring diagram showing how a relay connected to both live and a cylinder stat could provide a separate HW ON or HW OFF signal.
Any suggestions to What relay could provide this function for me?
Any suggestions to What relay could provide this function for me?