Thermostat shows E02 and does not detect the boiler; remote control of heating and DHW is disabled

Safety: Switch off boiler power before opening its front panel. Only access user-level menus unless you are qualified.

• Step 1 – Check boiler status: Confirm the Immergas boiler is powered on and not in lockout. Reset the boiler if a lockout is active.
• Step 2 – Verify BUS activation: On the boiler control panel, enter the installer or advanced menu (refer to the boiler manual) and confirm that the external thermostat/BUS control is enabled.
• Step 3 – Confirm thermostat type: Some Immergas boilers require selecting the correct thermostat model (e.g., CARV2, SMARTECH, or specific smart thermostat) in the boiler configuration. Adjust if incorrect.
• Step 4 – Re-register device: If your thermostat is a wireless Immergas smart thermostat with a gateway, re-pair it following the manufacturer’s pairing procedure.
• Step 5 – Factory reset thermostat: Perform a factory reset on the thermostat (see user manual). Reconfigure language, Wi‑Fi, and boiler connection.
• Step 6 – Service call: If E02 persists, the thermostat main board or boiler control board may be defective. Contact an authorized Immergas technician.