Central air conditioning system not working? Well depending on what type of system that you have there could be a hundred reasons that your air conditioning is not blowing cold air. [click to continue…]
How about some Hvac Training for homeowners? Simple questions pop up in my stats every day and I feel that the searchers aren’t getting their questions answered completely. So I have compiled a list of questions that people have searched for and found my page with, specifically homeowners. On top of that I have also added some of the most frequent asked questions that I get from customers.
Let’s face it, homeowners that aren’t educated about their Hvac system make us service technicians money. When homeowners neglect getting preventative maintenance done on their system and neglect other things like monthly filter changes, it can damage the air conditioning and heating equipment. So let’s answer some questions and get some Hvac training for the homeowner who wants to keep their unit up to par.
How often should I change my air filter?
I tell all my customers that it depends on the living conditions. If the home is occupied year round you are going to want to check the air filter once a month. If you are a seasonal resident the home may be able to go 3-6 months without being replaced. Bottom line is the more people, and the more often a home is occupied, the faster the air filter gets dirty, that’s just how it is.
If you have pets such as cats and dogs, your air filter is going to get dirty faster. If you carpet, its going to get dirtier faster. So depending on your living conditions, and what type of air filter your have in your hvac system, will determine how often you should change it.
For instance 4 inch wide Merv 10-16 filters may last you 6-12 months, even if the household is occupied full time. You are going to have to determine when it’s time to change your filter. If you buy the cheap fiber spun filters, you may need to change them monthly. Basically if you put a brand new filter up to the one that’s in your system, and the old one looks discolored, its time for a new filter, if you hold the old filter up to a light and can’t see through it, its way past due and internal damage may have already been done to your compressor.
What’s the lowest temperature I can set my thermostat?
Don’t go lower than 72 degrees, period. Also, don’t set your thermostat lower than the outside ambient temperature in cooler months. Air conditioners are made to dehumidify the home, not turn it into an ice box. If you want your home freezing cold the get a commercial refrigeration system – kidding.
When you set that thermostat below 72 degrees Fahrenheit, your evaporator coil starts to get very very cold. On super hot days you may get away with this, but you can actually get that evaporator coil so cold the refrigerant may still be in liquid form when returning to the compressor, which will eventually kill your compressor if you are one of those homeowners that love setting their thermostat to cold temperatures.
Why is my air conditioning freezing up?
Lack of air flow such as clogged a/c filter. Undercharged with refrigerant. Bad expansion valve. Indoor blower motor bad or defective. Setting your thermostat too low, especially when it’s below 80 degrees outside. I covered this topic right here….
What does the a/c drain line look like?
Air conditioning drain lines on central cooling units are located at the air handler. In residential homes they are commonly made of pvc or even cpvc. If your air handler is located in the attic it may and should have armaflex over it, this is to prevent the pvc from sweating and potentially causing water damage.
Condensate drain lines get clogged, so in order to unclog a condensate drain line, you must be able to locate and identify the condensate drain line on both the inside and outside (if applicable). Keeping your drain line clean is part of preventative maintenance and can save your money on service calls and possible flooding and water damage. You can learn more about keeping your condensation line clean here.
How Can I Tell if My Unit is Cooling?
The very first thing I do when I walk into a customers home to perform preventative maintenance, is I look at the thermostat and note if it’s achieved the set point for cooling. For instance if the thermostat has been set at 74* all day, and its 95* outside, and your thermostat doesn’t ever reach set temperature of 74*, and hangs around 77 or more, then your unit is not cooling properly.
Another way that a homeowner can test if their residential air conditioning unit is cooling is to take a Delta T, or as I call it a TD, temperature difference, temperature drop. This is where you get a thermometer and measure the indoor air temperature right before the evaporator coil, and right after the blower motor. Basically if you have a horizontal air handler, stick the thermometer in the duct work before the air handler and then after the air handler. Record the temperatures and then subtract your supply air temperature from your return air temperature. This is your TD, or delta T.
If you have a R-22 system you are looking for a 17-21 degree temperature difference, for 410a residential systems you are looking for 16-18 degree temperature difference. Remember though, these are just ball park numbers, it will get you close but not perfect, and as humidity changes so will your TD. There are more accurate ways of measuring temperature difference by using your return wetbulb and drybulb temp to calculate your Target Exit Evap Temp, but this requires more than a simple thermometer and temperature charts.
