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How to Leak Search the AC System

How to Leak Search the AC System

Every spring and early summer, we get what’s called the first wave of the worried homeowner and rental tenants who realize something’s wrong with their AC system. Sometimes it’s a mechanical part like a capacitor or a motor but other times it’s a refrigerant issue.
We’re going to cover refrigerant leaks, what the laws are, and the moral obligations you and your technicians may have when it comes to refilling your HVAC system with refrigerant year after year.
As a technician who goes to hundreds of homes every summer, sometimes customers will call into the office and tell us that other companies told them they have to get a whole new system because they’re not allowed to fix older systems anymore.
Other excuses we hear is they don’t make R22 anymore so there’s no refrigerant to add back into their system.

Unsuspecting homeowners will believe these technicians and fall for the unethical tactics. Other homeowners will call Red Deer Heating and Air Conditioning where we will offer a free second opinion to come out to verify a leak that supposedly exists and give them proper solutions to remedy the leaky system.
Let’s talk about the obligations we as decent human beings have to this great planet we live on.
The government regulates and monitors what is used in the consumption of refrigerant in this country. In other parts of the world, not so much.
It’s crazy to think of the irresponsibility, technicians and other parts of the world have when it comes to just pouring pounds and pounds of damaging refrigerant into the earth’s ozone layer.

The refrigerant in our older systems now is R22 which is a mix of chemicals that contains chlorine that degrades the ozone layer quickly if it were to get out into that open. The systems in our homes hold anywhere from three to twenty pounds of refrigerant.
Just two pounds of refrigerant leaking into the atmosphere causes as much environmental damage as a van driving 10,000 miles down the road.
Refrigerant laws for your home HVAC systems don’t even have a definite requirement yet as to when we have to perform a repair on the leak.
The government says that if the system holds over 50 pounds of refrigerant then we have to fix the leak. Not only do we have to fix the leak on those systems but we have to come back and verify the leak is taken care of on a biannual basis until the EPA requirements for follow up are satisfied.
We as technicians are now responsible for logging any refrigerant coming in and out of any given system, not just commercial and industrial machines but residential too.
When we get out on these calls with low refrigerant suspected, we’ll attach our gauges to the air conditioner outside and fire it up and let’s say the system will start but doesn’t sound normal, maybe like a light clanking noise quickly repeating itself in its little rhythm.
After a few minutes of running, the gauges show us that there is indeed very little refrigerant left in the system. What does this mean?

