High
F33 on Ferroli Econcept 100

Your boiler's air intake or exhaust monitoring system has lost its connection, preventing the unit from starting 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.

Technical description

Resistor at terminals 7-8 of connector X5 not connected

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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Related fault codes

F05View →F37View →

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