BoilerFaultCodesWarmhaus E37 Fault Code
The Warmhaus E37 fault code means: your boiler has detected that the electrical supply coming into the unit is too weak for it to run safely.. It appears on 1 Warmhaus model in our database.
Technical description: Low voltage error – voltage required for operation is too low.
What causes the Warmhaus E37 fault?
This fault occurs when the electrical current reaching the boiler's internal components falls below the minimum level required for safe operation. It is often caused by a problem with your home's main electricity supply, a faulty power cable, or a failing internal control board that can no longer process the incoming power correctly.
This fault can sometimes occur during peak winter months if the local electrical grid is under heavy strain, leading to 'brownouts' or temporary drops in voltage to your property.
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 →Warmhaus models that show the E37 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Warmhaus E37 fault code information on this page is sourced and cross-checked against the official Warmhaus service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026