As a technician starting out in this field, I was told by the company trainer to hook
the hoses to my manifold gauges up every time I’m out on an AC call.
Much like a doctor who wears a stethoscope around his neck, hooking my gauges up meant
we were the professionals; And when I bring the customer out to the AC to discuss recommendations
or repairs, they would see I was the one with all the knowledge.
Was my trainer on to something, or was this just another effort to blow smoke up the customers
rear and make him fall for that company’s high-pressure antics?
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Every residential air conditioner has a service valve that technicians hook their gauges up
to in order to read the pressures of the refrigerant inside the system.
Those service valves have a Schrader core (That’s Schrader Core) that gets depressed
when the technician’s manifold hoses attach to the service valve.
It’s just like a valve stem on your bicycle tire.
When the core gets pressed in, the refrigerant is allowed into the technician’s manifold
so the pressure can be read on the gauges; And it takes an experienced technician to
interpret those readings to accurately determine what is going on with the refrigerant pressures
in the system.
I’m not gonna get get to far into it, but we can see the temperature of the evaporator
coil, the condenser coil, as well as determine the superheat and subcooling levels for that
system.
But do technicians need to hook up every time they go out on a preventive maintenance or
a service call?
Does it mean we didn’t give a full comprehensive diagnostic if we don’t?
No!
Most technicians will walk up to a system and assess how the system is running by doing
a couple things.
First, have you asked the customer how their system is running?
If not, that’s valuable information to get.
If the system has been running great according to the customer, there may not be any reason
to hook up the gauges.
So, you’ve asked the customer how the system has been performing, and they said the system
has been running fine.
They just wanted to call you out for a pre-season tune-up, like the ones we offer at Fox Family
for just $75.
Have you checked the temperature split to see if the system is blowing nice cold air?
That would be more input that should sway a technician from hooking up their gauges.
I know it’s a little cliché but checking the temperature of the suction line can further
indicate that you wouldn’t need to hook up your gauges to the AC system.
The liquid line should be a few degrees warmer than the outside temperature, too.
So, making some initial checks like this can make someone comfortable about not hooking
up their gauges to the system.
Why don’t I think you should hook up your gauges so much?
Hooking up your gauges can do several things to actually harm the performance of the system
over the long run.
Maybe not today, but the overall lifespan of the system can be affected.
I feel like hooking up gauges from one system to the next contaminates the next system you
hook up to.
Taking a little bit of refrigerant from one system, going to the other side of town and
putting your gauges on that system has now introduced a small amount of contaminants
that system has never seen before.
Moisture and air from one system can easily be transferred to another system.
This is definitely true if your no loss fittings or ball valve fittings on your hoses retain
the R22 freon in one system and then get hooked up to that one on the other side of town that
is an R410a system.
A technician doing this will literally create a new mixture, a new refrigerant even, where
if done enough times will throw the readings off on a system so badly, not even the most
experienced techs will be able to tell the true pressures inside that system.
This will eventually create a situation where a technician down the road will tell the customer
they need to remove all the refrigerant and start over with a new manufacturer’s charge
of virgin refrigerant to determine if anything else is wrong with the system.
Another reason to avoid putting your gauges on ever time you go out on a call is to reduce
the chances of exposing yourself to refrigerant burns.
In the unlikely event that you find a burr in the threading of the service valve and
get it stuck it could create a situation where the refrigerant starts shooting out of the
hoses.
Some techs ill persist in trying to get the hose off and burn themselves in the meantime.
I know it’s a small chance but tell that to the techs who have ended up with huge blisters
on their hands trying to play hero, losing time off work, further impacting their paychecks
and livelihood.
My last point I want to make in persuading you to think twice about hooking up your gauges
to every AC system you come upon, is the fact that the Schrader core we spoke of earlier
can be loosened creating a tiny leak.
The Schrader core is threaded into the service valve.
And while you’re screwing the new core into the valve which way are you tightening it?
Righty tighty.
Lefty loosey.
Taking off your hoses in the normal counterclockwise direction mimics the same direction it takes
to unscrew the Schrader core.
I’ve seen it a few ties already this year, when I went out on a service call for no cooling.
The client said the system only blows room temperature air.
They also said they have been having maintenance done by a local company every spring and fall.
There was no temp split from the registers, and the suction line at the AC was warm to
the touch.
I unscrewed the service valve cap to attach my hoses.
And when I got the cap off, I saw a small amount of liquid refrigerant spewing out of
where the valve core sits.
I think I’ve found the problem.
To put it another way, ACHR News had a story recently saying, “There is no reason to
ever put gauges on an air conditioning or refrigeration system after the initial installation
unless a problem with the mechanical refrigeration circuit is suspected.”
They went on to say using a psychrometric chart, digital thermometer, digital humidity
stick, and an accurate method to calculate airflow can replace having to apply your manifold
gauges anytime.
Remember, only virgin refrigerant is supposed to be in these systems.
So, the less we go from system to system putting on and taking of our refrigerant hoses will
not only save time, but it will increase equipment life, maintain performance, and reduce refrigerant
emissions to the atmosphere.
Like I said at the beginning, I was told by the company trainer to hook up my manifold
gauges up every time I’m out on an AC call.
He said it would make me look like the doctor who wears a stethoscope around his neck.
He said my customer expects to see those hoses hooked up, and if they weren’t, they might
think something wasn’t right.
I just think he wasn’t worried about the integrity of the customer’s AC system or
the integrity of his company’s high-pressure sales antics.
As always, I appreciate you all for watching our videos here at Fox Family in Sacramento.
I would love to hear your comments as a technician out in the field about how your company practices
service calls and maintenances regarding hooking up your gauges every time you get called out.
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right, and if you click that little bell next to it, you’ll be notified of all our videos
as they come out.
Thanks so much for watching and we’ll see you on the next video!