Veissman 200 Weather Sensor malfunction?

[MrSaurus]

I have had Viessman Vitoden 200 for ~6 years. Have had almost no issues with it, works brilliantly. However the central heating has stopped working in the last couple of weeks. The boiler seems fine, no fault code, green light, hot water good etc. The only problem I can actually see is that the external weather temp sensor is always reading too high. I’ve checked the display screen on the boiler many times at different times of the day and night and the reading is always too high, between 22c and 30c outside. It’s on a north facing wall and has always been accurate in the past. So I assume the sensor has broken. Is that a fair assessment? Is this a common problem with this model? Is there any way I can reprogram the boiler to bypass or workaround the temp sensor? Any help or advice greatly appreciated. Thank you.

 

[Johntheo5]

If its not preventing the boiler from firing you might be able to change to the steepest heating curve which may then call for 40/50C flow SP, as a temporary measure.

 

[Johntheo5]

This may help......

Viessmann Vitodens 200-w - initial impressions

Hello I had the Viessmann 200w installed recently and, as I wasn't able to find out loads from the forums in advance, thought I'd post a few initial impressions and 'gotchas' here that tripped up the installers a little as part of the installation. This was the most recent version of this boiler ...

forum.buildhub.org.uk