E321
FAULT CODE
Potterton
Hot Water Thermistor Fault
Medium Severity
Engineer Required
The hot water temperature thermistor has a fault — applies to store/system boilers with a hot water cylinder.
Step-by-Step Fix Guide
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Step 1
Turn off the boiler
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Step 2 Engineer only
Call a Gas Safe engineer to test and replace the hot water 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.