It’s Okay Not to Know
The Apprentice Doesn’t Know He Doesn’t Know. The Journeyman Won’t Admit He Doesn’t Know. The Senior Tech Says It All the Time.
There is a fascinating progression that happens during an HVAC technician’s career.
It has nothing to do with tools.
Nothing to do with certifications.
Nothing to do with how many compressors you’ve changed or how quickly you can calculate superheat.
It has to do with three words:
“I don’t know.”
At the beginning of your career, you don’t say them very often.
Then you reach a point where you absolutely refuse to say them.
And eventually, if you stay in the trade long enough, you say them all the time.
It’s one of the strangest full-circle moments in becoming a tradesman.
Because generally:
The apprentice doesn’t know that he doesn’t know.
The journeyman knows he doesn’t know but would rather die than admit it.
And the senior technician?
He’ll tell the homeowner, the apprentice, the service manager, the manufacturer and three guys at the supply house:
“I have no fucking idea.”
Then he’ll figure it out.
Welcome to HVAC.
Stage One: The Apprentice Knows Everything
This stage usually begins somewhere around six months.
The first few weeks are terrifying.
Everything is new.
Wires everywhere.
Gauges.
Meters.
Compressors.
Contactors.
Transformers.
Blower motors.
Refrigerant.
Superheat.
Subcooling.
Static pressure.
The journeyman might as well be performing surgery.
Then something happens.
You start understanding things.
You learn the refrigeration cycle.
You can use a meter without asking which setting it goes on.
You know what a capacitor does.
You’ve replaced a contactor.
You’ve changed a blower motor.
You’ve hooked up gauges.
You diagnosed your first bad capacitor all by yourself.
And suddenly you have a realization:
HVAC really isn’t that complicated.
Oh, sweet child.
Enjoy this period.
It won’t last.
Everything Has an Answer Now
No cooling?
Capacitor.
Frozen evaporator?
TXV.
Low suction pressure?
Needs Freon.
High head pressure?
Dirty condenser.
Thermostat blank?
Float switch.
Compressor won’t start?
Capacitor again.
Honestly, you’re starting to wonder why the journeyman makes such a big deal about this job.
You’ve got a meter.
You’ve got gauges.
You’ve watched 47 YouTube videos.
Let’s fucking go.
There is only one small problem.
You don’t know enough yet to understand how much you don’t know.
Then HVAC Humiliates You
It always happens.
Eventually you meet The System.
Every technician remembers some version of The System.
It doesn’t behave like the other ones.
Your pressures don’t make sense.
Your temperature readings don’t make sense.
The electrical readings seem fine.
You’ve checked everything you know how to check.
So naturally:
TXV.
Because the TXV is the patron saint of technicians who have run out of ideas.
You proudly announce your diagnosis.
Then the journeyman arrives.
He looks at the equipment.
Looks at your gauges.
Looks at you.
Looks at the blower door lying on the floor.
“Did you take those readings with the door off?”
…
Maybe.
He puts the door back on.
Airflow changes.
Pressures change.
Everything you just diagnosed changes.
You quietly remove your gauges.
Today HVAC has taught you something.
You are not nearly as smart as you thought you were this morning.
This is good.
Painful.
But good.
Welcome to Stage Two: The Journeyman
A few years pass.
Now you actually know some shit.
You’ve seen failed compressors.
Restricted metering devices.
Refrigerant leaks.
Airflow problems.
Electrical problems.
Control problems.
Drain problems.
Duct problems.
You’ve seen blower wheels that look like somebody covered them in brownie batter.
You’ve seen contactors welded shut.
You’ve seen homeowners install thermostats with wiring strategies that appear to have been inspired by abstract art.
You’ve seen enough things go wrong that you start recognizing patterns.
And pattern recognition is powerful.
The homeowner tells you what happened.
You already have three possibilities in your head before you open the air handler.
You are faster.
More confident.
Better.
People notice.
The apprentice starts asking you questions.
And that’s when the next problem begins.
Now You’re Supposed to Know
This is the journeyman trap.
When you were an apprentice, nobody expected you to know everything.
Now?
You’re the guy.
You’re driving the truck.
You’re running the call.
The homeowner is staring at you.
The apprentice is standing behind you.
Dispatch wants to know how much longer you’re going to be there.
You’ve got $8,000 worth of tools sitting next to you.
There is absolutely no way in hell you’re about to tell everybody:
“I don’t know.”
So you stare at the gauges harder.
Maybe if you look really professional, the answer will reveal itself.
You open the electrical panel.
Take some readings you’ve already taken.
Walk outside.
Walk back inside.
Open your phone.
Close your phone.
Stare thoughtfully at the air handler.
This is an important diagnostic technique called:
Buying yourself some fucking time.
Every technician eventually becomes extremely proficient at it.
“It’s Probably the TXV.”
There it is again.
The most dangerous word in diagnostics:
Probably.
Probably isn’t necessarily bad.
A working diagnosis is part of troubleshooting.
But somewhere during the journeyman years, probably has a tendency to quietly disappear.
