Central Heating OK but no DHW

[BinB]

Another Ideal isar Boiler problem, I have no dhw, but the Central heating works OK, I have found the problem to be the Honeywell Diverter Valve Actuator, if I remove the head the plunger comes out of the body (the default seting) and I get DHW, how can I check that the motorised part of the valve is working, or is the problem with the pcb not supplying power to move the valve.
Please can any one help.
binb

 

[Kristoflampie]

Basically the 3 pin plug that detachs the actuator from the board has 240v on 1 and 2 or 2 and 3 depending on if its dhw or heating . If it changes in response to the boiler swopping between heating and hot water then its the actuator. Down to experience, its the actuator because when the PCB goes usually nothing works and the boiler is dead........

 

[BinB]

Thanks for that, but the electric wires that connect the acutator socket to the board has 4 cables and I don't know which one's to test to get the motor to run, and it's late now so I will check tomorow, Monday.
Thanks again,
BinB.