The Troubleshooting Mindset

This article was written by Senior Refrigeration tech Jeremy Smith. Big thanks to Jeremy for his contributions to HVAC School and the tech community.


Having spent many years in the trade and many years reading posts from techs on forums and social media, a big issue that I see is that troubleshooting is something of a lost art.

Troubleshooting is where the rubber meets the road for a service technician. Nobody cares what certifications you have, what union you belong to, or anything else. If you can't find the problem and solve it in a timely fashion, your customer and employer are not going to be happy.

One of the things that I think most guys struggle with is the mental aspect of troubleshooting. I'll relate this in the form of a recent call I was sent on to “clean up.” It was a no-heat call in a small convenience store. Trane RTU on a zone sensor.

The tech called me and related that the unit had a call for heat at the unit, but the ignition sequence didn’t start. We talked a little about the problem, and he checked some limits and a few other things. He wound up ordering an ignition board and limit sensors. These were replaced late that night, and the unit still didn't work.

I was sent the next morning. Now, we get into the mental part of troubleshooting.

I met the tech so that he could communicate the basics of what he did. We talked for about 10 minutes before he went on to his job, and I went to have a chat with the trouble unit.

Twenty minutes later, I had the problem solved. I found a failed RTRM board. Now, you guys that do Trane all the time probably aren't surprised, but let's analyze what went wrong and how this could have been handled on a “one-stop” basis.

What did I do that the first tech didn't?

For starters, I took everything that I was told about the unit: what it was and wasn't doing and what everybody and their brother thought was wrong with it, and I threw it all out. I put it in a box in my head, closed the lid, and locked it.

I dug out the basic Trane “Service Facts” book, started the troubleshooting procedure from Step 1, and followed it to the end.

Now, I can make these arrogant claims about how I'm a Billy Badass service guy and how I'm more awesome than anyone else, but the simple fact is that I'm not. I do things a little differently and think a little differently than many others, and that sets me apart.

What did the first tech do wrong? While I'm not in his head, I think that he focused on why the heat didn't work instead of taking the unit AS A WHOLE and diagnosing it as a whole—kind of like the guy who can't figure out why the fridge is warm and spends an hour working on it only to find the plug pulled.

So, the mental aspect of troubleshooting cannot be ignored.

Start at the beginning, work the process and troubleshoot the entire system. Being willing to read the manufacturer's troubleshooting info isn't a newbie move; it shows maturity.

Work on the troubleshooting mindset. Don't be a parts changer.

—Jeremy

(Edited by Bryan Orr, any mistakes are my fault)

3 responses to “The Troubleshooting Mindset”

  1. Nice job and on target.

    I’d like to add that perhaps the 1st step in troubleshooting is recognition that it is our own ego which prevents cognitive, logical thinking. Particularly men, who seem to subconsciously fall into the roll of “road warrior.” Saviors of women, children, and the occasional damsel in distress!

    The road warrior attacks the problem head-on, in the middle of the problem, where chaos abounds. When he gets stuck and confusion prevails, he attacks again with a bigger, better multi-meter, or maybe just his best guess.

    As indicated in the article, the mature technician starts at the beginning, where order and logic can be found. He then the works through process one step at a time, while keeping a watchful eye on the entire system. When he gets stuck, he starts over again…from the beginning. With each repeat of the troubleshooting process, he cements his understanding of the sequence of operation, which brings him closer to the truth. I call this technician, the “wise warrior.”

    Simply put: To start at the beginning, can only lead to the end. 🙂

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Related Tech Tips

Key Soft Skills for Technicians
  As with most other trades, HVAC/R technicians need to have a solid set of hard skills to make it in the industry. Whether we pick up those hard skills by working on cars as teenagers, learning them in a trade school, or acquiring them on the job, we’ll have to rely on our hard […]
Read more
Modulation Motors
Modulation motors are not often seen in residential equipment, but we see them a lot in commercial and industrial applications on many different types of equipment. I see them primarily on larger burners to control the fuel firing rate, but they also control water flow through heating coils, the water level on cooling towers, and […]
Read more
TH, TR, and TH/TR Gas Valve Terminals
Jesse Grandbois is one of the techs who reads the tech tips, and he wrote a few tips that he wanted to share on some gas furnace control basics. This tip is about the basic terminal designations on a typical 24v gas valve. Thanks, Jesse! Have you ever noticed the TH/TR terminal on a gas […]
Read more
loading

To continue you need to agree to our terms.

The HVAC School site, podcast and daily tech tips
Made possible by Generous support from