T603 Modbus Thermostat

T603 Modbus Thermostat Operation Functions

All setting operations of the T603 Modbus Thermostat are listed below.

1. Clock Adjustment
– Enter: While on, press and hold the Fan Speed button for 5 seconds.
– Adjust: Blue text indicates the active setting. Press Fan Speed to cycle through minutes, hours, and day-of-week. Use Up/Down buttons to change values.
– Save & Exit: Press the Power button.

2. Timer Function
-Enter: While on, press and hold the Mode button for 5 seconds.
Adjust: Blue text indicates the active setting. Press Fan Speed to cycle through timer minutes, hours, and status. Press Mode to switch between timer-on and timer-off settings. Use Up/Down buttons to change values.
– Save & Exit: Press the Power button.


3. Child Lock
-Toggle: While on, press and hold both Up and Down buttons for 5 seconds to enable/disable. When enabled, all buttons except Power are locked.

4. Factory Reset
– Action: While on, press and hold the Power and Down buttons together for 5 seconds.

5. Fault Alarm
-Trigger: Sensor short-circuit or temperature outside -30 ℃ to 80 ℃ range.
-Display: Shows “E1” on the screen and disconnects all loads. Returns to normal after the fault is cleared.


6. Frost Protection
– Condition: Activated when the unit is off.
– Action: Output turns on if room temperature ≤5 ℃ and turns off once it reaches ≥7 ℃, repeating this cycle.


7. Temperature Control Logic
– Cooling / AC + Floor Cooling: Output turns ON when room temp > (set temp + start differential). Turns OFF when room temp ≤ (set temp – 1℃).
– Heating / AC + Floor Heating / Hydronic Heating: Output turns ON when room temp < (set temp – start differential). Turns OFF when room temp ≥ (set temp + 1℃).
– Note: Fresh air and refrigerant-based AC systems are not temperature-controlled.

8. Advanced Mode
– Enter: While off, press and hold the Mode and Fan Speed buttons together for 5 seconds.
– Navigate: Use Up/Down to select a category → Press Mode to enter → Adjust parameters with Up/Down → Press Mode again to return to the category list.
– Save & Exit: From the category list, press the Power button. (Note: You must return to the category list to exit.)

Beyond basic timing and screen lock operations, the T603 Modbus Thermostat is an advanced touch-controlled smart fan coil thermostat designed for indoor temperature control of heat pump systems, dual-source heating & cooling units, 2-pipe and 4-pipe fan coil systems.
Powered by an advanced microcontroller chip, it detects ambient temperature via its built-in high-precision internal sensors, compares the actual temperature with user preset target values, and automatically regulates the working state of fan coils and motorized valves at the end of the air conditioning system.
This intelligent closed-loop adjustment delivers consistent comfortable indoor temperature while effectively reducing overall energy consumption.

With Modbus RTU communication built inside the T603 Modbus Thermostat, all temperature records and operating parameters can be transmitted to the central control panel remotely. Property managers can monitor and adjust the running mode of every thermostat unit in offices, shopping malls and residential villas without on-site manual operation, greatly improving the efficiency of HVAC system management.