BoilerFaultCodesMain 30 Fault Code
The Main 30 fault code means: your boiler is simply performing its normal startup routine after being switched on or restarting after a power cut.. It appears on 2 Main models in our database.
Technical description: Power On
DIY fix possible
Wait a few minutes for the boiler to complete its internal startup sequence.If the boiler remains on this code for more than 10 minutes, turn the power off at the fused spur.Wait 30 seconds and turn the power back on to see if it clears to a normal operating temperature display.
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Main models that show the 30 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Main 30 fault code information on this page is sourced and cross-checked against the official Main service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026