Riello · A niche brand in the UK. 125 codes across 2 product families, each taken from the manufacturer’s manuals.
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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.
125 codes
| Code | Meaning | Stops? | Homeowner check? |
|---|---|---|---|
| 1 | EWT sensor failure | No | Yes |
| 2 | LWT sensor failure | Yes | Yes |
| 3 | Refrigerant temperature (TR) sensor failure | Yes | Yes |
| 4 | OAT sensor failure | No | Yes |
| 5 | DHW tank temperature (DHW_TT) sensor failure | Partly | Yes |
| 6 | CHWSTEMP sensor failure | Not stated | Yes |
| 10 | Discharge temperature (TD) sensor failure | Yes | Yes |
| 11 | Air exchanger temperature (TE) sensor failure | Yes | Yes |
| 14 | Suction temperature (TS) sensor failure | Yes | Yes |
| 16 | TE and TS sensors wrongly connected or PMV failure | Yes | Yes |
| 17 | Suction pressure transducer failure | Yes | Yes |
| 20 | Loss of communication with user interface | No | Yes |
| 21 | Loss of communication with inverter | Yes | Yes |
| 23 | Loss of communication with slaves | Partly | Yes |
| 24 | Loss of communication with master | Yes | Yes |
| 25 | Loss of communication with Jbus master | Yes | Yes |
| 31 | Safety input | Yes | Yes |
| 32 | Flow switch failure | Yes | Yes |
| 33 | High pressure switch failure | Yes | Yes |
| 40 | Leak detection alarm | Not stated | Yes |
| 41 | Low superheat failure | Yes | Yes |
| 42 | Compressor not started | Yes | Yes |
| 43 | Drive unconfigured | Yes | Yes |
| 44 | Four-way valve failure | Yes | Yes |
| 45 | Lower fan not started | Yes | Yes |
| 46 | Upper fan not started | Yes | Yes |
| 47 | Machine overcurrent | Yes | Yes |
| 48 | Compressor envelope protection - low TE in cooling | Yes | Yes |
| 49 | Compressor envelope protection - high TE in cooling | Yes | Yes |
| 50 | Exchanger freeze protection on water temperature (in cooling) | Partly | Yes |
| 51 | Exchanger freeze protection on refrigerant temperature (in cooling) | Partly | Yes |
| 52 | Compressor envelope protection - high SST in cooling | Yes | Yes |
| 54 | Compressor envelope protection - high TD | Yes | Yes |
| 55 | Exchanger high temperature protection - high LWT/TR in heating (LWT above 75 C or TR above 70 C) | Yes | Yes |
| 56 | Compressor envelope protection - low LWT/TR in heating | Yes | Yes |
| 57 | Compressor envelope protection - high SST in heating | Yes | Yes |
| 58 | Compressor envelope protection - low SST in heating | Yes | Yes |
| 59 | Compressor envelope protection - high inverter current | Yes | Yes |
| 75 | Inverter fault - DC over voltage | Yes | Yes |
| 76 | Inverter fault - heatsink over temperature | Yes | Yes |
| 77 | Inverter fault - AC under voltage | Yes | Yes |
| 78 | Inverter fault - PFC over current | Yes | Yes |
| 79 | Inverter fault - AC over voltage | Yes | Yes |
| 80 | Inverter fault - PFC unbalanced current | Yes | Yes |
| 81 | Inverter fault - stator over heat | Yes | Yes |
| 82 | Inverter fault - printed board over temperature | Yes | Yes |
| 83 | Inverter fault - IPM temperature sensor error | Yes | Yes |
| 84 | Inverter fault - input wire miss (three-phase) | Yes | Yes |
| 88 | Inverter fault - other inverter alarm | Yes | Yes |
| 89 | Real time clock corrupted | No | Yes |
| 90 | Invalid configuration | Yes | Yes |
| 91 | Invalid configuration - wrong unit type | Yes | Yes |
| 93 | Invalid configuration - wrong supply type | Yes | Yes |
| 95 | Invalid configuration - wrong inverter model | Yes | Yes |
| 96 | Invalid configuration - wrong hydronic configuration | Yes | Yes |
| 97 | Invalid configuration - compressor map failure | Yes | Yes |
| 98 | Invalid configuration - configuration not allowed for master/slave | Yes | Yes |
| 99 | Invalid configuration - master/slave wrong addressing | Yes | Yes |
| 100 | Emergency stop | Yes | Yes |
| 101 | External alarm | No | Yes |
| 200 | Inverter minor fault - compressor current limit | No | Yes |
| 201 | Inverter minor fault - ID current limit | No | Yes |
| 202 | Inverter minor fault - PFCM temperature sensor error | No | Yes |
| 203 | Inverter minor fault - IPM temperature sensor error | No | Yes |
| 204 | Inverter minor fault - input current limit | No | Yes |
