Halstead Finest

[ChrisR]

Changed the dhw diapragm, which had a small split. DV moving smartly. Customer reports that the HW only works if the CH is on.

So.... DHW flow switch switch itself (only 2 wires) or pcb - am I missing anything?

 

[cozzmic]

Hi Chris,
Check for 0volts dc across pins 23 and 24 if 5 volts is present across these pins check the flow switch and wiring. If 0 volts check the HW thermister and wiring, if its ok replace the PCB.
Hope this may help
Cozzmic