Being an HVAC technician involves a lot of very technical and precise work, particularly when it comes to AC installation. This is why a proper education and training is so important for a long and successful career in the industry.
Unfortunately, not all technicians get things right during AC installations. In fact, there are a few practices that HVAC technicians actually get wrong more often than not. Why is that? It could be many things from displacency to simply not receiving proper education.
So, why is it important to talk about the shortcomings of AC technicians? In such a precise field that so many people rely on for their important service, these shortcomings are unacceptable. For those that are considering pursuing a career as a certified HVAC technician it is just as important to know the wrong way as the right way.
As an HVAC professional, you want to strive to provide the best care and service to your customers that depend on you to stay safe and cool. Knowing where others in the industry fall short can help you know where you can avoid the same pitfalls and become a more successful AC technician.
Keep in mind these common mistakes that HVAC technicians make during AC installation. You’ll notice the biggest pattern that emerges from these improper installation missteps is that they each can have serious negative impacts on the performance, efficiency, and lifespan of the air conditioning unit.
70% of technicians don’t follow proper vacuum procedures
One of the most important things technicians ignore not following proper AC vacuum procedures during installation. Vacuuming is important because it helps remove any excess moisture left within the system. Over time, moisture build up can cause long term damage from poor performance, corrosion, and even freezing with the AC system. Never skip this important step in the post-installation process.
70% of technicians don’t adjust for proper air flow
Ensuring an air conditioner has been adjusted for proper air flow ensures that it can efficiently and easily keep in-home air cool and comfortable for the customer. Proper air flow lets air more easily reach all the nooks and crannies, ensuring no random hot spots. When not adjusted properly, the system has a harder time performing and has to put in extra effort to keep the home cool, which not only can shoot up a customer’s utility bill but also causes AC’s to burn out faster than they should.
70% of technicians don’t charge unit per manufacturer recommendations
Correctly charging your customer’s AC system will ensure there is proper refrigeration to pull out hot air and keep their home cool. However, despite the fact that most manufacturers provide step-by-step instructions and offer their best practice recommendations, this correctly charging units often gets overlooked. The result is either an undercharged unit that can’t keep up with the heat and overwork itself or an overcharged unit that is loud and draws far more energy than it needs to.
90% of air conditioning installations are incorrect
Since these three steps during AC installations are so important, it may not be surprising to hear that more installations are done incorrectly than not. But, for an industry that prides itself on hard workers and providing a necessary service to its customers, this is a number that simply cannot continue to last.
Here at the Training Center for Air Conditioning and Heating, we are attempting to lower the statistics through a comprehensive training and education program for the next generation of HVAC technicians. The course is designed to teach students the skills and techniques required for entry-level employment into the residential and light commercial heating ventilating and air conditioning so that they can not just install and repair heating and cooling systems, but do it the right way to better serve their customers and help make them a more successful professional.
Interested in enrolling in an upcoming class? Learn more about how to join here.
It’s very rare to find a home equipped with an air conditioning system that doesn’t also have a furnace. Even in the Houston area, where hot weather is the norm and people rarely turn on their heaters, you’ll still find yourself working on plenty of heaters during your HVAC career. Heating units are similar to air conditioners but require a slightly different focus to repair or maintain.
Heaters may not be the most commonly used home fixture in Houston, but they’re still important for homeowners’ comfort and for your experience. Are you ready to help Houston families stay comfortable during the cooler season this year? Keep reading to refresh your memory.
How Do Electric Heaters Work?
At its core, an electric heat furnace functions similarly to a floor space heater that plugs into the wall. A space heater consists of a heating element and a fan to blow the hot air into the room. If you increase the size of both the fan and the heating element and add an evaporator coil, you have an electric heat furnace. Due to its simple design, an electric heat furnace rarely fails and is easy to diagnose and repair when it does have problems.
