BoilerFaultCodesWhat the manual says
Manufacturer manualFault - supply voltage. Burner blocked
What causes this fault?
This fault occurs when the boiler's internal control system detects an issue with the electrical power reaching the burner components. The most common reason is a failure in the ignition transformer or the main control board, which prevents the boiler from creating a spark to light the gas. It can also be triggered by loose internal wiring or fluctuations in your home's mains electricity supply.
Engineer required
This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Avoid the next call-out bill
A cover plan would handle faults like E4: no call-out fees, no surprise bills.
Affiliate links. We may earn a commission at no extra cost to you.
Related fault codes
All 75 fault codes on the Vitodens 333-F
Seeing a different code? Every code this model can display, in one place.