One last way the homeowner can get a ball park idea if their air conditioning unit is cooling or not is to feel the temperature of the air being discharged from the outside fan motor. On residential units, your should feel hot air being discharged from the top of the fan motor. If you are in heat pump mode or have a pool heater, you should feel very cold air being discharged from the top of the fan motor. If you feel air being discharged from the condensing coils, and sucking in from the top of the fan, then it’s probably running backwards.
Home owners please submit your Hvac questions in a comment and I will do my best to answer them. Be aware that Hvac is a very technical trade and service technicians are properly trained through schooling and experience to troubleshoot problems, so DIY questions may not be answered.
The salary of an Hvac service technician will vary depending on many factors, such as which region you are working in, whether or not you get commission, how much experience you have, and how many hours you are willing to work. Since you are probably here because you are thinking about attending a Hvac school and making a career out of it, you are going to start at the bottom of the ladder, no matter how much you paid for hands on hvac training from your apprenticeship or degree program.
I don’t have exact salary wages for Hvac technicians that are just getting there foot in the door straight out of school but I have been in trade for a minute, and from my experience if you are working in Florida, hourly wage will be between $15-$17 an hour. This is also the typical salary range for the technician that’s in an Hvac apprenticeship training program, of course your state may vary. But wait, there’ s more, much more to it than that.
I know it’s going to be hard to pay back that $15,000 or more student loan just making $15 an hour, but I can tell you this if you are working in Florida, Arizona, or anywhere for that matter when the demand for Hvac is in, and are working for a reputable company, then you can get some serious overtime. If your job requires you to go on-call you can make even more money. Sure you won’t get much sleep or have much of a life during the work week but when that check comes in it will all be worth it.
If you think that you are going to get burnt out working long hours, remember that air conditioning and heating is seasonal, and I don’t care how many customers your company has there are going to be slow times where you will only be getting 30 hours a week or less, especially if you are just starting out.
Higher Paid Hvac Technicians
Senior technicians can make $30 an hour or more, but what exactly separates the senior hvac technician from the novice just getting out of school? Well basically the senior technician will be able to troubleshoot and make repairs faster and more efficiently, just because they have been in the field longer and have seen the same problems occur over and over.
The more specialties the service technician has the more they will get paid (should anyway). For instance if you only know how to work on residential equipment, then you are limited to only residential. What happens if a chiller goes down and needs to be fixed? What about service calls on commercial DX systems, refrigeration calls, etc. The more things that you are able to fix the more calls you will be able to get, the more higher paid jobs you will sell, and ultimately the more money you can make.
Higher paid Hvac technicians also should have every tool needed to complete jobs. I have previously wrote a list of common hvac tools needed for the service technician. Tools are not cheap and are usually acquired over the years, as many Hvac companies will supply a certain amount of tools for the technician, but not all of them.
Hope this clears up some of the speculation of how much hvac technicians get paid, if you are in a different state than Florida or a different country, feel free to share with us hvac technician wages for those that are thinking of making this a career.
This is one of the most confusing topics that has many different answers, as there are different types of warranties that cover certain things such as parts, and other types of warranties that cover labor and parts.
Most manufacturers for residential units will have a 5 year parts warranty that will cover any failed component within the system, although more manufacturers are offering up to 10 years on parts now. Some of these parts are the evaporator coil, compressor, fan motor, blower motor. The most common misconception is that just because a unit is under manufacturers warranty does not mean LABOR is covered also.
If it’s a part such as a capacitor that goes bad, and the air conditioning service technician sticks you with a $200 bill, that’s all for the labor to diagnose, repair, and ensure that the air conditioning system is functioning properly. Though don’t take that number to heart for the price of a capacitor replacement it could be a lot less or lot more, especially if the service is being done after hours.
The other type of warranty that I would personally recommend to anyone that purchases a new air conditioning system, is a 10 year extended warranty. It will be an additional cost to your new system but it will more than likely pay for itself with just a couple service calls.
You may need it and you may never have anything go wrong with your air conditioner, but for the competitive prices that are out there for extended warranties, it’s well worth the piece of mind your going to get should you have a bad compressor or evaporator coil 6 years down the road.
So How Do I Find Out if My Hvac System is Under Warranty?
You are going to have to call the manufacturer of your air conditioning system. You are going to need a couple pieces of information, such as the model# and serial# from both the air handler and condensing units. If you have a Carrier or Bryant you are going to need the product# and serial#. Should you call for service from an air conditioning company they should be able to find out all this information for you with no problem.
What Does an Extended Warranty Cover?
