BoilerFaultCodesIdeal 84 Fault Code
The Ideal 84 fault code means: your boiler is trying to start up but is failing to create the spark or flame needed to heat your water.. It appears on 2 Ideal models in our database.
Technical description: Power to PCB 37 but burner pressure incorrect or zero
What causes the Ideal 84 fault?
This fault occurs when the boiler's control system attempts to light the burner but cannot detect a stable flame. It is usually caused by a component failure that prevents a spark from being generated, or a blockage that stops gas from flowing into the combustion chamber.
This fault can appear more frequently during the first cold snap of autumn when old electrodes or gas valves struggle to operate after sitting idle through the summer.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Gas Safe Register →Ideal models that show the 84 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Ideal 84 fault code information on this page is sourced and cross-checked against the official Ideal service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026