E321
FAULT CODE
Main Heating
Hot Water NTC Fault (Eco Compact)
Medium Severity
Engineer Required
On Main Eco Compact boilers, E321 indicates a hot water thermistor fault.
Step-by-Step Fix Guide
-
Step 1 Engineer only
Call a Gas Safe engineer to test and replace the DHW 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.