XH-W1321 Microcomputer digital thermostat temperature controller

XH-W1321 is a mini embedded digital thermostat (temperature controller) with a compact ABS casing, designed for precise 0.1°C temperature monitoring and control in small-to-medium systems.

Specifications

Parameter	Details
Model	XH-W1321
Shell Material	ABS (black casing)
Dimensions	56 × 38 × 32 mm (2.17 × 1.50 × 1.26″)
Mounting Hole	46 × 34 mm
Power Input	DC 12V (optional 24V/220V)
Temperature Range	-50°C to 110°C
Accuracy	0.1°C (display & control)
Sensor	NTC 10K waterproof probe (1m cable)
Output	10A relay (heating/cooling switch)
Display	Red LED (blue optional)

Key Features

• Precision Control: 0.1°C accuracy for tight temperature regulation.
• Compact Embedded Design: Fits into small enclosures (56×38mm) for seamless installation.
• Waterproof Sensor: 1m NTC probe works in humid/wet environments.
• Dual Mode: Supports both heating and cooling control via relay output.
• Digital LED Display: Clear real-time temperature readout with °C indicator.
• Simple Operation: 3-button interface (SET/UP/DOWN) for easy parameter adjustment.
• High Load Capacity: 10A relay handles most small heating/cooling devices.

Applications

1. Refrigeration/Freezers: Control temperature in mini-fridges, freezers, or cold storage.
2. Aquariums & Terrariums: Maintain stable water/ambient temps for fish/reptiles.
3. DIY Heating Projects: Manage temperature in incubators, fermentation chambers, or greenhouses.
4. HVAC & Ventilation: Regulate small heaters, fans, or exhaust systems.
5. Industrial Equipment: Monitor/control temps in cabinets, enclosures, or lab devices.

How to set?

In normal using,press once, directly enter into the stop temperature setting state, use the up
and down keys to set the required stop temperature, long-time press to enter the internal
settings menu;
Long-time press the SET button to enter the internal settings, use the up button to increase
the value set;
Long-time press the SET button to enter the internal settings, use the down button to reduce
the value setting;

Set hysteresis
Why do you want to set the hysteresis setting? When the control device, the temperature will
rise or fall, how many degrees of temperature change equipment to work again? If you want the
temperature changes 10 ℃, the device work again, you need to set the back value of 10, by
setting Hysteresis, the device can be in the temperature range of reciprocating work.

Set the stop temperature
Normal display state press the set button once to stop the temperature Digital flash, you can
set the required stop temperature value by using the up and down keys;
How do I restore factory settings?
Power on the situation, while holding down the up and down keys, digital display 888, then
automatically jump to the detection temperature, that is, to restore the factory settings;

P0: working mode
This value must be set for the first time to use the thermostat. If it is used for heating, it
should be set to H; if it is used for cooling, it is necessary to set to C.
P1: hysteresis setting
Long-time press the set button for 3 seconds ,enter into the internal menu, select P1, then
press the set button, enter the hysteresis value set state. Hysteresis is the value that,when
the thermostat reaches the set temperature, then stop working, the need to work again the
difference, such as set to the heating mode, heating to 40 ℃ stop, down to 35 ℃ again, the
hysteresis is 5;

P2: temperature correction
Press and hold the key for 3 seconds to enter the internal menu, press the up and down keys to
select P2, then press the set button, through the up and down keys to set the required
calibration temperature. In the setting, if the detected temperature value is 0.5℃ higher
than the actual temperature value, the calibration temperature to be set is -0.5℃. If the
detection temperature is 1℃ lower than the actual temperature, the calibration temperature to
be set is 1℃. Detection temperature +/- correction temperature = actual temperature.

P3: delay start
Press and hold the key to set the desired delay time (minutes). Press the up and down keys to
set the desired delay time (minutes). Delay start is generally used for compressor cooling, if
used for refrigerator freezer, this value needs to be set, according to the compressor back
pressure size is generally set to 3-6 minutes, if you are not used to control the compressor
or do not need to delay Function, skip this item directly.

Error code:
LLL: The sensor is disconnected or damaged;
HHH: The sensor is snapped or out of the measuring range
Screen flash: in the set state or prompt for high and low temperature
alarm
Indicator flashes: in the delay state, need to wait for the end of the
delay to start;

Heating settings:
Set the essentials:
The first step set PO = H, the second step to set the stop temperature, the third step set the
hysteresis value;
Set the way:
1. Press and hold the key to enter the internal menu and set PO to H
2. Press the Setup button to stop the temperature flashing, the up and down keys to set the
temperature;
3. Press and hold the key to enter the internal menu, set the P1 hysteresis setting;
Use case:
Control the water heater. Heating to 65 ℃ stop, the temperature dropped to 50 ℃ again
start heating, how to set up?
Step 1: Determine the operating mode as heating mode, set P0 to H;
Step 2: Press the set button to stop the temperature flashing, through the up and down keys to
set the starting temperature of 50 ℃;
Step 3: stop at 65℃, start again at 50℃, so the hysteresis needs to be set to 65-50 = 15,
enter the internal menu to set P1 to 15, complete;

Cooling mode setting method.
Set the first step to set P0 = C, the second step to set the stop temperature, the third step
to set the hysteresis value;
Set the way:
1. Press and hold the key to enter the internal menu, set the PO to C;
2. Press the Setup button to stop the temperature flashing, the up and down keys to set the
temperature;
3. Press and hold the key to enter the internal menu, set the P1 hysteresis setting;

Use case:
Control the farm, ventilation to 26 ℃ to stop, the temperature rose to 28 ℃ to start the
cooling again, how to set up?
Step 1: Determine the operating mode for the cooling mode, set P0 to C;
The second step: press the set button to stop the temperature flashing, through the up and
down keys to set the stop temperature of 28 ℃;
The third step: 26 ℃ stop, 28 ℃ start again, so the hysteresis need to be set to 28-26 = 2,
enter the internal menu will be set to 2, 2, finish cooling case set.

  

Prompt:

Set the time, if you accidentally set the working mode and set their own stop temperature is

not the corresponding, the indicator light will not light, the load does not work.If the above situation, you can view the P0, P1, P3.

FAQ