Boiler does not ignite, display shows E01, no flame symbol, heating and hot water unavailable.

Safety first: Turn the boiler off with the main power switch and isolate it from the electrical supply. Close the gas cock before removing any covers. If you smell gas, ventilate the room and contact a qualified gas technician immediately.

Basic checks (user level):

• Verify that the gas cock under the Termet boiler is fully open and that other gas appliances in the home work correctly.
• Check system pressure on the manometer (usually 1.0–1.5 bar when cold). If low, top up via the filling loop according to the user manual.
• Reset the boiler using the reset button or control knob and observe if ignition is attempted (clicking sound from the ignition transformer and gas valve).

Technical checks (qualified technician only):

• Remove the front casing and inspect the ignition electrode and ionisation electrode near the burner. Clean light deposits with fine abrasive pad and ensure correct gap and positioning as per Termet service manual.
• Check the wiring harness from the electrodes to the main control PCB for damage, loose connectors, or signs of tracking.
• Measure gas inlet pressure and burner pressure with a manometer; adjust or replace the gas valve assembly if pressures are out of specification.
• Verify flame signal (µA) at the ionisation electrode during operation; if no signal, replace the ionisation electrode or the main PCB as required.

If E01 persists after basic checks, stop using the boiler and arrange service from an authorised Termet technician.