There are different Extended Warranty companies but from my experience they will cover all major components within the system and the labor. Some of the things they won’t cover are a gas and go, which is just filling up the system with freon. If there is a freon leak, the hvac service company will have to find the leak and make the repair, and within the repair the freon will be covered by the extended warranty in that case.
Most Extended Warranty companies require that you get preventative maintenance done on your air conditioning system at least annually. Air conditioners are not designed to run efficiently without having maintenance at least yearly, you wouldn’t expect to drive your car for ten years without changing the oil or replacing the battery would you?
Hvac Warranty Tips and Recommendations
I will say it again – get an extended warranty if you can. It will last 10 years from the date of installation. Should you have had a new Hvac unit installed within the last couple years you may still qualify for an extended warranty.
If you don’t have an extended warranty and you keep having to have an hvac technician gas up your unit with freon, you need to get the leak fixed. There have been instances where an evaporator coil keeps leaking and a technician would keep gassing it up every six months, and before you know it that evaporator coil, that part, is out of warranty. Pay to get the leak search, it could be the difference of $1000 or more for the part if it’s out of warranty.
To cover all the air handler parts and accessories I would have to write a book, especially considering all of the new communicating systems that are out there. This is supposed to be Hvac training for customers to learn more about their components of the split air conditioning system. To learn more about the condensing unit components check out my post here.
I am not going to get into the ins and outs of these fancy new communicating systems and variable speed motors and modules, but just go over the basic parts and accessories that will find in your central air conditioning air handler, which is almost always located indoors.
So lets first go over the basic air handler parts located in your residential central air conditioning system.
Evaporator Coil– Next to the compressor, this is usually the most expensive part to get replaced should it go bad. And by go bad I mean that the evaporator coil is leaking refrigerant, which is very common for Trane copper coils made from early 2000-2010. The evaporator coil is where the inside part of the heat transfer takes place, and any obstruction such as dirty filters or dirty coils will reduce the efficiency of the unit as a whole.
Condensate Drain Pan – The drain pan catches the condensate that falls off the evaporator coil, which then directs the condensate to piping that goes either outside or a sewer system. Drain pans can be a semi-expensive repair if they get cracked and start leaking water as usually the evaporator coil will have to be removed for replacement of the condensate drain pan.
Metering Device – TXV or Piston
Metering devices are usually mounted inside of the air handler on the suction line. There are two typical types, which are the more reliable fixed piston metering device, and the TXV or TEV, which meter the refrigerant more efficiently but fail way more than a piston metering device does. Unfortunately nearly all the new split residential air conditioning systems come with a TXV metering device.
Blower Motor and Wheel – Newer, high SEER rated systems have variable speed motors, along with a module, controlled by a computer board, and computer signals, and all sorts of other safety and efficiency features that give us technicians headaches. But basically in simple terms you have a motor and you have wheel, which is inside what us Hvac Technicians call a squirrel cage, and its job is to suck in the hot or cold air inside of the residence.
Transformer – On residential units the transformer is almost always located inside of the air handler. It’s main purpose is to take high voltage 208-240 and make it into 24 volts. 24 volts in air conditioning is used as a control voltage, such as thermostats, safety switches and such. It’s good practice to always make sure these are protected by a 3-5 amp fuse, so if you get a low voltage short it blows the fuse and doesn’t fry the transformer. In the picture this fuse is on the blower motor relay board.
Blower Motor Relay – Controlled by 24 volts and contacts are normally open, when 24 volt power is applied the contacts close making a high voltage connection. These can look like little black switches with 4 or more spade connections or they could be a small like computer looking board such as the one pictured.
Thermostat – Essential to be able to regulate the temperature to your desired comfort. These days there are thermostats that can control humidity, be programmed to turn off when you go to work and turn on when you get home, to being able to be regulated from thousands of miles away through an internet connection. In the near future I will be dedicating an entire post to Hvac thermostats trying to cover every aspect possible.
Accessories for Your Air Handler
Electric Heaters – Electric heat will consist of one or more heating elements, along with a contactor or some type of relay to control when the heating elements are to engage. Other types of relays may be involved in electric heating also such as sequencers, and also involve safety devices such as temperature limit switches which will shut the unit off by breaking the electrical connection if the elements get to hot.
Water Safety Cutout Switch – In the event that your condensate line gets clogged, or your condensate drain pan gets cracked or warped, instead of the condensate pouring over onto the floor or ceiling, the water safety switch will cut off the 24 volt supply which will turn the unit off, preventing further damage. Water safeties come in many different varieties, from the super efficient water gards to the less reliable SS1 float switches. Either way its always good (and code in most cities) to have a primary and secondary water safety cut out switch.