“It could be the TXV.”
becomes:
“It’s probably the TXV.”
which becomes:
“It’s the TXV.”
Did we prove that?
Well…
No.
But we’ve been standing here for an hour.
The homeowner keeps asking questions.
Dispatch has called twice.
The apprentice is watching.
And we’re beginning to feel like we should have an answer.
So now we don’t have a diagnosis.
We have a commitment.
And once a technician commits emotionally to a diagnosis, watch out.
Now Every Measurement Proves You’re Right
This is one of the most dangerous things we do.
We decide what’s wrong first.
Then we begin interpreting everything through that diagnosis.
Low suction?
TXV.
High superheat?
Definitely TXV.
Subcooling weird?
Oh yeah.
Textbook TXV.
The apprentice asks:
“Couldn’t low airflow cause some of this?”
No.
Shut up.
We’re doing HVAC.
😂
This is confirmation bias wearing work boots.
And every technician—including experienced ones—has done it.
The equipment is giving us information.
But we’ve stopped listening.
We’re trying to make the equipment agree with us.
Bad strategy.
Air conditioners are remarkably indifferent to our professional reputation.
Then the Apprentice Ruins Your Entire Afternoon
You’re an hour and fifteen minutes into the call.
You’ve taken pressures.
Temperatures.
Voltage.
Amperage.
Static.
You’ve consulted an app.
You’ve read technical literature.
You’ve developed a sophisticated theory involving the metering device, refrigerant distribution and possibly the alignment of several planets.
The apprentice has been standing behind you quietly.
Finally:
“Hey…is that wire supposed to be loose?”
You look.
Goddammit.
No.
No, it is not.
You reconnect it.
The system starts.
Everything operates normally.
Silence.
The apprentice looks at you.
You look at the apprentice.
This is an important moment in his development.
You have two options.
Option one:
Pretend you were already heading in that direction.
“Yep. That’s what I was getting to.”
You were not.
Option two:
“Good catch.”
Pick option two.
Every time.
Because he found it.
And because someday you’re going to need him to tell you what you missed.
Eventually You Learn How Much There Is to Know
This is where the journeyman starts becoming something else.
Because after enough years, the trade begins getting bigger instead of smaller.
When you were an apprentice, HVAC seemed simple because you knew twelve things.
Now you know thousands of things.
And somehow you feel like you know less.
Different manufacturers.
Different boards.
Different motors.
Different refrigerants.
Different control sequences.
Heat pumps.
Straight cool.
Gas furnaces.
Two-stage systems.
Variable-speed equipment.
Inverters.
Communicating systems.
Mini splits.
VRF.
Sensors.
Transducers.
Software.
Fault histories.
Dip switches.
Manufacturer-specific logic.
Then somebody releases another system with nine boards and a 214-page service manual.
Fantastic.
Can’t wait.
At some point, a horrifying realization arrives:
I’m never going to know all of this.
Correct.
Now we’re getting somewhere.
Stage Three: The Senior Tech
Twenty-five years in the trade.
Thousands upon thousands of service calls.
He’s seen things.
The apprentice thinks he’s a wizard.
The journeymen call him when they’re stuck.
The service manager gives him the weird ones.
Nobody calls him because he’s the fastest guy at changing a capacitor.
They call him because when something makes absolutely no sense:
Maybe Dave has seen this shit before.
So you bring Dave the problem.
You explain everything.
Pressures.
Temperatures.
Static.
Voltage.
Fault codes.
What you’ve already replaced.
What you’ve eliminated.
Dave listens.
Walks over to the equipment.
Looks at it.
Checks a few things.
Stands there quietly.
You’re waiting for wisdom.
This is the moment.
The master is about to speak.
Dave scratches his head.
“I don’t know.”
…
Excuse me?
No.
You misunderstand.
WE don’t know.
That’s why we called YOU.
You’re not allowed to not know.
That’s the entire arrangement.
“I Have No Fucking Idea.”
And here’s the weird part.
Dave isn’t embarrassed.
Not even slightly.
He doesn’t immediately invent a diagnosis.
He doesn’t start listing his credentials.
He doesn’t tell you about the similar system he fixed in 2009.
He doesn’t care whether the apprentice thinks he’s brilliant.
He simply says:
“I have no fucking idea. Let’s look at the sequence.”
And grabs the manual.
That’s when you realize:
This might be the most confident technician you’ve ever met.
The Senior Tech Reads the Manual
This confused you when you were younger.
You assumed really good technicians didn’t need manuals.
Then you started working with really good technicians.
They read them constantly.
Because the senior technician understands something the journeyman occasionally forgets:
The manufacturer knows more about this particular piece of equipment than you do.
Maybe the board logic changed.
Maybe that fault code has three conditions.
Maybe there’s a service bulletin.
Maybe this model uses a different sequence.
Maybe that sensor should read something completely different than the last manufacturer’s sensor.
The senior tech doesn’t care about looking smart.
He cares about being right.
Those are very different goals.
He’ll Call Tech Support Too
This is another funny one.
The apprentice thinks calling technical support means you don’t know what you’re doing.
