205
FAULT CODE
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Heating Supply Thermistor Fault
Medium Severity
Engineer Required
The heating supply (flow) thermistor has an open or short circuit fault. The boiler may auto-reset.
Step-by-Step Fix Guide
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Step 1
Allow auto-reset if boiler attempts it
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Step 2 Engineer only
If fault persists, call a Gas Safe engineer to test and replace the flow 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.