Field Actions
DISPATCHAlways disconnect appliance from 230V/400V mains before opening panels. Use CAT III multimeter for circuit testing.
Frequently Asked Questions: Atlantic W20
FAQ TREEWhat does error code W20 mean on a Atlantic appliance?
Atlantic error code W20 indicates: Atlantic Alféa Excellia / Extensa A.I. / Alféa Hybrid Duo Inverter Heat Pump: Diagnostic fault code W20 registered by the microcomputer controller. Heating hydronic buffer tank NTC temperature sensor circuit fault.
What is the root cause of Atlantic error code W20?
The primary root cause for Atlantic code W20 is: On Atlantic appliances engineered with co-developed Fujitsu twin-rotary DC inverter outdoor stage, Siemens Navistem / RVS hydraulic regulator, electronic expansion valve with 46 Ω stepper phases, and 10 kΩ NTC flow/return temperature sensors: auxiliary heating buffer tank temperature sensor NTC open or short-circuit Metrological tolerance verification: NTC thermistor 10 kΩ at 25°C, 32.5 kΩ at 0°C..
How do I fix or resolve Atlantic error code W20?
To resolve error code W20: Disconnect mains power before servicing. Unplug the harness at the main PCB and use a calibrated digital multimeter: test probe resistance at buffer tank thermowell and check wiring continuity to hydrobox. Inspect contacts for pin oxidation or loose terminals. Replace defective part if out of tolerance, re-energize and clear error: On the Navistem user controller: press OK and hold the 'i' button for 3 seconds to access Specialist mode. Go to line 6700-6800 (Diagnostics), select 'Reset fault log' and set to 'Yes', then press OK. For hard lockout, switch off the 230V/400V mains breaker for 60 seconds to discharge the DC link.
Is it safe to clear Atlantic error code W20 by resetting power?
Resetting power (unplugging for 5–10 minutes) clears temporary memory errors. However, if Atlantic code W20 persists, the physical component causing On Atlantic appliances engineered with co-developed Fujitsu twin-rotary DC inverter outdoor stage, Siemens Navistem / RVS hydraulic regulator, electronic expansion valve with 46 Ω stepper phases, and 10 kΩ NTC flow/return temperature sensors: auxiliary heating buffer tank temperature sensor NTC open or short-circuit Metrological tolerance verification: NTC thermistor 10 kΩ at 25°C, 32.5 kΩ at 0°C. must be inspected or replaced.
How do I test electrical resistance for Atlantic code W20 using a multimeter?
Set a digital multimeter to ohms (Ω). Disconnect power and test NTC Temperature Sensor Probe (Thermistor) across Across sensor pins 1-2 (unplugged harness). Expected nominal reading is 4.8kΩ–12kΩ (at 20°C–25°C). Tolerance: Negative temperature coefficient: resistance drops smoothly when warmed with fingers. OL = open circuit..
What safety protocol must be followed before servicing Atlantic code W20?
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.
Community Verification
COMMUNITYDid this solution resolve the issue?