E33
FAULT CODE
Johnson & Starley
Return Thermistor Fault
Medium Severity
Engineer Required
The return temperature sensor has a fault - open circuit, short circuit, or wiring issue.
Step-by-Step Fix Guide
-
Step 1 Engineer only
Call a Gas Safe engineer to test and replace the return thermistor
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.