Boiler Fault Code 18-19

Also written as 1819 — same fault.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026

Fault code 18-19 appears across 1 boiler brand and 3 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler has lost water pressure or cannot detect enough water to operate safely, causing it to shut down to prevent damage. (As reported on Remeha Gas 350)