| 205 | Inverter minor fault - PFC over current | No | Yes |
| 206 | Inverter minor fault - AC over voltage | No | Yes |
| 210 | TD inconsistent value | No | Yes |
| 213 | TR inconsistent value | No | Yes |
| 214 | TS inconsistent value | No | Yes |
| 232 | Flow switch alert | No | Yes |
| 240 | Leak detection alert | No | Yes |
| 245 | Lower fan running at wrong speed | No | Yes |
| 246 | Upper fan running at wrong speed | No | Yes |
| bH | PED PCB failure | Not stated | Yes |
| C7 | Transducer module temperature too high protection | Not stated | Yes |
| E0 | Water flow fault (after 3 times E8) | Not stated | Yes |
| E1 | Phase loss or neutral wire and live wire are connected reversely (only for three phase unit) | Not stated | Yes |
| E2 | Communication fault between controller and hydraulic module | Not stated | Yes |
| E3 | Final outlet water temp. sensor (T1) fault | Not stated | Yes |
| E4 | Water tank temp. sensor (T5) fault | Not stated | Yes |
| E5 | The condenser outlet refrigerant temperature sensor (T3) error | Not stated | Yes |
| E6 | The ambient temperature sensor (T4) error | Not stated | Yes |
| E7 | Buffer tank up temp. sensor (Tbt1) fault | Not stated | Yes |
| E8 | Water flow failure | Not stated | Yes |
| E9 | Suction temperature sensor (Th) error | Not stated | Yes |
| EA | Discharge temperature sensor (Tp) error | Not stated | Yes |
| Eb | Solar temp. sensor (Tsolar) fault | Not stated | Yes |
| EC | Buffer tank low temp. sensor (Tbt2) fault | Not stated | Yes |
| Ed | Inlet water temp. sensor (Tw_in) malfunction | Not stated | Yes |
| EE | Hydraulic module EEprom failure | Not stated | Yes |
| F1 | Low DC generatrix voltage protection | Not stated | Yes |
| H0 | Communication fault between main board PCB B and main control board of hydraulic module | Not stated | Yes |
| H1 | Communication error between inverter module PCB A and main control board PCB B | Not stated | Yes |
| H2 | Refrigerant liquid temp. sensor (T2) fault | Not stated | Yes |
| H3 | Refrigerant gas temp. sensor (T2B) fault | Not stated | Yes |
| H4 | Three times P6 (L0/L1) protect | Not stated | Yes |
| H5 | Room temp. sensor (Ta) fault | Not stated | Yes |
| H6 | The DC fan failure | Not stated | Yes |
| H7 | Voltage protection | Not stated | Yes |
| H8 | Pressure sensor failure | Not stated | Yes |
| H9 | Outlet water for zone 2 temp. sensor (Tw2) fault | Not stated | Yes |
| HA | Outlet water temp. sensor (Tw_out) fault | Not stated | Yes |
| Hb | Three times PP protection and Tw_out < 7 C | Not stated | Yes |
| Hd | Communication fault between hydraulic modules in parallel | Not stated | Yes |
| HE | Communication error between main board and thermostat transfer board | Not stated | Yes |
| HF | Inverter module board EEprom error [printed description reads 'Suction temperature sensor(Th) error' - apparent misprint] | Not stated | Yes |
| HH | H6 displayed 10 times in 2 hours | Not stated | Yes |
| HP | Low pressure protection in cooling (Pe<0.6 occurred 3 times in an hour) | Not stated | Yes |
| L0 | Module protection | Not stated | Yes |
| L1 | DC generatrix low voltage protection | Not stated | Yes |
| L2 | DC generatrix high voltage protection | Not stated | Yes |
| L4 | MCE malfunction | Not stated | Yes |
| L5 | Zero speed protection | Not stated | Yes |
| L8 | Speed difference >15 Hz protection between the front and the back clock | Not stated | Yes |
| L9 | Speed difference >15 Hz protection between the real and the setting speed | Not stated | Yes |
| P0 | Low pressure switch protection | Not stated | Yes |
| P1 | High pressure switch protection | Not stated | Yes |
| P3 | Compressor overcurrent protection | Not stated | Yes |
| P4 | High discharge temperature protection | Not stated | Yes |
| P5 | Inlet water temp. sensor (Tw_in) malfunction [as printed; corrective actions relate to water flow / temperature difference] | Not stated | Yes |
| P6 | Module protection (shown with L0) | Not stated | Yes |
| Pb | Anti-freeze mode | Not stated | Yes |
| Pd | High temperature protection of refrigerant outlet temp of condenser | Not stated | Yes |
| PP | Tw_out - Tw_in unusual protection | Not stated | Yes |