BoilerFaultCodesPotterton E83491 Fault Code
The Potterton E83491 fault code means: your boiler's internal clock and timer settings have lost power because the backup battery inside the control panel has failed.. It appears on 1 Potterton model in our database.
Technical description: Programmer Battery
What causes the Potterton E83491 fault?
This fault occurs when the small backup battery soldered onto the boiler's internal control board finally runs out of charge. Much like a CMOS battery in an old computer, its job is to save your heating schedule during a power cut, but over many years of use, it eventually loses the ability to hold power. When this happens, the boiler can no longer remember your timer settings if the mains power is switched off or interrupted.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Gas Safe Register →Potterton models that show the E83491 fault code
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Source
Potterton E83491 fault code information on this page is sourced and cross-checked against the official Potterton service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026