Electric heaters, of course, require electricity to power the massive heating element–at least 240 volts, in fact, though the exact motor power you need depends on the size of the house. (The fan uses power too, but not nearly as much.) Look for 1-2 large wires coming from the breaker box powering this heater. A transformer inside the heater converts the power to 24 volts, which is then diverted to the thermostat that determines whether or not the heater turns on. When the thermostat is triggered, it sends those 24 volts of power from the red wire up a white wire back to the furnace. The power then snaps the relays, allowing the heat strips and fan to power on and start blowing warm air into the home.
Remember, the strips in an electric heating element heat up very quickly. The fan isn’t just essential to warming up the house. The breeze it generates also cools the strips down just enough to keep the entire system at a safe temperature. Imagine what could happen if the heater came on but the fan stopped working, allowing the strips to overheat!
Pro Tip: When installing a thermostat and electric heater, program the thermostat specifically for electric heat. The transfer of power is different depending on whether the heater is powered by gas or electricity.
Maintaining Electric Heat Furnaces
Maintenance of an electric heater tends to consist of two primary tasks. First, check the AC coil regularly and keep it clean so air can flow unrestricted. Second, check the wiring connections and tighten any that seem too loose. Wires that carry high amounts of electricity naturally loosen over time, creating a significant fire hazard. When in doubt about whether or not a particular wire is safe, don’t hesitate to call an electrician.
Additionally, check the manual for any recommendations or cautions from the manufacturer. Too many HVAC technicians forget the wealth of information that their manuals hold. Take advantage of this handy guide!
Electric furnaces are 100% efficient, meaning that the homeowner gets heat from every bit of electricity they pay for. The only potential drawback to this is the cost of the electricity used to power the furnace. Depending on how cold the house gets and how often the furnace is used, this cost can add up quickly. Gas heating is generally cheaper even when you factor in its less than 100% efficiency rating. Not every homeowner can choose gas–the builder may have opted for electrical wiring as the cheaper initial option–but if your clients ask for a recommendation, gas heating is generally a better choice for them.
To summarize, the pros of an electric heater are as follows:
- Cheap, easy installation
- Cheap upfront cost for you and your client
- No roof penetration necessary
The largest drawback of an electrical heater is simply the cost of the electricity used to power it.
Understanding Electric Heat Furnaces
In your HVAC career, you’ll be faced with a variety of challenges in a variety of settings. Differing machinery or systems are only the tip of the iceberg. By educating yourself on how a well-run system should function and understanding its pros and cons, you can provide better services to your clients and gain more business in the future.
Join the conversation to learn more about HVAC repairs and maintenance.
Home AC units use motors to move the air and motors to move the refrigerant. Whether due to overheating, a lack of proper maintenance, or old age, HVAC motors can break down and cause the entire system to come to a halt. That’s where you as the technician come in! How much do you know about diagnosing and repairing damaged AC motors?
Common Air Conditioning Motors
Every home is different. In your HVAC career, you’re likely to encounter AC systems ranging from the very old to the factory new. Consequently, you need to understand the different types of motors you’ll encounter and how to properly handle and replace each one as needed. Take some time to familiarize yourself with the 5 motors you’re most likely to encounter:
- Condenser fan motor
- Blower motor
- ECM motor
- Combustion fan motors
- Compressor motors
1) Condenser Fan Motor
Since a condenser fan motor will get rained on and be exposed to the elements, it’s rated for use outdoors sealed up on the ends and sides to keep water out. These motors are usually one speed and come in horsepower ranges from 1/6 hp to 1/3 hp. They always have a capacitor, usually a dual capacitor if it’s an original motor and a single capacitor if it’s a replacement aftermarket motor. The factory motor usually has three wires and the aftermarket version usually has 4 wires.
