C1 Solar Sensor Fault

I have a C1 too, and I recall something similar a while back. My heating was all over the place. Did the diagnostic tool specifically point to the solar sensor, or was it a more general HVAC error? It's worth checking all related sensors.

Thanks. The diagnostic report explicitly indicated a fault with the solar sensor circuit. When you had your issue, did the diagnostic tool also pinpoint the solar sensor, or was the error code less specific? Did replacing the sensor resolve it entirely, or were further steps needed?

Yes, in my instance, it was also the solar sensor that flagged up on the diagnostic. After the error came up, I booked it into the workshop. Turned out to be the sensor!

I appreciate you confirming that the solar sensor was the culprit in your case. Your experience has given me the impetus to proceed with replacing the sensor, or maybe inspecting the connector first. I will report back on the resolution. The projected repair cost is about 95€ at my local place.