Tag: Diagnosis

 

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 are –

“That’s Good Enough” and “That’s Normal” 

Pulling a vacuum for 30 minutes without a micron gauge and then “That’s good enough”.

Doing a standing pressure test and the pressure keeps dropping JUST A LITTLE and “That’s normal”.

Running a 0 superheat and “I see that all the time” followed by some made up reason about this particular equipment, or load conditions.

I have heard lot’s of made up explanations over the years… some of them out of my own mouth and almost all of them being used as a justification for something being good enough or normal.

 

Don’t misunderstand, normal and good enough are both real concepts, but they need to be backed by deep understanding of the equipment you are working on (have you read the entire installation instructions and / or service manual?) and the readings you are taking (Do you understand what they mean, why you are taking them and how your test instruments / tools work?).

If you can’t follow it up with “It’s normal because…..” or “That’s good enough because….” with a real answer, not a made up reason, then you need to keep working.

This is a journey for all of us, but stop for one second and be honest with yourself. When you get frustrated, short on time or feel in over your head… Do you ever use these phrases? If so, congratulations. You are in an elite group of techs  willing to admit what you don’t know.

Now repeat after me…

“I will no longer make excuses for what I don’t understand, I will stop and work to understand what is actually going on until I have it mastered”

 

— Bryan

 

P.S. – Sorry for the repeat after me thing… It’s a bit too much, but this whole article is nerdy as heck so I figured I would just take it all the way.

A good technician uses their senses before they use diagnosis 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? Could be a dirty condenser, condensing fan issue or overcharge.

Listen for abnormal motor and compressor noises, watch for signs of corrosion and oil for possible leaks.

Smell for signs of burning lacquer  which can signal burned motors or controls.

Listen for a blower that sounds like a train engine (If it’s an ECM it could be an airflow restriction) .

Train your senses to spot abnormalities and you will save time and catch issues before you need to pull out tools for confirmation.

This isn’t to say that you shouldn’t use diagnostic tools, just that you will save a lot of time if you use the best tools of all first.

–Bryan

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 to find problems better and faster than someone else.

So, before you start trying to change things, start by gathering and recording data. Inspect filters, inspect coils. Look over the wiring. Check your voltages, resistances, airflow, pressure readings, temperature readings. Locate any open switches in the control circuit and try to determine WHY that switch is open. A pocket notebook is nice but, for larger problems, I’ve taken to carrying a full sized college type notebook.

This gives me more room on the page to write my notes, draw pictures, scribble thoughts and observations about the equipment I’m working on.
Write down every measurement and reading. EVERYTHING. Even if you find that capacitor blown up and you “just know” that’s the problem, take your time and keep looking.
Before we leave the Data Gathering step, we do need to take whatever steps are necessary to get the equipment running if it isn’t already and gather another set of data
Once you have all this data together, we can proceed to Step #2. Analysis.

— Jeremy

 

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 difficult ones.
I’ve boiled it down to a sort of flowchart to simplify things and we’ll take the flowchart
step-by-step, explaining each step as we go along.
Something to keep in mind as you read this. There is no step by step, color by numbers guide
to troubleshooting. I’m not trying to give you a magic wand to wave at broken air conditioners
because such a thing doesn’t exist. Troubleshooting is more of a “can do” attitude combined
with experience and some applied critical thinking.
First thing, let’s start with a couple of “Dont’s” when troubleshooting.

#1. Don’t rush

Yes, I know that many of us get piled up under a load of calls and can
be pressured to rush through them to get home to the family. Yes, I know the boss or dispatcher (or both) are calling
you every 10 minutes asking if you’re done and ready to move. Yea, I know the customer is
breathing down your neck to get the machine running. This is probably the hardest part of
troubleshooting. You NEED TO block that stuff out. You need to take your time and work
through the problem methodically.
#2. Don’t assume

Follow your troubleshooting procedure through to the end. Taking
shortcuts is almost as bad as allowing yourself to be distracted.
Over the course of a couple of articles, I’m going to share my troubleshooting processes and
procedures and hopefully give you some tips to build a process that will help you to be better.

