Meross
Meross 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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E1
Thermostat displays E1 and cannot control heating; app shows sensor error or room temperature reads “--” or an impossible value.
Internal Room Temperature Sensor Failure
E10
Thermostat shows E10 and heating cycles are blocked; app may show overcurrent or load error.
Overcurrent Protection on Heating Output
E11
Thermostat displays E11 and cannot join the Meross cloud; local control may still work.
Cloud Communication or TLS Handshake Error
E12
Thermostat shows E12 and schedules or settings are lost after power interruptions.
Non-Volatile Memory (NVM) Write Error
E13
Thermostat displays E13 and time or schedule functions behave erratically; clock may reset unexpectedly.
Real-Time Clock (RTC) or Backup Power Fault
E14
Thermostat shows E14 and cannot complete startup; display may freeze on logo.
Firmware Bootloader or System Crash
E15
Thermostat displays E15 and cannot detect paired remote sensors or radiator valves (for systems using Meross TRVs or remote sensors).
Accessory Communication Failure (Sub-GHz or BLE)
E2
Thermostat shows E2 and heating does not start or stops unexpectedly; app may show floor sensor error on underfloor heating models.
External Floor Temperature Sensor Open/Short
E3
Thermostat displays E3 and heating output is disabled; device may feel unusually warm to the touch.
Internal Overheat Protection Triggered
E4
Thermostat shows E4 and cannot control heating; app may indicate power supply or hardware fault.
Low Voltage or Power Supply Fault
E5
Thermostat displays E5 and heating output is locked out; may occur after a short circuit or wiring change.
Output Relay or Triac Short-Circuit Protection
E6
Thermostat shows E6 and does not respond to temperature changes; app may show calibration or sensor range error.
Temperature Sensor Calibration Out of Range
E7
Thermostat displays E7 and cannot connect to heating system; app may show valve/boiler control error.
Control Output Feedback Error
E8
Thermostat shows E8 and Wi‑Fi icon may flash; app cannot control the thermostat reliably.
Wi‑Fi Module Hardware Fault
E9
Thermostat displays E9 and buttons or touch interface do not respond correctly; app may still control the device.
User Interface Panel Communication Error
Symptom
Heating runs continuously and does not turn off even when the set temperature is reached or the thermostat is turned off.
Stuck Heating Relay / Output Permanently On
Symptom
Thermostat buttons or touch controls are unresponsive or register random presses.
User Interface Malfunction
Symptom
Thermostat cannot be discovered or added in the Meross app during setup.
Pairing / Provisioning Failure
Symptom
Thermostat cannot control paired Meross smart radiator valves (TRVs); valves do not open or close as expected.
TRV Coordination / Binding Fault
Symptom
Thermostat causes the boiler to fire even when no heating demand is expected (e.g., in OFF mode).
False Heat Demand / Ghost Firing
Symptom
Thermostat display fogs up or shows condensation inside the screen, especially in bathrooms or humid areas.
Moisture Ingress / Condensation
Symptom
Thermostat display is very dim, flickers, or backlight pulses when the relay switches.
Display Power Instability
Symptom
Thermostat does not follow programmed schedules; heating turns on or off at unexpected times.
Schedule Misbehavior / Logic Error
Symptom
Thermostat does not power on at all; display is blank and app cannot find the device.
No Power to Thermostat
Symptom
Thermostat emits a burning smell or visible smoke during operation.
Severe Overheating / Component Burnout
Symptom
Thermostat emits a buzzing or clicking noise from inside the unit when switching the heating on or off.
Noisy Relay Operation / Electrical Buzz
Symptom
Thermostat frequently disconnects from Wi‑Fi; app shows device offline intermittently.
Intermittent Wi‑Fi Connectivity
Symptom
Thermostat frequently overshoots the set temperature, making the room too warm before turning off.
Temperature Overshoot / Poor Control Calibration
Symptom
Thermostat loses its Wi‑Fi configuration or pairing after a power outage and must be set up again.
Configuration Loss / Volatile Network Settings
Symptom
Thermostat or surrounding wall feels unusually warm to the touch during normal operation.
Excessive Internal Heating
Symptom
Thermostat powers on but does not call for heat even when room temperature is well below the setpoint.
No Heat Call / Control Output Not Activating
Symptom
Thermostat rapidly cycles the heating on and off in short bursts, causing wear on the boiler or relay.
Short Cycling / Incorrect Control Parameters
Symptom
Thermostat shows a constant temperature reading that does not change over time, even when the room clearly warms or cools.
Stuck Temperature Reading / Sensor Freeze
Symptom
Thermostat shows incorrect time or time zone, causing schedules to run at the wrong times.
Time Synchronization / Time Zone Misconfiguration
Symptom
Thermostat underheats; room never reaches the set temperature even though heating runs for long periods.
