High
E03 on Potterton Powermax HE

Your boiler has shut down because it is unable to safely discharge exhaust fumes or has detected that the flue system is overheating.

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

What the manual says

Manufacturer manual

Flow temperature abnormally high. Check pump, 3-way valve & CH system pressure. Replenish system, adjust pump speed & bleed air

From this model's manual
Verified against the Potterton Powermax He installation & service manual, page 39.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

What causes this fault?

This fault occurs when the boiler's internal sensors detect that harmful exhaust gases are not being cleared away correctly or that the flue is getting too hot. The most common reasons include a blockage in the flue pipe, a failing fan that cannot push the fumes out, or a sensor that has become faulty and is giving a false reading.

This fault can sometimes occur during period of high winds, as strong gusts can create back-pressure in the flue that interferes with the air pressure switch.

Engineer required

This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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