English guide to Korean ondol floor heating controls

Here's a simple guide to using the control panel for the ondol (온돌) floor-based heating in your Korean apartment.

Typical Korean "ondol" (온돌) control panel for underfloor heating

Winter is starting and I saw some questions about this over on Reddit and Every Expat, so hopefully this can help you out. Scroll down to see some labeled sample control panels.


Many people, whether new English teachers or tourists visiting an Airbnb, arrive in Korea and struggle to get their heating and hot water working. All the buttons are in Korean, and the settings can be confusing. This type of heating system is fairly unique to Korea and parts of Asia, so I've taken a few different sample control panels and labeled the buttons for you. Plus I've translated some of the usual buttons/features with some simple explanations to help you get your room and shower piping hot and keep you from freezing to death in the coldest of Korea's four seasons.

It can be a little foreign to new arrivals to Korea, so let me take a minute here to explain a little bit about it.

Or jump down to the images if that's all you need.

What is ondol (온돌)? How does it work?

Almost all Korean houses and many buildings are heated by a system of hot water pipes that run under the floor. This is the "ondol" system. Space heaters, central heating ducts, and etc. are pretty uncommon. I read that heating via ondol (i.e. gas heating water that distributed underfloor) has a near 90% efficiency of gas-to-heat whereas electric heaters have just 40% efficiency. Although there is also pure-electric "ondol" nowadays too.

So anyway, here water is heated up in a boiler and pumped throughout this network of pipes to heat the rooms. If you're from the USA, you're probably used to the hot water heater just being always on and hot water available whenever you want it. In some smaller apartments though, you may need to manually (i.e. press a button) turn it on, or have it on a timer if it's not already, either for the hot water generally (for shower, sink, etc) or additionally for the under-floor heating pipes. It's usually two different settings for these two different use cases.

If it's summer, you'll want the boiler set to be "on" only in the morning (when you take a shower) for example, and you'll definitely want that hot water staying in the boiler and not pulsing through your house heating it up. But in winter you want that hot water circulating and warming the room.

Different houses/apartments will have different set ups and can vary a lot in how much "control" you have over the heating, as you'll see from the sample pictures.

Different modes of ondol

Something useful to understand is the difference between, generally, "silnae" (실내, interior), "nanbang" (난방, heating), and "ondol" (온돌, floor heat). Honestly I've been here a long time and still can't figure it out because these ideas are often interchangeable. But here's the basics:
  • Ondol (온돌) and/or nanbang (난방) usually refer to the temperature of the water itself.
    So if your panel lets you set a temperate based on this, then your water heater will work until the water circulating around your floor is that temperature. 
  • Silnae (실내) refers to the temperature of the room itself - the air inside the room. Setting a temperature like this will mean the water heater keeps working pumping that water hotter until the air temperature inside reaches that basic temperature. 


  • Setting temp based on "ondol" (floor) is better for people who sleep on the floor or for drafty houses (i.e. the heat of the water under the floor will be the temperature you feel laying on top of it. In a drafty house, specifying the water temp is good because otherwise the floor could get blazing hot trying to heat a room that stays chilly). This also applies to people who like to keep a window cracked for "fresh" air.
  • Setting temp based on "silnae" is better for people who sleep in a bed, or in enclosed well-insulated houses.

Don't take this too seriously though because plenty of ondol control panels don't even give you the option to choose between these types.

Just give me a TL;DR

I'm making this sound way more complicated than it is. The basic idea is this.

To heat your room in Korea,

  1. Make sure the water heater (boiler) is on. That will make hot water.
  2. Make sure either the "silnae" or "ondol" or "nanbang" heating is on. That will make the hot water circulate in the underfloor pipes. 
  3. Either leave it on to maintain the temp (if you want to kill your wallet) or set the timer/reservation to have it come on/off automatically. Or set it to "away" when you go out. Or just plain shut it off. 

Sample ondol control panels with English translations

Ondol control panel 1

Ondol control panel 2

Ondol control panel 3

Ondol control panel 4

Ondol control panel 5

Ondol control panel 6

Ondol control panel 7

I'm guessing that with this one above, the middle knob heats the room when turned to the right, but works on a timer when turned to the left (considering that there's no specific button/knob for activating a timer and that the left side is marked as "timer" mode without degree numbers while the right side has degree markings). That's a bit odd. So to heat the room, you'd want the power on, the bottom-right knob turned to the left, and the middle knob at the 2~3 o'clock position if you're home, 7 o'clock position if you're going out. 

