What must be done to the water tanks before testing water heaters?

Before testing water heaters, it is essential that the water tanks are filled with water. This is crucial because water heaters are designed to operate with a sufficient amount of water in them to prevent overheating and damage to the heating elements. An empty water heater can lead to dry firing, which can cause significant damage or failure of the unit.

Filling the tanks ensures that there is adequate water supply for the testing process, allowing for accurate readings and appropriate operation of the heater. This practice aligns with safety protocols and ensures that the testing procedure can be conducted effectively. Without water in the tanks, not only would testing be ineffective, but it could also pose hazards during the operation of the water heater.