High
On Off On Off on Potterton Promax FSB 30HE

Your boiler has shut down because water intended for your drain is backing up and has triggered a safety sensor.

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

Condensate pump level switch activated for longer than 3 minutes - boiler locks out.

From this model's manual
Verified against the Potterton Promax Fsb 30he installation & service manual.
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 internal tank that collects waste water becomes full and cannot empty itself properly. The most common reasons are a mechanical failure of the condensate pump or a blockage in the thin plastic discharge pipe leading away from the boiler. To prevent an internal flood, a safety sensor triggers and shuts the system down until the water level drops.

This fault is particularly common during freezing winter temperatures, as the external portion of the waste pipe can freeze solid and prevent water from leaving the pump.

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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