Viessmann Combi no domestic hot water

[Plumber69]

Vitodens 100-w WB1B.
The heating works fine. Turn on tap and faucet symbol shows on screen. But no ignition for domestic hot water. The pump is running and you can see the diverter valve switch over. After that just runs cold and no error.

If I unplug a cable from the outlet temperature sensor it will fire up for 30 seconds and error out. The book says to test resistents on the sensor, but I am getting nothing. I pulled it out and it has a build up of rust on it which I was unable to clean off.
Is this most likely my issue?

 

[John Gayewski]

Vitodens 100-w WB1B.
The heating works fine. Turn on tap and faucet symbol shows on screen. But no ignition for domestic hot water. The pump is running and you can see the diverter valve switch over. After that just runs cold and no error.

If I unplug a cable from the outlet temperature sensor it will fire up for 30 seconds and error out. The book says to test resistents on the sensor, but I am getting nothing. I pulled it out and it has a build up of rust on it which I was unable to clean off.
Is this most likely my issue?

Sounds like it's the issue if your testing it and it fails.

 

[Sponsor]

 

[Fitter30]

Sensors have to be disconnected from board. T1,2,3,4 and flue temp should be the same sensor. Page 82 has sensor readings
https://www.google.com/url?q=https:...gQFnoECAoQAg&usg=AOvVaw2rXYTUDMhWhGnnyByxYMwU