High
E302 on Navien LCB700

Your boiler has stopped working because the water pressure inside the system has dropped too low to operate safely.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

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

The pressure is lower than the minimum pressure set (0.4 bar by default)

From this model's manual
Verified against the Navien Lcb700 installation & service manual, page 67.
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 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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