Low Warning
92 on Viessmann Vitodens 333

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.

Monitor it

This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.

Technical description

Control mode - Solar: Collector temperature sensor shorted out

What causes this 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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