Atlantic W12

Atlantic error code W12 indicates: Atlantic Calypso / Explorer / Linéo / Aéromax Thermodynamic Water Heater & DHW Tank: Diagnostic fault code W12 registered by the microcomputer controller. Cozytouch wireless radio communication module link loss.

The primary root cause for Atlantic code W12 is: On Atlantic appliances engineered with ACI Hybride dynamic titanium/magnesium cathodic anti-corrosion protection, Steatite dry ceramic heating element housed in enameled pocket, and thermodynamic heat-pump circuit with 10 kΩ NTC evaporator thermistors: Cozytouch radio communication board power supply failure or radio link lost to gateway Metrological tolerance verification: regulated logic power supply 5.0V DC ± 0.2V on radio module connector..

To resolve error code W12: Disconnect mains power before servicing. Unplug the harness at the main PCB and use a calibrated digital multimeter: check 5V DC supply rail to radio module and re-pair gateway using Cozytouch mobile application. Inspect contacts for pin oxidation or loose terminals. Replace defective part if out of tolerance, re-energize and clear error: On the touch display: press Menu, select 'Installer / Advanced settings', enter code (hold Return and Menu together for 5 seconds). Scroll to 'Fault history', choose 'Clear history' and validate. If ACI lockout occurs, power off mains for 30 seconds and confirm water tank is completely pressurized before power-on.

Resetting power (unplugging for 5–10 minutes) clears temporary memory errors. However, if Atlantic code W12 persists, the physical component causing On Atlantic appliances engineered with ACI Hybride dynamic titanium/magnesium cathodic anti-corrosion protection, Steatite dry ceramic heating element housed in enameled pocket, and thermodynamic heat-pump circuit with 10 kΩ NTC evaporator thermistors: Cozytouch radio communication board power supply failure or radio link lost to gateway Metrological tolerance verification: regulated logic power supply 5.0V DC ± 0.2V on radio module connector. must be inspected or replaced.

Set a digital multimeter to ohms (Ω). Disconnect power and test Compressor Motor Windings (Run/Start) & Defrost Heater across Across 3 compressor pins (Common, Run, Start): R(C-S) + R(C-R) = R(S-R). Winding to earth: >20MΩ (OL).. Expected nominal reading is 15Ω–25Ω (Run C-R), 20Ω–35Ω (Start C-S), 200Ω–400Ω (Defrost Heater). PTC Relay: 10Ω–30Ω at 25°C.. Tolerance: ±10%. Any low insulation resistance to casing (<2MΩ) trips the breaker. Defrost bimetal reads <0.5Ω when sub-zero..

Standard electrical safety protocol: 1. Disconnect 230V mains power before opening panels. 2. Verify zero voltage at test points. 3. Allow hot water or heating elements to cool below 30°C before handling.