BoilerFaultCodesIdeal 432 Fault Code
The Ideal 432 fault code means: your boiler has detected a fault with one of its internal temperature sensors, which is preventing the system from heating up safely.. It appears on 2 Ideal models in our database.
Technical description: NTC2 short circuit
What causes the Ideal 432 fault?
This fault occurs when the boiler's internal temperature sensor develops an electrical short, causing it to send an incorrect signal to the main control board. The most common reason is that the sensor has suffered internal failure due to age, or moisture has compromised the electrical connections between the sensor and the wiring harness.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Ideal models that show the 432 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Ideal 432 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