HVAC
B y C ar ol Fey
Carol Fey is a technical trainer who has worked as a heating mechanic in Antarctica and has published six books for the HVAC/R industry. She can be reached at carol@carolfey.com, or visit her website, www.carolfey.com.
T
here is an old joke in the HVAC business that the instructions that come with a control are good only for lighting the pilot. The thing is, sometimes if you learn how to interpret what’s printed on that paper, you’ll learn why the pilot won’t stay lit. A fine example of this is a troubleshooting chart. It leads you effortlessly through the steps of solving a problem.
Making the most of troubleshooting
The troubleshooting chart is the perfect tool for technicians. Technicians are often are black and white thinkers. The answer is either “yes” or “no.” That’s how a troubleshooting chart thinks.
CHARTS
A troubleshooting chart is a flow chart. It shows a sequence of steps in a particular order. There are a few simple rules: You must start at the beginning. Starting in the middle can get you the wrong answer. You may not skip steps, even if you think they’re silly. You have to answer the questions honestly and without guessing. We mostly don’t like rules, but these are a small price to pay for getting to the right answer.
FOLLOWING THE PATH
In any troubleshooting chart, the pattern is: 1) A question or statement;
YES
2) A choice of yes or no; and 3) An action to take or a new question, depending upon the yes or no choice.
DOES THE DARN THING WORK?
DON’T MESS WITH IT
Looking at our cheeky troubleshooter’s chart, let’s start at the top and see where the answers take us. The first question on this char t is, “Does the thing work?” We need only to choose “yes” or “no.”
YES
DOES ANYONE KNOW?
“Yes” takes us to the action “Don’t mess with it” and straight down to the final resolution, “No problem.”
NO
DID YOU MESS WITH IT?
NO
YOU POOR FOOL
NO YES
“No” brings the new question, “Did you mess with it?”
YES
“Yes” takes us to the piece of information “You fool,” and to a new question, “Does anyone know?”
HIDE IT
The two answers to the question lead in two different directions. “No” goes to the instruction “Hide it,” and to the final resolution, “No problem.” “Yes” leads down an entirely different path. Have fun working through the various pathways, but watch out for the infinite loop. That’s where we just keep going around and around in a pattern. A real troubleshooting chart shouldn’t have any infinite loops. But seeing it in this one f eels a little like real life, doesn’t it? We can’t get out of the loop until w e answer the question “yes.” Then we can move on to “No problem.”
YOU POOR FOOL
WILL YOU CATCH HECK? NO
FORGET ABOUT IT
NO CAN YOU BLAME SOMEONE ELSE? YES NO PROBLEM
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