BoilerFaultCodesMain E127 Fault Code
The Main E127 fault code means: your boiler has detected that there is not enough water flowing through the system, meaning it has switched itself off to prevent overheating.. It appears on 1 Main model in our database.
Technical description: Circulation fault (dry fire)
DIY fix possible
Check your system pressure gauge; if it is below 1 bar, locate the filling loop under the boiler.Open the filling loop to allow water into the system until the gauge reads between 1 and 1.5 bar.Close the filling loop tightly and reset the boiler using the reset button or dial.
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Gas Safe Register →Main models that show the E127 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Main E127 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 27 April 2026