Field Actions
DISPATCHAlways disconnect appliance from 230V/400V mains before opening panels. Use CAT III multimeter for circuit testing.
Frequently Asked Questions: Atlantic W25
FAQ TREEWhat does error code W25 mean on a Atlantic appliance?
Atlantic error code W25 indicates: Atlantic Alféa Excellia / Extensa A.I. / Alféa Hybrid Duo Inverter Heat Pump: Diagnostic fault code W25 registered by the microcomputer controller. Swimming pool secondary heat exchanger NTC temperature sensor fault.
What is the root cause of Atlantic error code W25?
The primary root cause for Atlantic code W25 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: swimming pool titanium heat exchanger secondary water temperature sensor circuit fault Metrological tolerance verification: NTC thermistor 10 kΩ at 25°C, 14.4 kΩ at 30°C..
How do I fix or resolve Atlantic error code W25?
To resolve error code W25: Disconnect mains power before servicing. Unplug the harness at the main PCB and use a calibrated digital multimeter: measure resistance across pool sensor connector pins on expansion module. 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 W25 by resetting power?
Resetting power (unplugging for 5–10 minutes) clears temporary memory errors. However, if Atlantic code W25 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: swimming pool titanium heat exchanger secondary water temperature sensor circuit fault Metrological tolerance verification: NTC thermistor 10 kΩ at 25°C, 14.4 kΩ at 30°C. must be inspected or replaced.
How do I test electrical resistance for Atlantic code W25 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 W25?
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.
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