Low Warning
OUTDR on Grant Vortex

Your boiler has lost connection with its outside temperature sensor, which means the heating might not adjust correctly to the weather.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

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

Outdoor sensor short / Outdoor sensor open

What causes this fault?

This fault occurs when the electrical signal between the boiler and the external sensor is broken or distorted. The most common reason is water ingress or corrosion inside the sensor housing on the outside wall, or damage to the cable caused by gardening accidents or pests.

This fault is more common during autumn and winter when heavy rain or freezing temperatures can expose weaknesses in the sensor's weatherproofing.

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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