When November comes, international students often ask me about this. "You want me to leave the boiler on when nobody's home? Isn't that a waste?" They get confused because the boiler has an 'Away' button instead of just 'Off'. ## 'Away' doesn't mean completely off Away mode doesn't stop the heating; it's a function that keeps the house at a low temperature, just enough so it doesn't get too cold. That's because many homes in Korea use ondol, a system where water runs beneath the floor. Once the floor and walls have cooled down completely, it takes a long time to heat them up again. Also, when it gets very cold, the water inside the boiler and the water pipes can freeze and burst. This is called 'dongpa' (freeze burst). So even when Koreans leave home for a few days in winter, they don't turn off the boiler and leave it on "out mode." ## So does it really save money? It makes a big difference depending on how old the house is, how well it's insulated, and whether the heating is individual or central. You can't say that going out mode is always cheaper. But when you're only stepping out for a short while, people often say that going out mode is better than turning the heating off. Even when you're away for several days, on days when the temperature drops below freezing, burst pipes are a bigger worry. Because the repair bill can be higher than the heating bill. ## Check it today - Look for words like 'Heating', 'Away', and 'Reserve' on the boiler controller. - For the first month, don't set the heating temperature too high, and adjust it after checking your bill a month later. - If you don't know what a button does, ask your landlord or the management office. You can also find the user manual on the boiler manufacturer's website. In some apartments, the heating cost is included in the maintenance fee. Check your contract or your maintenance fee statement.