The timing for drainage cleaning to unclog a blocked drain varies depending on the drain, age, and blockage severity. On average, it takes one to two hours. However, it’s not always possible to provide an exact time for unclogging blocked drains as it can depend on various factors. Some companies may promise to complete service in one hour or less, but it’s essential to remember that the time it takes can vary. At Hummingbird Technical and Cleaning Services, we aim to provide sewer cleaning service in one or two hours.