Pressure Gauge

The HVAC system is separated into three lines for your refrigerant to stay in – the evaporator coil at your furnace, the condenser coil on the outside unit, and the copper line set that runs between the two coils.
When the system was installed, these three sections were brazed together by the technician at your house. During the call and at the very least, a technician should volunteer to visually go around and check all the braze points in your lines.
There are at least two points in the evaporator coil and two others at the condenser coil that the installing technicians braze together to complete your HVAC systems refrigerant lines. The technician should be looking for oil around these connections.
Why? Because the refrigerant in the system carries oil with it to lubricate the components inside the system like the compressor. This means if the furnace and the evaporator coil are up in the attic, the technician does need to get their ladder out, go up there, and do an actual visual check. Or if in the basement – go there and check it out.
While they’re up or in the basement there they should check the p-trap for oil in the condensate lines. A good technician knows a majority of leaks happen at the evaporator coil or the condenser coil and they very rarely happen at the line set that runs in between the two.
If the evaporator coil is leaking badly enough, the oil will drop down into the evaporator coil drain pan, that the water usually goes down into it, it’ll then start its way down the condensate drain line until oil starts filling up in the p-trap.
These are very easy checks the technician should include on the original diagnosis charge for coming out. If they don’t see anything there and they’re sure they have checked all of the easier points of access to the refrigerant lines at the evaporator coil, the techs should then check the outdoor coil looking inside the top of the unit and all around it looking for darker stains of oil.
Also, the Schrader cores where the cage is attached to, sometimes are too loose or they’re not sitting correctly within the valve. If the tech is satisfied that the leaks are not there then he or she should start an investigation of sorts.
Is there any history of leaking with this system is a question the technician should ask. The homeowner has an obligation, to tell the truth here. If the owner deceives the technician then we’re really not getting anywhere are we.
We can say there have been very few owners that we didn’t believe when they told us “No, never had any leaks before” or “Well, we just moved in here a couple of months ago.” At this point, a technician should offer a strategy to the homeowner to help determine if it’s a leak and if so, what will we do to try to find the hole and repair the system so it doesn’t leak anymore.
Our technicians ask if there is a history of leaking for this HVAC system because it helps us establish a base point for the rate in which this system is leaking. We just want to know if there has been refrigerant added to this system before and if so, when?
If this is the first time the system has been topped off to get you cooling again then we should get you cooling and use this as a starting point to determine if the system is leaking. And if so, how much and how often?
If the refrigerant was admittedly topped off last year then we think it is a good time to go ahead and introduce the idea of looking for the leak. This is mentioned wholeheartedly in the best interest of the planet in its survival. We want to avoid being unethical here now so now that we know the system is being topped off every so often to maintain its cool air.
R22 has chlorine and R410 still has massive global warming potential. We need to stop that from getting out to the ozone. If we can find the leak then we can get the system back to factory specs. What we want to introduce the leak search, we tell the customer “Hey, let’s get you back cooling today so your family is comfortable.”
Then we should go ahead and start the leak search process which includes us going to different parts of the AC system with our electronic sniffer looking for the leak. The majority of the time we can find the leak with this method that cost X amount and is good for the first hour of searching for the leak.
If we can’t find the leak after the first hour, we bump it up a level to X amount. This level of leak search includes us adding fluorescent dye to the system so we can let it circulate in the system for a couple of weeks all while you’re staying cool.
Then we come back out and look for the dye.
If there is indeed a hole somewhere in that copper or aluminum line, the oil and the dye inside the lines will spew out of the hole and splash onto anything around it.
Like the aluminum fins on the coil or the condensate drain pan and into the p-trap will take the dye kit which comes with some fancy yellow glasses and a UV flashlight, when we shine the light onto the dye which has come out of the leak and we have our yellow glasses on we can see that the leak is coming from there.
A technician shouldn’t stop looking though. Just because there’s one leak doesn’t mean there aren’t two or three more holes. If the leak is in the fins of the evaporator coil or condenser coil, we can’t get in there to fix the leak without compromising the standards of the manufacturer.
It’s possible but the possibility of that repair causing a restriction or other repair – if the brazing compound didn’t settle properly on the underside of the repair spot, also the copper or aluminum is a lot thinner on the coils than the copper line set that runs in between.
The reason it is so much thinner is because of heat transfer that happens at the coils so they need that copper to be thinner. This means when the leak is in the evaporator or the condenser coil and it’s not on a U-pin or other easily accessible spot, we’ll recommend you getting another coil from the manufacturer.
We’ll get it ordered and replaced for you in no time. No matter where the leak is, the money you have paid for the leak search will go towards the cost of the repair. Some of these repairs can be upwards to $2000 to replace the parts so it’s nice to know we can find the leak and then we can put that money towards the cost of the repair.
As a customer, it’s nice to know what to expect during the leak search process. Simply explaining the repair in common terms that aren’t too techie for the customer would be appreciated. A leak search is not always needed just because you went out to the house for the first time and filled up some refrigerant.
There is a proper way of establishing knowledge and data about this particular unit. Starting up for the first time out there and getting the customer cool is the most important thing. Next year if we had to add refrigerant again then we should establish a plan for finding that leak.
It’s our moral obligation as techs and as homeowners to find the leak and repair it. If there’s a history of leaking refrigerant from your system, it’s on you as homeowners to let us know.
We realize it’s going to cost some money to repair but once it’s fixed you won’t have to keep paying for the refrigerant that just keeps getting more and more expensive every year.
If you’re a homeowner and are concerned that what the other technician said doesn’t match what we’re saying here, you might want to call a trusted HVAC company in your area that will set you straight and give you some options rather than say, “You need a new system.”
Give us a call at Red Deer Heating and AC and we’ll fix your AC system right!

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