BoilerFaultCodesViessmann 92 Fault Code
The Viessmann 92 fault code means: your boiler’s solar heating panel sensor has a wiring fault, meaning the system cannot correctly read the temperature of the water heated by the sun.. It appears on 7 Viessmann models in our database.
Technical description: Control mode - Solar: Collector temperature sensor shorted out
What causes the Viessmann 92 fault?
This fault occurs when the electrical circuit for your solar roof panels is broken or compromised, preventing the boiler from receiving a temperature reading. The most common reason is that the sensor probe has failed internally or the wiring has been damaged by pests or extreme weather exposure. In some cases, the connection at the boiler's control board may have simply become loose or corroded.
This fault is more common in summer, as higher temperatures on the roof can accelerate the degradation of the sensor lead or highlight a failure when the solar pump attempts to run.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Gas Safe Register →Viessmann models that show the 92 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Viessmann 92 fault code information on this page is sourced and cross-checked against the official Viessmann service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026