Wiser
Wiser Smart Thermostats Error Codes
Complete list of fault codes and troubleshooting guides. Use the search below to find your specific error.
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E01
Thermostat display shows E01 and cannot connect to the Wiser Heat Hub or app
Wi‑Fi / Zigbee Radio Communication Failure
E02
Thermostat shows E02 and does not control heating correctly
Internal Temperature Sensor Failure
E03
Thermostat displays E03 and heating does not respond to setpoint changes
Relay / Output Driver Fault
E04
Thermostat shows E04 and cannot detect the boiler or heating circuit
Boiler Demand Signal / Call-for-Heat Circuit Fault
E05
Thermostat shows E05 and hot water control is unavailable
Hot Water Channel Output Fault
E06
Thermostat shows E06 and room temperature reading is clearly wrong (e.g. -20°C or 60°C)
Room Temperature Sensor Out of Range
E07
Thermostat shows E07 and cannot control underfloor heating temperature correctly
Remote Floor Sensor Fault (for UFH setups)
E08
Thermostat shows E08 and battery icon flashes or device powers off intermittently
Low Battery / Power Supply Fault
E09
Thermostat shows E09 and cannot join the Wiser system after a reset
Pairing / Commissioning Failure
E10
Thermostat shows E10 and schedules do not run; time and date keep resetting
Real-Time Clock / Memory Fault
E11
Thermostat shows E11 and cannot control a specific smart radiator thermostat (TRV)
Zigbee Device Link Failure (Smart Radiator Thermostat)
E12
Thermostat shows E12 and cannot control a specific heating zone or room
Zone Binding / Mapping Error
E13
Thermostat shows E13 and the app reports a firmware update failure
Firmware Update / Flash Write Error
E14
Thermostat shows E14 and the display is frozen or unresponsive to touch/buttons
User Interface / Touch Panel Fault
E15
Thermostat shows E15 and the boiler cycles rapidly or does not respond correctly
OpenTherm / Digital Boiler Communication Fault (where supported)
E16
Thermostat shows E16 and reports over-temperature or safety shutdown
Over-Temperature Protection Triggered
E17
Thermostat shows E17 and cannot connect to the internet or Wiser cloud services
Cloud / Internet Connectivity Fault
E18
Thermostat shows E18 and reports humidity sensor error (on models with humidity)
Internal Humidity Sensor Failure
E19
Thermostat shows E19 and cannot control cooling (for heat pump / cooling-enabled systems)
Cooling Output / Reversing Valve Control Fault
E20
Thermostat shows E20 and reports sensor calibration error
Sensor Calibration / Offset Error
Symptom
Condensation or visible moisture inside the thermostat cover.
Moisture Ingress / Environmental Damage Risk
Symptom
Heating stays on constantly even when the thermostat is set low or off.
Stuck Relay / Permanent Call-for-Heat.
Symptom
Heating will not turn on even though the thermostat is calling for heat (no error code shown).
No Heat Output / Call-for-Heat Not Reaching Boiler.
Symptom
Hot water does not heat up according to the schedule, but heating works normally.
Hot Water Control / Scheduling Fault
Symptom
Room never reaches the set temperature; heating cuts off early.
Under-Heating / Early Cut-Off.
Symptom
Room temperature overshoots the setpoint by several degrees before heating turns off.
Poor Temperature Control / Overshoot.
Symptom
Smart radiator thermostats (TRVs) do not open or close properly; some rooms stay cold or hot.
Smart Radiator Thermostat Mechanical / Control Fault.
Symptom
The thermostat buttons are stiff or do not click properly (on button-based models).
Mechanical Button Wear / Contamination
Symptom
The thermostat does not respond to voice assistant commands (e.g., Alexa, Google) but works locally.
Third-Party Integration / API Fault
Symptom
The thermostat randomly resets or restarts during normal operation.
Unexpected Reboot / Power Instability
Symptom
The thermostat shows large, sudden jumps in temperature readings (e.g., 20°C to 28°C within minutes) without environmental change.
Erratic Temperature Sensing
Symptom
Thermostat backlight flickers or the display intermittently dims.
Display Power / Backlight Instability.
Symptom
Thermostat display is completely blank and unresponsive.
No Power to Thermostat.
Symptom
Thermostat emits a burning smell or feels unusually hot to the touch.
Overheating Electronics / Potential Short.
Symptom
Thermostat frequently disconnects from the app or shows as offline.
Intermittent Wireless Connectivity.
Symptom
Thermostat makes clicking noises, but the boiler does not start.
Relay Operating, but No Boiler Response.
Symptom
Thermostat time schedule does not follow programmed times; heating turns on/off at wrong times.
