BoilerFaultCodesIdeal 30 Fault Code
The Ideal 30 fault code means: your boiler has detected an issue with the electrical power supply to the unit while it was running.. It appears on 5 Ideal models in our database.
Technical description: Maximum difference between T1 and T2 exceeded
What causes the Ideal 30 fault?
This fault occurs when the boiler detects an unstable electrical signal or a sudden drop in voltage while it is firing. It is usually caused by a loose connection in the internal wiring, a failing control board, or an issue with the electrical circuit providing power to the unit.
DIY fix possible
Check if other appliances in your home have power.Ensure the boiler's fused spur switch is fully turned on.Reset the boiler by following the instructions on the display panel.
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A cover plan would handle faults like 30: no call-out fees, no surprise bills.
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Ideal models that show the 30 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Ideal 30 fault code information on this page is sourced and cross-checked against the official Ideal service / installation manuals for each affected model.
- Ideal Logic Max Combi 2 manual (PDF)
- Ideal Logic Max Heat 2 manual (PDF)
- Ideal Maximiser SE manual (PDF)
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026