What should be done after cleaning or replacing the filtering element in a combustion heater fuel system?

After cleaning or replacing the filtering element in a combustion heater fuel system, it’s essential to pressurize the system and check all connections for leaks. This step is crucial because once the new or cleaned filter is installed, the system needs to be tested for integrity and proper function.

Pressurizing the system allows for the detection of any leaks that may not be visible when the system is depressurized. A leak in the fuel system can lead to serious safety hazards, including fire risks and potential equipment damage. By checking all connections during this pressurization, one ensures that the new or clean filter is correctly installed and that the system is sealed securely.

The other options do not serve the same critical purpose. Allowing the system to cool down, for example, is not necessary after filter maintenance unless specifically stated by the manufacturer, as maintenance tasks can generally be performed safely regardless of the operating temperature, provided safety protocols are followed. Leaving the system unpressurized does not contribute to ensuring that the connections are secure. Reinstalling the old filter element would contradict the intent of maintaining the fuel system and might impact performance and safety.