BoilerFaultCodesPotterton E35 Fault Code
The Potterton E35 fault code means: your boiler is detecting a flame when there shouldn't be one, leading to a safety lockout to prevent incorrect operation.. It appears on 3 Potterton models in our database.
Technical description: Flame circuit / parasitic flame fault
What causes the Potterton E35 fault?
This fault occurs when the boiler's internal sensors detect a flame after the burner should have switched off, or even before it has started. The most common reasons are a dirty or damaged sensing electrode sending a false signal, or a malfunction in the main control board that misinterprets electrical current as a live flame.
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 E35 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Potterton E35 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