When Should a Technician Recommend a Leak Search on my HVAC System?

how does an hvac unit work

Every spring and early summer we get what’s called the “first wave” of worried homeowners and rental tenants who realize there is something 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. This week we’re going to talk about refrigerant leaks, what the laws are and moral obligations you and your technician 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 in the hot Sacramento valley, I go out on these calls all time. Sometimes customers will call into the office and tell us another company told them they have to get a new system because they’re not allowed to fix older systems anymore. Other excuses I hear is, they don’t make R-22 anymore so there is no refrigerant to add back into their system. Unsuspecting homeowners will believe these technicians and fall for their unethical tactics. Other homeowners will call Fox Family Heating, Air Conditioning and Solar where we will offer a free second opinion to come out and 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 our usage and consumption of refrigerant in this country. In other parts of the world, not so much! It’s crazy to think of the irresponsibility technicians in other parts of the world have when it comes to just pouring pounds and pounds of damaging refrigerant to earth’s ozone layer. You see, the refrigerant in our older systems now is R-22, a mix of chemicals that contains chlorine which degrades the ozone layer quickly if it were to get out into the open. The systems in our homes hold anywhere from 3 to 20 lbs. of refrigerant. Just two lbs. of refrigerant leaking into the atmosphere causes as much environmental damage as a van driving 10,000 miles down the road. The damaging result is global warming and accelerated environmental weather extremes.

You know the stories. You’ve seen it on TV. Al Gore told you this crazy weather is because of an accumulation of damaging practices we have as humans to this giant world. Refrigerant loss from our 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 right now, just says if the system holds over 50 lbs 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 that leak is taken care of bi-annually 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.

how does an hvac unit work
When I get out on these calls with low refrigerant suspected, I will attach my gauges to the air conditioner outside and fire it up. The system will start but doesn’t sound normal. A light clanking noise quickly repeating itself in its own rhythm. After a few minutes of running, the gauges show me there is indeed very little refrigerant left in the system.

What does this mean? 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 out at your house.

During the call, and at the very least, a technician should volunteer to visually go around and check all the brazed points in your lines. There are at least two points at the evaporator coil and two at the outdoor condenser coil that the installing technicians brazed together to complete your HVAC system’s 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 evaporator coil are up in the attic, the technician needs to get their ladder out and go up there to do this visual check. While they are up there, they should check the P-trap for oil in the condensate lines. A good technician knows that the majority of leaks happen at the evaporator coil or the condenser coil and very rarely at the line set that runs in between the two. If the evaporator coil is leaking badly enough, oil will drop down into the evaporator coil drain pan that the water usually goes down into. It then starts its way down the condensate drain line until the oil fills up in the P-trap. These are very easy checks the technician should include on the original diagnosis charge.

If they don’t see anything there and are sure they have checked all the easier points of access to the refrigerant lines at the evaporator coil, the tech should check the outdoor coil looking inside the top off the unit and all around it looking for darker stains of oil. Also, are the schrader cores where the gauges attach too loose or not sitting correctly within the service valve? If the tech is satisfied the leaks are not there, then he/she should start an investigation of sorts.

“Is there a history of leaking with this system?” is a question the technician should ask. The homeowner has some obligation to tell the truth here. If the owner deceives the tech, then we’re really not getting anywhere are we? I can say there have been very few owners that I didn’t believe when they told me, “No, never any leaks before,” or “Well we just moved in here two months ago.” At this point RIGHT HERE 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 at Fox Family 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 want to know if there has been refrigerant added to this system before, and if so, when?

The main reason why I wrote this blog. 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 this system is leaking and if so, how much and how often?

If the refrigerant was admittedly, “topped-off” last year, then I think it is a good time to introduce the idea of looking for the leak. This is mentioned whole heartedly in the best interest of the planet and its survival. We want to avoid being unethical here now that we know the system is being topped off every so often to maintain it’s cool air. R-22 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.

When I want to introduce the leak search, I tell my customer, let’s get you back cooling today so your family is comfortable. The we should go ahead and start the leak search process which includes us going to the different parts of the AC system with our electronic sniffer looking for the leak. The majority of the time I 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 a fluorescent dye to the system so we can let it circulate in the system for a couple of weeks (while you are still 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. We’ll take the dye kit which comes with some 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 plainly see the leak is coming from there. We shouldn’t stop looking though! Just because there is one leak doesn’t mean there aren’t two or more holes.

If the leak is in the fins of the evaporator or condenser coil, we can’t get in there to fix the leak without compromising the standards of the manufacturer. It’s possible yes but, the possibility of the repair causing a restriction or other repair if the brazing compound didn’t settle properly on the under side 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. This means when the leak is in the evaporator or condenser coil, and it’s not on a u-bend 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 toward the cost of repair. Some of these repairs can be upwards of $2000 to replace parts, so it’s nice to know we can find the leak, and then put that money towards the cost of repair.

Our clients always appreciate knowing exactly what to expect during the leak search process. Simply explaining the repair in common terms that aren’t too “techie” for the customer are also appreciated. A leak search is not always needed just because you went out to a house for the first time and it has a leak. There is proper way of establishing knowledge and data about this particular unit. Starting at that first time out there and getting the customer cool is the most important thing. Next year if we have to add refrigerant again, then we should establish a plan for finding the leak. It’s our moral obligation as techs and as homeowners to find the leak and repair it. If there is a history of leaking refrigerant from your system, it’s on you as homeowners to let us know. I realize it’s going to cost some money to make the repair, but once it’s fixed, you won’t have to keep paying for refrigerant that just keeps getting more and more expensive every year.

Thanks for checking out this blog on leak search recommendations. If you are a homeowner and are concerned that what the other technician said doesn’t match I’m saying here, you might want to call a trusted HVAC company that will set you straight and actually give you options other than “You need to replace your system!”

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