Scheduling / Timekeeping Issue
| Error Code | Symptom | Fault Type | Guide |
|---|---|---|---|
| E01 |
Thermostat display shows E01 and cannot connect to the Wiser Heat Hub or app
|
Wi‑Fi / Zigbee Radio Communication Failure | View Details |
| E02 |
Thermostat shows E02 and does not control heating correctly
|
Internal Temperature Sensor Failure | View Details |
| E03 |
Thermostat displays E03 and heating does not respond to setpoint changes
|
Relay / Output Driver Fault | View Details |
| E04 |
Thermostat shows E04 and cannot detect the boiler or heating circuit
|
Boiler Demand Signal / Call-for-Heat Circuit Fault | View Details |
| E05 |
Thermostat shows E05 and hot water control is unavailable
|
Hot Water Channel Output Fault | View Details |
| E06 |
Thermostat shows E06 and room temperature reading is clearly wrong (e.g. -20°C or 60°C)
|
Room Temperature Sensor Out of Range | View Details |
| E07 |
Thermostat shows E07 and cannot control underfloor heating temperature correctly
|
Remote Floor Sensor Fault (for UFH setups) | View Details |
| E08 |
Thermostat shows E08 and battery icon flashes or device powers off intermittently
|
Low Battery / Power Supply Fault | View Details |
| E09 |
Thermostat shows E09 and cannot join the Wiser system after a reset
|
Pairing / Commissioning Failure | View Details |
| E10 |
Thermostat shows E10 and schedules do not run; time and date keep resetting
|
Real-Time Clock / Memory Fault | View Details |
| E11 |
Thermostat shows E11 and cannot control a specific smart radiator thermostat (TRV)
|
Zigbee Device Link Failure (Smart Radiator Thermostat) | View Details |
| E12 |
Thermostat shows E12 and cannot control a specific heating zone or room
|
Zone Binding / Mapping Error | View Details |
| E13 |
Thermostat shows E13 and the app reports a firmware update failure
|
Firmware Update / Flash Write Error | View Details |
| E14 |
Thermostat shows E14 and the display is frozen or unresponsive to touch/buttons
|
User Interface / Touch Panel Fault | View Details |
| E15 |
Thermostat shows E15 and the boiler cycles rapidly or does not respond correctly
|
OpenTherm / Digital Boiler Communication Fault (where supported) | View Details |
| E16 |
Thermostat shows E16 and reports over-temperature or safety shutdown
|
Over-Temperature Protection Triggered | View Details |
| E17 |
Thermostat shows E17 and cannot connect to the internet or Wiser cloud services
|
Cloud / Internet Connectivity Fault | View Details |
| E18 |
Thermostat shows E18 and reports humidity sensor error (on models with humidity)
|
Internal Humidity Sensor Failure | View Details |
| E19 |
Thermostat shows E19 and cannot control cooling (for heat pump / cooling-enabled systems)
|
Cooling Output / Reversing Valve Control Fault | View Details |
| E20 |
Thermostat shows E20 and reports sensor calibration error
|
Sensor Calibration / Offset Error | View Details |
| – |
Condensation or visible moisture inside the thermostat cover.
|
Moisture Ingress / Environmental Damage Risk | View Details |
| – |
Heating stays on constantly even when the thermostat is set low or off.
|
Stuck Relay / Permanent Call-for-Heat. | View Details |
| – |
Heating will not turn on even though the thermostat is calling for heat (no error code shown).
|
No Heat Output / Call-for-Heat Not Reaching Boiler. | View Details |
| – |
Hot water does not heat up according to the schedule, but heating works normally.
|
Hot Water Control / Scheduling Fault | View Details |
| – |
Room never reaches the set temperature; heating cuts off early.
|
Under-Heating / Early Cut-Off. | View Details |
| – |
Room temperature overshoots the setpoint by several degrees before heating turns off.
|
Poor Temperature Control / Overshoot. | View Details |
| – |
Smart radiator thermostats (TRVs) do not open or close properly; some rooms stay cold or hot.
|
Smart Radiator Thermostat Mechanical / Control Fault. | View Details |
| – |
The thermostat buttons are stiff or do not click properly (on button-based models).
|
Mechanical Button Wear / Contamination | View Details |
| – |
The thermostat does not respond to voice assistant commands (e.g., Alexa, Google) but works locally.
|
Third-Party Integration / API Fault | View Details |
| – |
The thermostat randomly resets or restarts during normal operation.
|
Unexpected Reboot / Power Instability | View Details |
| – |
The thermostat shows large, sudden jumps in temperature readings (e.g., 20°C to 28°C within minutes) without environmental change.
|
Erratic Temperature Sensing | View Details |
| – |
Thermostat backlight flickers or the display intermittently dims.
|
Display Power / Backlight Instability. | View Details |
| – |
Thermostat display is completely blank and unresponsive.
|
No Power to Thermostat. | View Details |
| – |
Thermostat emits a burning smell or feels unusually hot to the touch.
|
Overheating Electronics / Potential Short. | View Details |
| – |
Thermostat frequently disconnects from the app or shows as offline.
|
Intermittent Wireless Connectivity. | View Details |
| – |
Thermostat makes clicking noises, but the boiler does not start.
|
Relay Operating, but No Boiler Response. | View Details |
| – |
Thermostat time schedule does not follow programmed times; heating turns on/off at wrong times.
|
Scheduling / Timekeeping Issue | View Details |
No matching codes found
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