Thermia · No longer sold new in the UK. 46 codes across 3 product families, each taken from the manufacturer’s manuals. Thermia technical support ↗
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Type the code on your display or a word from its meaning. Each code opens its own page with what it means, whether it is safe and what you can check.
46 codes
| Code | Meaning | Stops? | Homeowner check? |
|---|---|---|---|
| aux-heater | Overheating protection deployed. No auxiliary heater. | Partly | Yes |
| brine-out | Brine out is less than the set minimum temperature. Compressor stopped. No hot water production. | Yes | Yes |
| brineflow-low | Flow sensor not active during last start. Compressor stopped. No hot water production. | Yes | Yes |
| buffer-tank-sensor | Sensor fault alternatively cable fault. | Partly | Yes |
| com-error-expansion-card | Communication broken between display card and expansion card (indoor). | Partly | Yes |
| com-error-exv-card | Communication broken between display card and expansion valve control card (outdoor). | Yes | Yes |
| com-error-hp-card | Communication broken between display card and heat pump card (outdoor). | Yes | Yes |
| com-error-hub-card | Communication broken between display card and hub card (indoor). | Yes | Yes |
| defrost-sensor | Sensor fault alternatively cable fault. Defrost sensor. | Partly | Yes |
| discharge-pipe-sensor | Sensor fault alternatively cable fault. | Partly | Yes |
| distr-cir-1-sensor | Sensor fault alternatively cable fault. | Partly | Yes |
| distr-cir-2-sensor | Sensor fault alternatively cable fault. | Partly | Yes |
| el-heater-error | The electrical heater overheating protection has deployed. | Partly | Yes |
| err-phase-seq | Alarm that indicates that there is an incorrect phase sequence to the compressor. Only display and only the first 10 minutes. | Not stated | Yes |
| failsafe-mode | Sensor fault alternatively cable fault on one of the refrigerant sensors. The heat pump goes to failsafe mode and defrosts on time. | Partly | Yes |
| heat-pressure-error | The expected pressure and temperature change in the refrigerant circuit has not happened in the correct way at compressor start. | Yes | Yes |
| heating-circ-pump | Circulation pump is jammed. | Yes | Yes |
| heating-system-pump | Circulation pump is jammed. | Partly | Yes |
| hgw-sensor | Sensor fault alternatively cable fault. | Partly | Yes |
| high-pressure-error | High pressure switch has deployed. | Yes | Yes |
| high-return | Alarm that indicates that high return temperature prevents the compressor's operation. | Partly | Yes |
| high-return-line-temp | Return line temperature too high | Partly | Yes |
| hot-water-sensor | Sensor fault alternatively cable fault (the lower sensor, Start sensor). | Partly | Yes |
| hot-water-top | Sensor fault alternatively cable fault. | Partly | Yes |
| low-evap-temp-1 | Evaporation temperature too low. | Yes | Yes |
| low-evap-temp-2 | Too great a deviation in evaporation temperature average value. | Yes | Yes |
| low-heat-cir-flow | The flow sensor has registered too low a flow. | Yes | Yes |
| low-pressure-error | Evaporation pressure has fallen too low. | Yes | Yes |
| low-pressure-transducer | Fault in low pressure transmitter alternatively cable fault. | Yes | Yes |
| low-return-temp-1 | The return line temperature is too low to start a defrosting. | Partly | Yes |
| low-return-temp-2 | The return line has fallen too low during defrosting. | Partly | Yes |
| max-temp-elec-hw | Too high temperature in heat pump junction box/electrical cabinet. | Not stated | Yes |
| motor-p-comp-error | The compressor motor protection has deployed. | Yes | Yes |
| motor-p-error | Deployed overload relay (overcurrent relay compressor), deployed overload relay for outdoor unit fan. On certain models alarms from the brine pump and soft starter can also occur. Compressor stopped. | Yes | Yes |
| motor-p-fan-error | The fan motor protection has deployed. | Yes | Yes |
| no-of-tries-x-5 | Circulation pump is jammed. Start attempt made. | Partly | Yes |
| outdoor-sensor | Sensor fault alternatively cable fault. | Partly | Yes |
| pool-sensor | Sensor fault alternatively cable fault. | No | Yes |
| refr-1-sensor | Sensor fault alternatively cable fault. Refrigerant sensor 1 | Partly | Yes |
| refr-2-sensor | Sensor fault alternatively cable fault. Refrigerant sensor 2 | Partly | Yes |
| return-line-sensor | Sensor fault alternatively cable fault. Return line sensor. | Partly | Yes |
| room-sensor | Sensor fault alternatively cable fault. | No | Yes |
| sensor-cooling | Sensor fault. Cooling function stops. | Partly | Yes |
| suction-temp-sensor | Sensor fault alternatively cable fault. | Partly | Yes |
| supply-line-sensor | Sensor fault alternatively cable fault. Supply line sensor. | Varies by model | Yes |
| system-supply-line-sensor | Sensor fault alternatively cable fault. System supply line sensor. | Partly | Yes |