Help Required - Vaillant Ecotec Pro 28

[jacknicmeg]

Hi Mickyg,

Have done as requested and used the multi-meter. Touched the two pins and it made a circuit.

Tried to switch on the boiler with the pins disconnected (should this be open circuit) and boiler still shows same fault, s10.

Still looks as if it calling for the hot water?

Help?

 

[mickyg]

no you misunderstand. test the resistance across the 2 pins using the multimeter. Set your multimeter to ohms reading. test across the 2 pins you see what ohms reading there is. should be between 2 and 12k ohms.

 

[jacknicmeg]

Hi Mickyg

So as requested I have checked the resistance using a Robin Digital Multimeter Model OM 840.

Set the switch to the following setting on Ohms and here are the results:

Switch on 200, result = 0 (zero)
Switch on 2k, result = 0 (zero)
Switch on 20k, result = 12.038
Switch on 200k, result = 12.08
Switch on 2m, result = .0120
Switch on 20m, result = 0.012

Sitting like a coiled spring awaiting your reply!

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[Softus]

Switch on 20k, result = 12.038

Therefore Agile was correct.

 

[jacknicmeg]

Agreed - but where do i go from here!

So, diverter valve or PCB or anything else?

 

[Softus]

Agreed - but where do i go from here!

Since you agree, you merely do the thing that Agile recommended/recommends.

 

[mickyg]

yep looks like its not that. As i previously said, it needs to be completely open circuit to cause the peculiar fault I've had before, and yours appears to be spot on. By the way does turning off the preheat make any difference?
Also now you have checked one NTC you may aswell check them all, they should all be roughly the same with the boiler cold.
Process of elimination with strange faults!
The aqua sensor can be checked electrically, your looking for 5 or 0vdc between red and earth with the tap off. and 2.5vdc between green and earth with tap on.

 

[doofusme]

Hi all

My daughters boiler has exactly the same fault, was there a conclusion to this thread?????

Best regards and hello

Phil

 

[Agile]

You should start your own thread explaining exactly what you model and problem is.

Tony