Part 3 is coming tomorrow

— Jeremy

 

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, 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 and he went on to his job and I went to have a chat with the trouble unit.

20 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. Put it in a box in my head, closed the lid and locked it.

I dug out the basic Trane “Service Facts” book and 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 diagnose 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 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 manufacturers 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)

This article was written by Senior Refrigeration Tech Jeremy Smith. Before we get to it I want to remind you that ALL of the tech tips are available in alphabetical order HERE – it’s a great link to share with other techs, HVAC business owners, Trade school students etc… you can feel free to share these anywhere.


Alright, maybe “advanced” isn’t the right thing to call this little tidbit, maybe it should be “troubleshooting and information sharing in the digital age….”

Microprocessor controls, PCBS, PLCs, call them what you will, electronic circuit boards have become an integral part of the HVAC/R world. From a small heat pump defrost board to an advanced building automation system, these little pieces of equipment seem to be the bane of a techs existence.

One very important thing to remember when working on a system with one of these items installed is that each one has a specific troubleshooting procedure and its own sequence of operations.

So, how is a tech supposed to remember all of this stuff?

Pro Tip.

You DON’T.

Chances are good that you’re reading this on a smartphone or a tablet. With that and a couple of free apps, you can build a library of tech manuals, reference documents and other information to allow you to be better at diagnosing problems on specific equipment.

 

So, how do we build this? Well, you can go Old School and print out all of the manuals and store them in your service truck, or we can keep up with the times and go HVAC/R School and put it in “The Cloud”.

 

Everybody has a Gmail account. Maybe it’s your primary email, maybe it’s the one you give people that you don’t really like so you never hear from them again. Well, with every Gmail.

account comes 15GB of free online storage through an app called Google Drive. Grab the Google Drive app from the app store or play store and, if your Gmail is logged in to that phone, the drive app is already logged in to access your cloud storage. Now, start to “build” your reference library by uploading those PDF files to the drive.

Sometimes this is easier to do on a PC, but it can be done from a phone or tablet as well, it’s just a bit more tedious, at least for me. Then, the next time you’re on a job and have to search and find a manual for a piece of equipment you’re working on, save it to your Google Drive, too. Before long, you’ll have a very
nice library to draw from.

If you’re feeling particularly generous, within Google Drive, you can share that information with co-workers and other techs. You can either allow them to contribute to the library or just to view
it.

You know what’s better than having a good memory? having good resources. Oh and reading… you pretty much can’t be a good tech nowadays if you never read.

Sorry…

— Jeremy

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 inefficiency, low capacity, failure, safety or indoor air quality issues

#4 – Communicate clearly with the customer and and office about these issues via paperwork and / or verbal communication

#5 – Execute and repair the issues in an efficient and workmanlike manner

In order to accomplish this I recommend looking at the equipment with a wide, narrow, wide mindset

First, speak with the customer, read the call history, understand any concerns the customer may have and any past failures. Look at the equipment, look for any obvious signs of issues like oil stains, corrosion, rubbing wires, bloated capacitors etc…

Then go narrow and FIND THE CURRENT PROBLEM. The difference between a “Sales Tech” and a real service tech is the ability to quickly and accurately diagnose the problem at hand as well as find the likely causes of the failure.

Finally, once you find THE problem, go wide again and look for any other problems BEFORE communicating with the customer. Look at coils, contactors, capacitors, filters, belts, wire connections and potential rub outs, check coils and acummulator for oil stains etc…

When looking wide take the mindest that..

– The system was likely installed poorly / incorrectly to begin with

– Every other repair made to the unit was done improperly

This will put you in the mindset to double check everything.

Now you are ready to talk to the customer and make repairs with confidence.

— Bryan

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