The journeyman will spend two hours trying to avoid calling technical support because he doesn’t want some guy reading a script to tell him to check voltage.
The senior technician?
He’s already on the phone.
“Yeah, I’ve got model number XYZ, serial number whatever. Here’s what it’s doing. I’ve got 24 volts here, nothing here, sensor is reading this, board is showing this code. What am I missing?”
Notice the difference.
He doesn’t call somebody and say:
“It’s not working. What do I do?”
He has already done the work.
He’s gathered information.
He’s narrowed the problem.
Now he’s using another resource.
That’s not weakness.
That’s efficiency.
Here’s the Full Circle
When you’re an apprentice:
You don’t know that you don’t know.
The trade still looks small.
You’ve learned enough to become dangerous and not enough to understand why.
When you’re a journeyman:
You know that you don’t know—but you really don’t want anybody else to know that.
You’ve built competence.
You’ve built confidence.
Unfortunately, you’ve also built an ego.
And sometimes that ego becomes another thing you have to troubleshoot.
Then you become the senior technician.
And finally:
You know that you don’t know.
And you don’t give a shit who knows it.
That’s freedom.
Because “I Don’t Know” Isn’t the End
This is the lesson.
When you’re new, “I don’t know” sounds like failure.
You think a good technician always has the answer.
He doesn’t.
A good technician knows how to find the answer.
Those are completely different things.
The best technician isn’t necessarily the guy who identifies the problem fastest.
It’s the guy who can separate what he knows from what he assumes.
Who can say:
I proved this.
I haven’t proved that.
This measurement doesn’t make sense.
I need more information.
I need the manual.
I need another test.
I need another set of eyes.
I don’t know yet.
That’s diagnostics.
Don’t Bullshit the Homeowner
This may be the most important part.
The homeowner is staring at you.
They want to know what’s wrong.
You’ve been there an hour.
You still don’t know.
Say it.
Professionally.
“I’ve found something unusual, but I haven’t proven the cause yet. I don’t want to guess and sell you something you may not need. I need to keep testing.”
That’s a hell of a lot more professional than confidently condemning a $2,000 component because you felt uncomfortable admitting you weren’t sure.
We have an industry full of very expensive guesses.
Don’t add another one.
Don’t Bullshit the Apprentice Either
He knows more than you think.
He sees when you’re lost.
😂
You’re not fooling him by staring intensely at your gauges.
And there’s actually something incredibly valuable about letting him watch you struggle through a diagnosis.
Explain your thinking.
“This doesn’t make sense to me.”
“I expected this reading, but I’m getting this.”
“Let’s look at the diagram.”
“I’m not sure. Let’s call somebody.”
You’re teaching him something much more important than the eventual repair.
You’re teaching him what to do when the answer isn’t obvious.
Because that’s the actual job.
One Day You’re the Guy They Call
And then it happens.
Years later.
You’re the senior technician.
You don’t feel like one.
In your head, you’re still the journeyman occasionally wondering what the hell is happening.
But the new apprentice doesn’t know that.
To him:
You know everything.
He watches you diagnose systems.
He asks you questions.
He sees other technicians call you for help.
He assumes there will eventually be a point in his career when everything finally makes sense.
Then one afternoon you’re standing together in front of a system doing something absolutely ridiculous.
You’ve tested it.
You’ve checked the obvious stuff.
You’ve checked the weird stuff.
Nothing.
The apprentice is waiting.
You can feel him waiting.
He’s expecting the answer.
You remember being him.
You remember thinking the journeyman knew everything.
You remember becoming the journeyman and being terrified somebody might discover that you didn’t.
And now you’ve come all the way around.
You look at the apprentice.
Look at the equipment.
Shrug.
“I don’t know.”
His eyes get a little wider.
Then you smile.
“Let’s figure it out.”
It’s Okay Not to Know
Apprentice, you are going to spend your entire career learning.
Right now, you don’t even know how much you don’t know.
That’s okay.
Someday you’ll become a journeyman.
You’ll know a lot.
And there will probably be a period when you become a little too impressed with yourself.
That’s okay too.
HVAC will fix that.
It has an incredible ability to humble people.
Stay in it long enough, keep learning, keep reading, keep measuring, keep asking questions, and eventually something changes.
You stop being embarrassed by the limits of your knowledge.
You realize nobody knows everything.
Not your journeyman.
Not the senior technician.
Not the guy at the supply house.
Not the technical-support guy.
Not you.
And strangely, that’s when you become really good.
Because you stop trying to prove how much you know.
You just start trying to figure out what’s true.
The apprentice doesn’t know that he doesn’t know.
The journeyman knows he doesn’t know but would rather nobody find out.
The senior technician says:
“I don’t know.”
All the time.
Because after an entire career of learning, he finally understands:
Those aren’t the three words that make you a bad technician.
They’re often the three words that keep you from becoming one.
“I don’t know.”
Pause.
Grab the meter.
Open the manual.
Call somebody smarter than you.
“Let’s figure it out.”
And once again…
The circle is complete.