ECOtech 418 problem

[Robert Tyrrell]

I got called to deal with a breakdown on this boiler and I'm stumped.
It fires on the hot water no problem but for the heating it doesn't do a thing.
I did note that the Salus wireless room stat was faulty (No signal to the receiver) so I swapped it out with a DT92E but it still doesn't work on the heating.
I called Vaillant and they reckon it's the 3 way valve at fault but I'm not sure about that and didn't have time to check it so I'm going back on Monday but wondered if any of you had a quick and easy method of testing the valve

 

[Riley]

I'd say control issue mate. Three port Likely

 

[Jay Jay]

The 418 model is a heat only boiler so its dictated by controls making it come on/off if you got hot water then no boiler issue, if 2port check voltage on brown wire with room stat turned on and if 3port check voltage on white wire and also grey wire.
Hope this helps

 

[Aquazone]

If it's a 2 port, should be 240v on brown wire with all controls calling.
If it's a 3 port with CH only on clock and room stat up - there should be 240v on white and grey

If there is the voltages above and the motor moves but nothing happens then switch has failed and new actuator req'd. If motor doesn't move with above voltages then you could try a new syncron motor.

 

[Robert Tyrrell]

Thanks for the help guys, just confirms what I thought really. I'd already checked voltages on the white & grey wires (3way valve) and it looks like it's the actuator gone but what I really wanted to know is of there was a simple tell tale that would help to diagnose the problem without having to check voltages.
They're simple enough I suppose but I would like to see a little LED on the valve to show correct operation; White LED for correct voltage to white wire, Blue LED (Grey is difficult to see in a cylinder cupboard) for the grey wire and a green LED for correct operation of the valve, or they could have a Green LED for the actuator, and a Blue one for the motor.
Probably a bit too much to expect eh?