Turn it on
- 1Push the dial (PUSH ON/OFF) once. The green ring and screen light up.
Unbranded ST-5400R in English
A room thermostat for a small ELECTRIC boiler: it switches the boiler's circulation pump and heater via a separate control box (ST-5300M), so every hour of heat costs electricity.
We could not find this exact model's manual, so these steps come from its closest sibling. If your panel behaves differently, send us a photo.
What does each button do?
- 1Current · 현재hyeonjaeRoom temperature now (17.0°C in the photo).
- 2Set · 설정seoljeongTarget temperature (21.0°C in the photo).
- 3Temperature-mode icon · 온도ondoLit when the unit is working to a room temperature target.
- 4Heating icon · 난방nanbangLit when heating/circulation is running.
- 5Temperature button · 온도ondoSelects temperature mode (heat until the room reaches 설정).
- 6Timer button · 시간siganSelects a time-based mode (likely run/rest cycling). Not verified.
- 7Away button · 외출oechulAway / low-temperature hold while you are out. Not verified.
- 8Dial: push = on/off, turn = adjust · PUSH:ON/OFFPush the dial to switch on or off. Turn left (−) or right (+) to change the set value.
What setting should I use?
19-21°C while home, about 10°C when out. Electric heating is expensive, so lower the target rather than running it high.
How do I…?
Heat the room to a set temperature
- 1Press 온도 so the 온도 icon shows.
- 2Turn the dial toward + until 설정 reads 21.0.
- 3Heating runs while 현재 is below 설정.
Leave for a few days
- 1Press 외출 before leaving (behaviour not verified). Otherwise turn 설정 down to about 10°C.
Turn it off
- 1Push the dial once more. Only do this when nobody is home for a short time and it is not freezing.
What do the words on the screen mean?
| 현재 | Current | Measured room temperature. |
|---|---|---|
| 설정 | Set | Target temperature. |
| 온도 | Temperature mode | Room-temperature control active. |
| 난방 | Heating | Heater/pump running. |
What trips people up on this model?
- This drives an electric boiler: high settings show up on the electricity bill, and Korea's residential tiered tariff (누진제) charges more per kWh the more you use in a month.
- If the screen works but nothing heats, the separate ST-5300M box (power + 순환펌프 lamps) may be off or tripped. Check its lamps.
Service line (Korean): Not printed on panel.