High
125 on Baxi EcoBlue System

Your boiler has detected that hot water is not flowing around your heating system correctly, which is causing it to shut down to prevent 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

R Circulation Fault (Primary)

From this model's manual
Verified against the Baxi Ecoblue System installation & service manual, page 64.
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 the water temperature is rising too quickly because it isn't being moved away from the burner. The most common reason is a seized or failing pump, though it can also be caused by an airlock or a blockage in the system preventing the water from flowing. For your safety, the boiler shuts down immediately to prevent the heat exchanger from reaching dangerous temperatures.

This fault is frequently seen at the start of autumn when heating systems are turned back on after months of inactivity, which can cause the internal pump to seize.

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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