Elitech STC-1000, STC-1000HX and STC-1000X

Single-probe thermostat with one cooling relay and one heating relay that switches between the two automatically around one set point.

What it is: Heat/cool thermostat. The original STC-1000, the STC-1000HX-02 and the STC-1000X share the same four-key layout and F-codes. Ranges differ slightly between the original and the newer HX/X; both are given where they differ (HX and X are identical).

Key combo: Hold S (STC-1000) or the set key (STC-1000HX) for 3 s to open the F-menu.

Error codes ↓
Enter service mode ↓
Parameters ↓
Change a setting ↓

Elitech STC-1000, STC-1000HX and STC-1000X error codes

Code	Meaning	Likely cause	How to reset
EE	Probe fault	Probe open or shorted	Both relays drop out and the buzzer sounds. Any key mutes it. Clears once the probe reads again.
HH	Reading out of range	Temperature beyond the measuring range (STC-1000)	Outputs off and buzzer. Clears when the reading comes back in range.
Er	Settings did not save	Memory write error while saving, or a fault found at power-up	Returns to normal after about 3 s. At power-up, press any key to load defaults, then re-enter your settings.

How to enter service / parameter mode

STC-1000HX only: the keypad locks after 10 s idle (padlock lit). Hold the set key 3 s to unlock first.
Hold S / set for 3 seconds. The Set light comes on and F1 shows.
Step through F1 to F4 (F6 on the HX) with up and down.

Parameter list

Code	What it does	Range	Default / typical
F1	Set point	STC-1000: −50 to 99.9 °C. HX: −49 to 109 °C	10 °C
F2	Differential (hysteresis)	STC-1000: 0.3 to 10 °C. HX: 1 to 10 °C	STC-1000: 0.5 °C. HX: 3 °C
F3	Compressor restart delay	STC-1000: 1 to 10 min. HX: 0 to 10 min	3 min
F4	Probe offset	−10 to +10 °C	0
F5	°C / °F (HX only)	0 °C, 1 °F	0
F6	Network address (HX with RS-485 only)	1 to 127	1

How to change and save a setting

With the code showing, press S / set to see its value.
STC-1000: hold S and press up or down to change it. STC-1000HX: press up or down.
Press the power key (STC-1000) or set (HX) to save. Leaving it 10 s without a key press exits WITHOUT saving.

Other useful key presses

Task	How
See the set point	Tap up
See the differential	Tap down
Turn the controller off or on	Hold the power key 3 s

Notes

Cooling starts at set point + differential and stops at the set point. Heating starts at set point − differential and stops at the set point.
A flashing Cool light means the compressor restart delay (F3) is counting down.
The HX manual says to disconnect the load before changing F5 (°C/°F).

For licensed technicians only. This equipment can involve mains voltage, high-voltage microwave circuits, gas and refrigerant. Isolate power (and gas) before opening panels, follow the manufacturer's manual and your local licensing rules (for example ARC refrigerant handling and electrical or gas licences). Wrong settings can spoil food or damage equipment. Check every value on the unit in front of you before changing it.

Based on: Elitech STC-1000 operation instruction (V1.1) STC-1000HX-02 user manual (V1.0) and STC-1000X user manual. Always check the manual for your exact model and software version.

ServiceModes is not affiliated with Elitech or any other manufacturer. Written in our own words from the manufacturer's documentation.