BoilerFaultCodesIdeal ERROR CODE 6 Fault Code
Also written as ERRORCODE6 — same fault.
The Ideal ERROR CODE 6 fault code means: your boiler is having trouble measuring the temperature of your hot water, likely meaning you won't have any hot water available.. It appears on 2 Ideal models in our database.
Technical description: DHW THERMISTOR FAULT
What causes the Ideal ERROR CODE 6 fault?
This fault occurs when the sensor responsible for monitoring your hot water temperature has failed or is sending incorrect electrical signals back to the main control board. Over time, these sensors can degrade due to constant heat cycles or internal corrosion, leading the boiler to shut down for safety because it can no longer regulate water temperature correctly.
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 ERROR CODE 6 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Ideal ERROR CODE 6 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