E501
FAULT CODE
Baxi
eBUS/Communication Fault
Medium Severity
Engineer Required
A communication fault between the boiler and a connected external controller (thermostat, zone control, etc.) over the eBUS data connection.
Step-by-Step Fix Guide
-
Step 1
Check all wiring connections between the boiler and thermostat/controller
-
Step 2
Turn the boiler off at the mains for 10 minutes then restart
-
Step 3 Engineer only
If fault persists, call a Gas Safe engineer to test the controller wiring
Gas Safe Reminder
Work on gas appliances must be carried out by a Gas Safe registered engineer. The steps above cover safe checks a homeowner can perform - any internal component replacement requires a qualified professional. If in doubt, always call an engineer.