The answer to 'my duct cleaning keeps shutting off' is that there are several common causes, including overheating, clogged filters, and electrical issues. This could be a sign of a more serious problem with your HVAC system that requires professional diagnosis and repair.
One of the most common reasons a duct cleaning system keeps shutting off is overheating. The motor or other components can overheat if the system is run for too long, if there is a blockage restricting airflow, or if the system is not properly maintained. This causes the safety mechanisms to kick in and shut the system down to prevent damage.