No, the tap water is not drinkable in Beijing. Hotels rooms often feature a water dispenser, which delivers both cool and hot potable water. However, some of hotels have no water dispenser but are instead equipped with a water heater/hot pot, which you must use to boil tap water before drinking it.
In some cases, hot water is provided in a thermos in the guest room, and four or five-star hotels may supply high-quality mineral water for free or for a minimal charge. Ordinary bottled mineral water and various beverages are commonly sold in many street shops, supermarkets, restaurants and hotel stores.
Some top-notch hotels can offer potable tap-water. Therefore, tourists should ask the hotel whether the running water can be drunk or not. Boiled water is provided in the hotel room.