A Thorough ‘No Heat’ Check

For example, let's say you go on a service call for a gas furnace not heating. You find a bad fan motor capacitor, replace it, and restart the system. The problem you found was electrical, the system is heating and the homeowner is happy, so it's time to move on, right? Wrong! Dig a little deeper. Customers are going to be billed a diagnostic fee, so give them their money's worth.

Check the gas pressures, both inlet and manifold. Use your combustion analyzer to make sure the machine is burning clean and efficiently. Make any adjustments that are necessary to make the furnace operate at its designed and maximum efficiency. With ever-increasing energy costs, it's part of your job to ensure that customers aren't spending any more money than they must to heat and cool their homes.

A Thorough ‘No Cool’ Check

Six months later it's summertime. You go on a no-cooling call and find a bad contactor. You replace it and restart the system. Cool air is flowing and the homeowner has his checkbook in hand. However, you still have a little more work to do.

First, let the system run for a few minutes (15 by most manufacturer's recommendations) and check the refrigerant level. Most of us are guilty of cranking the machine up, slapping our gauges on, grabbing the suction line and adding refrigerant till the line is good and cold. The increase of the minimum SEER ratings and the use of the TXV has made the “beer can-cold” method for charging obsolete.

Fifteen minutes of run-time ensures that there is a full column of liquid at the TXV inlet and the system is stabilized and ready for accurate superheat and sub-cooling temperatures to be taken. Most manufacturers place a chart on the machine giving the value you need to look for. You can also take amp-draw readings on the vital components, give the system a thorough examination, and discuss with the homeowner any other services that your company may provide.

Wrapping Up the Call

Note on the invoice the operating conditions, temperatures, pressures, electrical values, and any items on the equipment that are operable but that may be nearing the end of their useful life. Include conditions of heat exchangers and coils. This gives the homeowner the information that justifies the billed amount. Your notes will also give the homeowner the information he or she needs to help make the decision about a replacement product. Arrangements can be made towards saving up for or securing financing for a replacement product in the near future. Of course, if there's a life, health, or property damage threat posed by the equipment, it must be taken offline until proper repairs can be made.

Troubleshooting steps can and should be used on equipment with printed circuit boards as well as the equipment's self-diagnostics. Although the boards themselves are not user serviceable, you'll still want to verify that they're diagnosing correctly.

The Technician's Responsibility

Proper troubleshooting skills increase customer confidence and make our companies more profitable. We can reduce costly callbacks and help keep equipment and parts costs lower. Many compressors and circuit boards returned under warranty are either not faulty or were damaged by another defect in the system that wasn't found, and repaired on an initial service call. Even though we're not billed for the warranty parts, they're not free: manufacturers figure the cost of maintaining in-force warranties into the price of parts and equipment. Reducing the number of warranty claims keeps our costs in check.

Technicians have a responsibility to customers, employers, and ourselves to ensure that we're well-informed and properly trained. Attend as many classes and seminars as you can. Equipment and technology change everyday, and technicians must stay informed.

And, I can't overemphasize the importance of North American Technician Excellence (NATE) certification in helping technicians reach the top.

Wherever technology takes us, we must keep our troubleshooting skills sharp. Those skills go a long way toward making us the best technicians this field has to offer.

Gary Hodges is the service manager at Carthage Heating & Cooling, Carthage, MS. He won the 2008 North American Technician Excellence (NATE) Certified Technician Competition, held at HVAC Comfortech 2008 in Atlanta. Hodges can be reached at 601/267-4611, or by e-mail at svcmgrgary@yahoo.com.