The main thing to remember on a condenser fan motor is the main service issue is usually a bad capacitor. This issue generally surfaces during summer, when the weather is hottest. If the motor is bad, measure the fan blade height to the finger guard before you ever remove it. The placement of the blade is absolutely paramount to the operation of the condenser, even more so than its original placement on the motor shaft. Consequently, you should always keep any replacement fan blades at the exact same height, since getting this blade height wrong by even an inch can mean the compressor will overheat and burn out. If you need to replace the condenser fan motor and capacitor, take note of these key pieces of information first:
- Frame size
Above all, never try to force the replacement blade onto the motor. After all, a motor is easy to replace while the correct fan blade might take you weeks to find.
Finally, don’t fall back on the assumption that you can simply substitute a different pitch blade when necessary. The wrong size or type will not work and may overheat the fan motor or simply not move enough air, meaning that the AC unit won’t do its job. Airflow at the condenser is critical.
2) Blower Motor
Another popular air moving AC unit motor is the blower motor. The blower motor looks similar to the condenser fan motor, except the blower is ventilated on the sides and/or the ends to allow air to pass through. Blower motors also have a capacitor, in addition to way more wires than condenser fan motors.
The main cause for blower motors failing is that dirty air passed over them and stopped up the vent hole, causing the motor to overheat. This indicates a deeper problem since the air filter should catch dirt before it reaches the motor. Sometimes a blower motor experiences a capacitor failure, causing it to turn backward. They look normal running this way but move almost no air. After a couple of hours, the evaporator coil freezes and the house overheats, prompting the homeowner to call for help.
To replace a bad blower motor, remove the blower housing with the motor and blower. You have to remove the curved plate first, but this is where the wheel slides out of the housing. Make sure to reattach the blower wheel securely when you’re done to avoid burning out your new motor. Finally, remember that blower motors also have universal replacements. Just remember that electric heat furnaces us 230-volt blower motors (in contrast, gas furnaces use 115-volt motors) and you’re good to go!
3) ECM Motor
The ECM motor is a blower motor with an electronic control module mounted on the end. These motors are special; some must be set up at the supply house with special programming. Others have program modules you can buy to do it yourself. A few particularly advanced models even allow you to program the unit from your phone!
ECM motors can cost up to $1000, so be sure to get current pricing before you give your client a quote. Beginning HVAC technicians may benefit from getting an expert technician’s input on how to handle ECM motor repairs since, considering their high price tag and complicated inner workings, trial and error is not the way to go with ECM motors. When you’re dealing with equipment this expensive and advanced, it’s better to be safe than sorry.
Pro Tip: If you get stuck on an HVAC job and can’t get hold of an expert, call the AC motor’s service number to talk to a brand representative. They’re usually willing to help you out.
4) Combustion Fan Motors
Combustion fan motors are found in gas furnaces. These types of motors don’t have a capacitor, just two wires. It’s very easy to diagnose what’s wrong with a combustion fan motor. If the motor is receiving its full 115 volts but not running, it’s burned out and the whole thing likely needs to be replaced. You can usually buy replacement units from factory brand reps.
Since these motors tend to last as long as the gas furnace they’re installed on, you likely won’t see too many combustion fan motor failures. But even when you do, the replacement won’t take you very long and will be a pretty straightforward process.
5) Compressor Motors
The most expensive and hardest to replace of the air conditioning motors is the compressor. This motor is sealed inside the compressor housing, so you can’t determine visually if the motor has failed. The only parts you can test are the three terminals sticking out of it.
Compressor motors are really two motors in one: the start motor and the run motor. They just happen to be connected together at the common wire terminal. The start windings are very small wires that are wound on the motor to deliver a quick burst of power and start the motor. Since the start windings are only designed for the initial spark. if the start windings have to work for more than about three seconds, they’re likely to burn out. The motor’s run capacitor ensures the start windings don’t work too hard and keeps the entire motor running correctly.
While this is an expensive part to misdiagnose (a new compressor can cost up to $1000 wholesale), don’t panic. It’s difficult to correctly diagnose a motor you can’t see, so the majority of problems with compressor motors come from misdiagnosis rather than equipment failure. Using a meter, test each of the three terminal connections to see if they display the proper resistance sums and have any charge to ground. If there is any reading to the ground, the motor is bad.
