In our industry, technicians use many specialty tools to diagnose and repair system problems. These tools are necessary to accurately troubleshoot and repair malfunctioning systems.

However, there is a set of tools technicians should always use to help guide them in the right direction when troubleshooting: their senses. They will always need specialized tools to accurately diagnose a problem, but with the use of their senses, they can be more effective troubleshooters.

A good first step is to visually inspect the entire system, using no tools except perhaps a good quality flashlight. By doing this, a technician can easily determine if there is an obvious problem such as a dirty coil, broken wire, or similar fault.

This inspection will also aid a technician by allowing him to determine some of the system's characteristics, such as the type of metering device, the type of refrigerant used in the system, and the method used to defrost the evaporator.

Finding Leaks

If a system has a refrigerant leak, a technician can simply inspect the system components and piping for signs of oil. An oily spot is a telltale sign of a refrigerant leak in that area. He will still need a leak detector to pinpoint the leak, but he can save a lot of time by narrowing down the location by simply using his eyes.

Inspecting Motors

Bearing problems on motors can normally be heard as the motor operates. Technicians should pay attention to the sounds a motor or any system component generates as it operates. As the bearings wear, on many types of motors they will emit an unusual sound that many technicians can easily identify. Many technicians develop an acute sense for unusual sounds from motors, as well as other system components.

Pipe Touch

Technicians consistently measure pipe temperatures when servicing systems. Although a technician can never truly measure pipe temperature by simply touching its surface, he can gain a sense as to the temperature as compared to the range that it should be within. For example, on many applications the suction line should be cool to the touch and below that of the room's temperature.

By feeling the suction line, a technician may be able to get an indication if a problem exists. If the suction line should be below the room's temperature and it is not, it may aid a technician in diagnosing the system's problem.

Of course, technicians should be cautious of which pipes they are touching. Always use good common sense when exercising this practice. The discharge line can easily be over 150 degrees F on many systems and could cause injury if touched.

Making Sense

There are many other examples where a technician can rely on his senses to guide him in the right direction. A technician should not disregard the many benefits of using his senses to aid in troubleshooting a system's problem.

Joe Marchese is owner of Coldtronics, Pittsburgh. He can be reached at 412-734-4433,, or

Publication date: 08/01/2005