Underlying Problems That Get Missed
I ran a service call today with another tech where the previous tech had diagnosed an intermittent piston restriction. I read the history beforehand and for the past several years there were a lot of assorted comfort complaints and lot of little charge adjustments in both the Summer and winter, it is worth noting here […]
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How I Failed to Re-diagnose: And the Lesson I Learned
  This is the tale of how I found myself stuck on a service call for over 12 hours on a weekend, due to my failure to re-diagnose an issue. I was working for a service company that had many accounts with local gas stations. These were large customers, and we did everything we could […]
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Wide, Narrow, Wide Diagnosis
When you walk up to a piece of equipment you want to follow a process to ensure that you accomplish five things. #1 – You diagnose the fault correctly #2 – If possible you find the “why” of the failure #3 – Find any other problems or potential problems with the system that can cause […]
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The HVAC/R Diagnosis Pyramid of Skill
WARNING: THIS ARTICLE CONTAINS GENERALIZATIONS. IT DOES NOT APPLY TO EVERYONE AND WE HAVE ALL PROBABLY BEEN ALL OF THESE AT ONE POINT OR ANOTHER. IF YOU FEEL PERSONALLY ATTACKED MAY I SUGGEST FINDING A SAFE SPACE AT A WEST COAST UNIVERSITY AND BORROWING A BINKY FROM A NEARBY TODDLER. ALSO… MY CAPS LOCK BUTTON […]
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Famous Last Words (Before a Callback)
  You've probably heard the famous last words “Dude, watch this” before a concussion, burn, shock, broken bones or some other bodily harm. This phrase has become synonymous with young guys doing something dumb to impress their friends. Technicians have two common phrases that may not lead to bodily harm (although sometimes it might) and they […]
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Use Your Senses First
A good technician uses their senses before they use diagnostic tools. Is your suction line abnormally cold? Make sure the evaporator coil isn't frozen, and inspect for obvious airflow issues like a dirty filter or evaporator coil. Is your liquid line abnormally warm to the touch? It could be a dirty condenser, condensing fan issue, […]
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Troubleshooting For HVAC/R – Gathering Data 
This article is part 3 in a 5-part series by Senior Refrigeration and HVAC Technician Jeremy Smith. Let's start with step#1 in the flowchart: Gather data. This is why we spend money on those fancy digital manifolds, shiny electrical meters, and other gadgets, widgets, and doodads. It isn't to brag about them on Facebook; it's […]
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Troubleshooting For HVAC/R – The Don’t List
This article is the second in a 5-part series by Senior Refrigeration and HVAC tech Jeremy Smith.  The Ground rules I've spent some time thinking about troubleshooting and the processes and procedures that I use to find problems. Not the “why isn't my air-conditioner running?” problems, but the “Things just aren't quite right”-type problems—the really […]
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The Troubeshooting 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 […]
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