BoilerFaultCodesWarmhaus E42 Fault Code
The Warmhaus E42 fault code means: one of the buttons on your boiler's control panel has become stuck or is malfunctioning, preventing you from changing settings.. It appears on 1 Warmhaus model in our database.
Technical description: Error with pushbutton
What causes the Warmhaus E42 fault?
This fault occurs when the boiler's control board detects that a button is being held down continuously for a long period, usually more than one minute. This is typically caused by a button physically sticking behind the plastic casing or a micro-switch failure on the internal circuit board. It essentially prevents the boiler from receiving new commands to ensure the settings don't change unexpectedly.
DIY fix possible
Check if any of the buttons on the front panel are physically stuck or pressed in.Gently press and release each button several times to see if they click back into place.Switch the boiler off at the fused spur switch, wait 30 seconds, and turn it back on to reset the display.
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Gas Safe Register →Warmhaus models that show the E42 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Warmhaus E42 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