Seeing Is Believing: Check the Evaporator Coil
But visually inspecting the coil is not always easy. The evaporator coil is usually enclosed in some type of housing, making it hard to inspect. It can also be mounted high up, as in the case of a large walk-in cooler or freezer, making it even more difficult to inspect.
On a running system that is not cooling properly, most technicians will install their service gauges on the system and read both the suction and discharge pressures. A system with a completely iced-up coil will show lower than normal suction and discharge pressures.
Technicians could easily misdiagnose this condition as a system low on charge if they do not visually inspect the evaporator coil. If there is this misdiagnosis, and refrigerant is added to the system, they now have overcharged the system and have created an additional problem.
It is vitally important to visually inspect the evaporator coil when troubleshooting a system with lower than normal suction and discharge pressures.
Visual InspectionsVisually inspecting the condition of the evaporator coil will aid the technician in determining if the system:
Marchese is the owner of Arctic-Air Refrigeration, Pittsburgh, PA.