Low
d6 on Alpha Eco

Your boiler is having trouble communicating with the outdoor sensor that measures the outside temperature to adjust your heating automatically.

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.

What the manual says

Manufacturer manual

External weather compensation probe temperature (value flashes if negative) °C

From this model's manual
Verified against the Alpha Eco installation & service manual, page 23.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

Engineer required

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

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Avoid the next call-out bill

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