Usually, power flushing a central heating system generally takes about 5 to 6 hours. In some cases, the technician takes about 8 hours to two days. This time taken completely depends on the condition of the system and the issues detected. The more the number of radiators, the more time it takes to service them. If you provide timely service to your central heating systems, there is nothing much to worry about, and the servicing won't take much time. A span of five to six hours is enough for the process of power flushing. For those who cannot detect early symptoms or have failed to provide a power flush servicing for more than the required time, the service process may take up to 2 days. The longer the gap in service, the more complicated it gets. Also, a long delay in power flushing services will increase maintenance costs.