Turn it on
- 1Press 전원 (big round button, bottom right). The heating or hot-water lamp lights.
Lotte R01 (round red-LED display) in English
An older cream Lotte panel with a round red number display, four mode buttons in an arc, ▲▼ on the right and a big power button at the bottom.
What does each button do?
- 1Set temp · 온도설정ondo seoljeongEach press switches which setting you are changing: heating ↔ hot water. Then use ▲▼. After 5 s the display returns to the current water temperature.
- 2Burning lamp · 연소yeonsoRed lamp lights while the boiler flame is on.
- 3Display · 표시창pyosichangShows the current heating-water temperature, settings while you change them, or an error code.
- 4Heating lamp · 난방/온수 램프nanbang/onsuGreen lamp: heating + hot water mode is on.
- 5Heating + hot water · 난방/온수nanbang/onsuTurns heating on (hot water still works). Heating range 45–80°C.
- 6Hot-water-only lamp · 온수전용 램프onsu jeonyongYellow lamp: hot water only, no heating (lit in this photo).
- 7Timer lamp · 타이머 램프taimeoLights when the timer is on.
- 8Hot water only · 온수전용onsu jeonyongSummer mode: heating off, hot water only.
- 9Up · 상 ▲sangRaises temperature or timer hours.
- 10Timer / Away · 타이머(외출)taimeo (oechul)Repeating timer: 20 minutes on, then off for 1–24 hours (set with ▲▼).
- 11Down · 하 ▼haLowers temperature or timer hours.
- 12Service number · A/S 1588-8888ei-eseuLotte service line as printed.
- 13Power · 전원jeonwonOn/off. Also used to reset after an error.
What setting should I use?
Heating 60°C while home; timer 03 (3 h) when out for the day, 02 in sub-zero weather; hot water 60.
How do I…?
Use floor (ondol) mode
- 1Press 난방/온수 (second button). The green lamp lights.
- 2Press 온도설정 (top-left button) until the heating setting shows.
- 3Press ▲▼ to 60 (range 45–80°C). Wait 5 s; it saves.
Leave for a few days
- 1Easiest: set heating to 45°C. Users report 45 acts as Away: about 30 min on, 3 h off.
- 2Or use the timer (see timer).
Run on a timer
- 1Make sure heating (난방/온수) is on and set, e.g. 60°C.
- 2Press 타이머(외출). Hours blink.
- 3Press ▲▼ to choose 1–24 hours, e.g. 03. It runs 20 min, then stays off that many hours, and repeats.
- 4To stop the timer, press 난방/온수.
Hot water only (summer)
- 1Press 온수전용 (third button). The yellow lamp lights; heating is off.
Change the hot-water temperature
- 1Press 온도설정 until the hot-water setting shows (in 온수전용 mode press it once).
- 2Press ▲▼. Six steps: 45, 50, 60, 65, 70, 80°C. 60 is usually enough.
Turn it off
- 1Press 전원.
What do the words on the screen mean?
| 연소 (red) | Burning | Flame on. |
|---|---|---|
| 난방/온수 (green) | Heating | Heating + hot water mode. |
| 온수전용 (yellow) | Hot water only | No heating. |
| 타이머 (orange) | Timer | Timer cycle on. |
| two-digit number | Water temp | Current heating-water temperature — not room temperature. |
What trips people up on this model?
- The number is boiler-water temperature, not room temperature — there is no room thermostat mode.
- Pressing ▲ once past 80 gives 급속 (84°C fast heat), only right after power-on.
- If the yellow 온수전용 lamp is on, heating is off — the most common 'my boiler is broken' mistake.
- Lotte left the boiler business in 2020; spare parts are now scarce and the printed number may not reach Lotte service. Ask your landlord first — repairs often mean a boiler replacement.
It shows an error. Now what?
Error codes show in the round display. On many Lotte boilers P4 / P6 mean leak / water refill; press 전원 off/on once, and if it returns call your landlord.
Service line (Korean): 1588-8888