HVACR technicians are special individuals. They have the intelligence, aptitude, and knack for problem-solving. In fact, they are expected to know how to diagnose and troubleshoot equipment of all types, sizes, and ages. However, they don’t just show up and automatically know what the problem is and how to solve it. Instead, they turn to their favorite diagnostic tools to point them in the right direction.


The diagnostic tool technicians reach for may vary greatly depending on personal preferences or the types of equipment they will be troubleshooting and servicing on a call.

“Picking one tool would be tough,” said Greg Spears, owner, Horizon Air Heating & Air Conditioning, Henderson, Nevada. “I use my multimeter on every call, and my dual temperature Fluke 52 thermometer with two pipe clamps is a close second.”

Jim Crist, a commercial project manager in Salisbury, Maryland, said he recommends two go-to tools —  a dual temperature probe to diagnose temperature split, and a volt meter.

“With those two items and a screwdriver, I can diagnose almost any system,” he said.

Chuck Blouse, sales engineer at Williams Service Co. in York, Pennsylvania, agreed.

“These three items, and the knowledge of how to utilize them properly in making a diagnosis, are basic tools for all technicians,” he said. “I would only add that the volt meter be a combination with an amp meter attachment.

“In the HVACR field, everything operates on having the proper airflow, whether it be in the ductwork or exhausting the proper amount of air through a heat exchanger,” Blouse continued. “And, all equipment utilizes electricity and its components, so we need to look there as well. We can diagnose nonoperating equipment with the volt meter to find out where the electrical signal is stopping. Once we find that issue and it is resolved, we can then use the amperage meter to determine if we have heavy electrical load issues. If there is no problem there, we can determine if we are moving the proper amount of air by checking the temperature rise across a heat exchanger or the temperature drop across a cooling coil with the dual temperature probe. Only after those items are checked and verified do we need to start getting other tools out for a more complete diagnosis, if still needed.”

According to Tom Turner, environmental program coordinator, Austin Energy, and owner, Air Evangelist, Cedar Park, Texas, it really depends on if the system is running or not.

“If responding to a service call, I would choose a multimeter if the system is not running or a manometer if the system is running,” Turner explained. “Since over 80 percent of systems in our region have airflow issues [poor duct, restricted intake, etc.], I need to know airflow deficiencies prior to adjusting refrigerant levels. If airflow is wrong, everything is wrong. It decreases efficiency, comfort, and shortens equipment life.”

Vincent Albano, VRF product manager, Russell Sigler Inc., Orange County, California, said his must-have tools are the Fluke 179 True RMS Digital Multimeter and a set of gauges.

“With today’s equipment and technology in units, a lot of techs have basic meters that don’t read certain voltages, resistance, etc. on lower scales,” Albano said. “The Fluke 179 meter has all that you would need to assist in troubleshooting. Having the right tools saves you time and helps you be precise. Knowing how to use it also is important. And refrigerant gauges are a given because every HVACR tech needs this to check the refrigeration circuit.”

James Duffy, refrigeration and air conditioning mechanic, Bouchier – Carillion Group, British Columbia, Canada, said he uses his multimeter/clamp meter more often than gauges.

“Those two meters are my first choice tools for a couple of different reasons,” Duffy said. “First of all, I work in a very safety conscious environment, and one of our golden rules is ‘proving zero energy’ prior to starting work [with the exception of electrical troubleshooting]. So, we always have to lock out a piece of equipment and then use a meter to prove no voltage/zero energy. Secondly, it’s because so much of the equipment requires electrical diagnostics to check operation. Things, like mechanical issues [e.g. failing bearings] and, to a lesser extent, temperature issues, I can get an idea of the state by observation, listening, touching, etc. And I’m an HVAC guy in an industrial setting, so I can see tradespeople who are on the refrigeration side of things having quite a different opinion on tools of choice.”

Additionally, not all technicians’ favorite tools are handheld instruments.

“I love the RefTech app,” said Jeff Pelletier, service technician, Mechanical Services Inc., Thomaston, Connecticut. “I don’t work on refrigeration a lot, maybe five or six times a year, so I look to others with more depth and experience when I run into issues I can’t resolve. The app is a resource for me — a tool, if you will. Information like ‘less than 5°F superheat indicates a flooded TXV [thermal expansion valve], or ‘the condenser split for a high efficiency condenser is about 20°’ is excellent for a guy with limited refrigeration knowledge. I don’t see the app as an ‘all I need to know,’ but as a resource to help me diagnose.”

Bill Russell, HVAC/R lead technician, Advanced Mechanical Plus, Lima, Ohio, also likes the RefTech diagnostic app for commercial refrigeration walk-ins and reach-ins.

“The one thing I really like about the app is it’s that second opinion some of us need when we have been looking at an issue too long and need to call another tech to get us on the right track,” he explained. “It’s that voice of reason when it’s late and cold, and you’ve been there for three hours more than you should have and haven’t had any lunch yet. I also like that the app tells you when there are multiple issues and when you need to recheck your information.”

But instruments and apps are not the only tools available to techs, according to Jeff Fordeck, director, Global Business Development & Planning, Tecumseh Products Co.

“The best and most important tool for a technician does not come in a toolbox,” he said. “Your five senses are a must for every job and are the first source of input on where to start looking for a problem.” 

Publication date: 3/19/2018

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