greenstar junior DHW problem

[snoopy8888]

CH is fine but no hot water. I am leaning toward the flow sensor.
Anyone know the voltage between the 3 wires black, yellow and red from the sensor ?
Much appreciated and thanks in advance.

 

[ambrosia]

i think you do it at the board and its 24v, off the top of my head i think it was yellow and black but youll have to play about with it, only 3 wires, experiment with the wires and see if you get a change when you turn the tap on

 

[AlexGas]

Flow Sensor Test
Replace control board if: 5V is not across the red and black cables.
1.5V-3.5V is across the yellow and black cables (with water flowing). Otherwise replace flow sensor.