Be sure to always remove the power and discharge any capacitors in the unit. The compressor might not read anything when you test it–this is when 90% are incorrectly condemned. The truth is that compressors have an internal safety switch that turns the motor off when it overheats, and if you test the motor while the switch is activated, it’s easy to assume the motor has burned out. With this information in mind, never rush to the assumption that the compressor is burned out. Compressors should last the life of the unit. Before you try to replace the motor, try to determine the cause of failure or see if the safety switch eventually deactivates.
AC Motor Replacement & Repair
Knowing the normals of each common type of HVAC motor is a critical first step in developing your long-term HVAC career. Take the time to familiarize yourself with the most common types of motors and learn how to repair or replace each as necessary. As you build your understanding of air conditioner systems and maintenance, you’ll become better at your job as a technician.
Connect with us to learn more about our HVAC classes and register for our January 2020 term.
Are digital gauges necessary? This is a question that comes up a lot, and there are a wide variety of opinions. After all, the HVAC industry doesn’t seem to favor one style over the other. Why is one any better than its alternative?
Most HVAC technicians should keep at least two sets of gauges, and potentially three depending on their exact work. Different types of HVAC units may be more compatible with different gauges. Consequently, there isn’t really a clear answer to the question of which gauge type is superior, if at all. Let’s take a closer look at both types and their potential applications to find the right answer for your situation.
Different Types for Different Work
You need two, possibly three, sets of gauges depending on what you are doing. Some techs like to have one set for 410 refrigerant machines and another for R22 machines. However, we have so many different types of refrigerants now it’s not practical to have a set of gauges for each. One set of digital gauges and one back up set of analog gauges is all most people will ever need.
Using Digital vs. Analog Gauges
Digital gauges are far superior for testing and adjusting the charge, and they’re absolutely imperative if you want accurate superheat and subcooling readings. Digital gauges have temperature clamps that connect to the liquid line and suction line and have built-in pressure-temperature charts. You simply tell the gauge set what refrigerant you are testing, hook up the hoses and temp clamps, and get live instant readings of superheat and subcooling. The margin of error is remarkably low.
If you use analog gauges to perform critical charging, you will have to read literally between the lines of the needle and the gauge lines. Once you guess the pressure reading, you must then use a pt chart to obtain the temperature equivalent. After you get that number, you have to actually take a temp reading of the appropriate line and subtract those two numbers. Along the way, chances are you will either misread something, make a mistake in the math, make a pt chart conversion mistake, or several of the above. Even if you manage to get all that correct, there’s a good chance that the system pressure or temperature changed between all the readings. This change alone will lead to inaccuracies of four to five degrees. When you are talking about subcooling number targets of 10 or 12 degrees and you miss it by six, that’s a significant margin of error.
What Do Industry Professionals Prefer?
Some brand manufacturers require the dealers to charge with digital gauges if they want to continue and sell that brand. Usually, these policies exist because manufacturers have received warranty returns due to improper charging methods rather than actual problems. Consequently, the requirement for digital gauges is a (generally successful) attempt to combat these warranty returns and preserve business.
Analog gauges have their place, however, especially if you are working on a system that has a bad burn out and has turned the oil into acid. You will not want to pull this into your $400 digital gauge set, so you whip out the trusty analog set. The analog is also a great back-up set when your digital set goes out.
Pro Tip: Different brands of digital gauges may have varying features, but overall, they all work about the same. Just find the brand with features you like the most.
Neither is Always Better
To summarize, there is no way to state for certain which type of gauge is better. While digital gauges are more convenient and generally preferred by HVAC professionals and manufacturers, sometimes an old-fashioned analog gauge works just as well or even better. The ultimate deciding factor is preference. To make sure you always have the type you or a client prefer, maintain a set of each type of gauge just in case.
Join the conversation to learn more about the best HVAC equipment for your situation and preferences.