Insufficient Heat Output / Sensor Misreading
| Error Code | Symptom | Fault Type | Guide |
|---|---|---|---|
| E1 |
Thermostat displays E1 and cannot control heating; app shows sensor error or room temperature reads “--” or an impossible value.
|
Internal Room Temperature Sensor Failure | View Details |
| E10 |
Thermostat shows E10 and heating cycles are blocked; app may show overcurrent or load error.
|
Overcurrent Protection on Heating Output | View Details |
| E11 |
Thermostat displays E11 and cannot join the Meross cloud; local control may still work.
|
Cloud Communication or TLS Handshake Error | View Details |
| E12 |
Thermostat shows E12 and schedules or settings are lost after power interruptions.
|
Non-Volatile Memory (NVM) Write Error | View Details |
| E13 |
Thermostat displays E13 and time or schedule functions behave erratically; clock may reset unexpectedly.
|
Real-Time Clock (RTC) or Backup Power Fault | View Details |
| E14 |
Thermostat shows E14 and cannot complete startup; display may freeze on logo.
|
Firmware Bootloader or System Crash | View Details |
| E15 |
Thermostat displays E15 and cannot detect paired remote sensors or radiator valves (for systems using Meross TRVs or remote sensors).
|
Accessory Communication Failure (Sub-GHz or BLE) | View Details |
| E2 |
Thermostat shows E2 and heating does not start or stops unexpectedly; app may show floor sensor error on underfloor heating models.
|
External Floor Temperature Sensor Open/Short | View Details |
| E3 |
Thermostat displays E3 and heating output is disabled; device may feel unusually warm to the touch.
|
Internal Overheat Protection Triggered | View Details |
| E4 |
Thermostat shows E4 and cannot control heating; app may indicate power supply or hardware fault.
|
Low Voltage or Power Supply Fault | View Details |
| E5 |
Thermostat displays E5 and heating output is locked out; may occur after a short circuit or wiring change.
|
Output Relay or Triac Short-Circuit Protection | View Details |
| E6 |
Thermostat shows E6 and does not respond to temperature changes; app may show calibration or sensor range error.
|
Temperature Sensor Calibration Out of Range | View Details |
| E7 |
Thermostat displays E7 and cannot connect to heating system; app may show valve/boiler control error.
|
Control Output Feedback Error | View Details |
| E8 |
Thermostat shows E8 and Wi‑Fi icon may flash; app cannot control the thermostat reliably.
|
Wi‑Fi Module Hardware Fault | View Details |
| E9 |
Thermostat displays E9 and buttons or touch interface do not respond correctly; app may still control the device.
|
User Interface Panel Communication Error | View Details |
| – |
Heating runs continuously and does not turn off even when the set temperature is reached or the thermostat is turned off.
|
Stuck Heating Relay / Output Permanently On | View Details |
| – |
Thermostat buttons or touch controls are unresponsive or register random presses.
|
User Interface Malfunction | View Details |
| – |
Thermostat cannot be discovered or added in the Meross app during setup.
|
Pairing / Provisioning Failure | View Details |
| – |
Thermostat cannot control paired Meross smart radiator valves (TRVs); valves do not open or close as expected.
|
TRV Coordination / Binding Fault | View Details |
| – |
Thermostat causes the boiler to fire even when no heating demand is expected (e.g., in OFF mode).
|
False Heat Demand / Ghost Firing | View Details |
| – |
Thermostat display fogs up or shows condensation inside the screen, especially in bathrooms or humid areas.
|
Moisture Ingress / Condensation | View Details |
| – |
Thermostat display is very dim, flickers, or backlight pulses when the relay switches.
|
Display Power Instability | View Details |
| – |
Thermostat does not follow programmed schedules; heating turns on or off at unexpected times.
|
Schedule Misbehavior / Logic Error | View Details |
| – |
Thermostat does not power on at all; display is blank and app cannot find the device.
|
No Power to Thermostat | View Details |
| – |
Thermostat emits a burning smell or visible smoke during operation.
|
Severe Overheating / Component Burnout | View Details |
| – |
Thermostat emits a buzzing or clicking noise from inside the unit when switching the heating on or off.
|
Noisy Relay Operation / Electrical Buzz | View Details |
| – |
Thermostat frequently disconnects from Wi‑Fi; app shows device offline intermittently.
|
Intermittent Wi‑Fi Connectivity | View Details |
| – |
Thermostat frequently overshoots the set temperature, making the room too warm before turning off.
|
Temperature Overshoot / Poor Control Calibration | View Details |
| – |
Thermostat loses its Wi‑Fi configuration or pairing after a power outage and must be set up again.
|
Configuration Loss / Volatile Network Settings | View Details |
| – |
Thermostat or surrounding wall feels unusually warm to the touch during normal operation.
|
Excessive Internal Heating | View Details |
| – |
Thermostat powers on but does not call for heat even when room temperature is well below the setpoint.
|
No Heat Call / Control Output Not Activating | View Details |
| – |
Thermostat rapidly cycles the heating on and off in short bursts, causing wear on the boiler or relay.
|
Short Cycling / Incorrect Control Parameters | View Details |
| – |
Thermostat shows a constant temperature reading that does not change over time, even when the room clearly warms or cools.
|
Stuck Temperature Reading / Sensor Freeze | View Details |
| – |
Thermostat shows incorrect time or time zone, causing schedules to run at the wrong times.
|
Time Synchronization / Time Zone Misconfiguration | View Details |
| – |
Thermostat underheats; room never reaches the set temperature even though heating runs for long periods.
|
Insufficient Heat Output / Sensor Misreading | View Details |
No matching codes found
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