Ondol control panel 8

This one gives you separate settings for all the modes. So in summer you'd want to make sure only the "hot water" setting is on (for your shower, sink, etc, but even then probably only in the mornings). In winter you'll want either the floor heat, or the room interior heat. If you'll be out in winter (whether for the day or even for a week or two) you can set it to "away" mode to keep it very low but on (to keep pipe water moving and above freezing). Not sure how you'd set the timer on this one but it's apparently an option. 

Typical ondol pipe setup for a multi-room apartment. Each valve controls water floor to a specific room. 

Translations of common functions / buttons on ondol control panel settings

Basic functions

  • 전원 - Power
  • 재가동 - Restart
  • 설정 - Settings
  • 기능 / 기능선택 - Functions, Mode selection
    This will be where you can cycle through things like floor heating, timer, away, etc.
  • 해제 - Cancel (e.g. cancel a timer)
  • 정지 - Stop
  • 운전 / 가동 - Operation.
    Usually indicated or lit when the boiler is currently heating.

Heating selections

  • 현재온도 - Current temperature
  • 희망온도 - Desired temperature
  • 설정온도 - Set temperature (i.e. desired temperature)
  • 저온 - Low / 중온 - Medium / 고온 - High
  • 난방 - Heating.
    This may mean "heating" generally or it might refer specifically to the temperature of the water in the underfloor pipes.
  • 난방수온 / 난방조절 - Heated water temperature.
    Referring to the desired temperature for the water pipes under the floor.
  • 수온설정 - Heated Water temperature (same as above)
  • 온수전용 - Water temperature
  • 실내 - Interior.
    Usually means the heater is running to get the interior "air" temperature of the room to the desired level. Contrast this with 온돌 or 난방수온. 
  • 실온 - Indoor (air) temperature
  • 온돌 - Floor temperature

Timer / Reservation settings

These can be interchangeable, so try it out to see what your panel offers. Generally, "timer" will be for a certain amount of time (5 hours, 10 hours, etc) and "reservation" will have the heat go on/off at specific chosen times (7:30am~10:00am etc). But I've seen them the other way round too.

  • 타이머 - Timer
  • 시간 - Time
  • 예약 - Reservation
  • 예약설정 - Timer reservation setting

Other modes

  • 취침 - Sleeping mode. I don't have this function so I'll assume it warms the room then reduces during the night.
  • 목욕 - Bath / Shower mode. Quickly heats up just the boiler to prepare for taking a hot shower.
  • 외출 / 전체외출 - Away mode. I don't have this function so I'd guess it lets the room get colder but maintains some basic non-freezing level of temperature to save energy.


  • 점검 - Error
  • 밸브/연소 - Valve / Combustion. In example #3 above, one of these will probably appear along with the "error" message to let you know what's wrong.
  • 물보충 - Replenish water (need to add water to the tank. Likely something you're going to want to ask a handyman about)

Specialized labels/modes

  • 방선택 - Choosing rooms. Only an option if your ondol system lets you specify rooms (by some assigned number) to heat.
  • 거실 - Living room
  • 방 - Room

More examples from other sources

This post is fairly old now, and is certainly not the only source for ondol control panel translations. Here are some other sites/blog posts from other sources that may have precisely what you're looking for. 

Be sure to click the associated links; most of these have several examples.

An example from the Every Expat in Korea Facebook group

Ondol control example from Easy to Learn Korean

Ulsan Online has some sample shots up like this up: Staying Warm in Korea | Ulsan Online

Some more modern boiler control panels are featured at How To Use Korean Floor Heating & Hot Water System - IVisitKorea

Stay warm out there

Hopefully this helped a few folks out there. Over on Reddit people will usually help you out if you can't get it working right. Here's an especially good example of folks helping out on a complex control panel: Please help me figure out my water heater. : korea

There are also plenty of YouTube videos (in Korean, sorry) that go through each type of control panel and demonstrate every single setting. If I had time, I'd go through them all and improve this post. But I'm just one man with work in the morning.

Finally you might also want to take a look at my same treatment of Korean air conditioner remotes:
10원 Tips: English guide to Korean air conditioner remote controls

Stay warm out there folks.


안녕하세요! 저희는 LMJ 엔터테인먼트입니다. 해당 게시물이 너무 좋아서 저희 최근 영상 설명에 Reference로 넣었습니다! 감사합니다!
Sam Nordberg said…
그럼요. 영상이 외국인들에게 도움이 되었으면 좋겠습니다. 그리고 저와 링크해 주셔서 감사합니다.