Ultraviolet Lighting – Studies have shown that the air outside is up to 10 times cleaner than the air inside our homes that is constantly being recirculated. One reason for this are the UV rays from our sun do a great job of neutralizing airborne bacteria and viruses. By putting a UV light in your air handler or duct work, its almost like having a mini sun in your home doing the same thing by purifying the air inside of your home. These lights are so powerful though, if you look at them while they are on, they can damage your vision or even blind you, just as if you were staring at the sun.
High Efficiency Air Filter Boxes – For those that are concerned about air quality high efficiency filters that are longer in width provide more filtering capacity without restricting air flow compared to the purple ones you get at home depot. Basically there is a slight duct work modification that must be done right before the return grill if this was a modification you or your customer may be interested in.
The condensing unit in a split central heating and air conditioning system is located outside, and is also referred to as the ‘condenser’. This is where the warm inside air is ejected from the refrigerant to the outside. One quick way that you can tell if the system is doing its job is it would be blowing out hot air in cooling mode, and if you have a heat pump, such as a pool heater, the outside fan would be blowing out cold air. Let’s take a quick look at what parts make up the condensing unit in a split central air conditioning system with some free hvac training.
Compressor – This is the heart of the central air conditioning system, and in many cases is the most expensive part to replace. Compressors typically do not fail for no reason, compressor failure is usually do to poor installation skills, moisture in system lines, over charging or under charging the unit with refrigerant, or poor air flow inside due to undersized duct work or other air flow restrictions. The compressor compresses the refrigerant from low pressure low temperature gas to high pressure high temperature liquid in order to effectively remove heat from the inside of the home.
Condenser Coils – Another expensive part to the central air conditioning system that must be taken care of to get the most efficiency out of your unit. When outside air is blown over the condensing coils it removes the heat from the refrigerant and ejects it out the top of the unit. Washing the condensing coils with a water hose annually can ensure that they stay clean and free from obstruction such as dirt, dust and leaves.
Fan Motor and Blade – The fan moves the air from the outside, and pulls outside ambient air across the condensing coils and ejects the heat absorbed out the top of the unit. Unlike indoor blower motors, these are usually set at one constant speed. It’s important to keep at least a 5 foot clearance above the fan motor and blade, as hanging tree limbs and leaves can actually knock the fan blade out of balance over time.
Run Capacitor – Uses higher voltage to assist in starting and keeping the compressor and fan motor running by maintaining a correct phase of power. This is one of the most failed components and number one problem on service calls. On residential equipment there is a run capacitor for both the fan motor and the compressor, many air conditioning units these days are equipped with dual run capacitors that run the compressor and fan motor in one part.
Contactor – This is more like a relay, and completes the 208-240 volt circuit to power the compressor and fan motor. It’s engaged by 24 volts, so when 24 volts is applied from the thermostat to the contactor, the contacts will close making the connection to allow high voltage to go to the compressor and fan motor.
Heat Pump Condenser Components
Heap pump condensing units consist of the same operating parts as a cooling split system, but instead they have a reversing valve that switches the direction the refrigerant flows, and they also have a defrost control board.
Those are the basic Hvac condensing unit parts that are required to make the outside portion of the unit run, that’s it. Now with that being said there are also many other accessories and safety features that can be added to the condensing unit, and as systems get more efficient more and more accessories are being added. While when working right it can help the unit perform more efficiently and safely, but the more extras you have, the more better chance that one of these components may fail.
Condensing Unit Accessories
Start Capacitor – also referred to as a Hard Start, will increase the starting torque of the compressor. Many of the new Trane units come equipped with start capacitors and potential relays which remove the start capacitor once the unit is on line.
Low Pressure / High Pressure Switches – a safety feature that will prevent the system from running if a pressure drops below a designed setting for the low side or rises above a certain pressure for the high side. Low pressure switches will engage when there is a loss of air flow or lack of refrigerant. High pressure switches will trip when the system pressure rises to high, which generates many service calls for us, especially when painters that paint building cover the units up with a paint blanket while the system is running.
Compressor Time Delays – Prevents the compressor from short cycling or even running backwards by locking out the low voltage for a set desired time, usually between 2-5 minutes. If you have a sudden power failure, the compressor will suddenly lose power and then when power is restored will try to start again which can be detrimental to the equipment. A time delay can prevent this from happening. Although these days most of the newer digital thermostats have this feature built in to them and just need to be programmed into the thermostat.
If you would like to share any other Hvac condensing unit parts not covered here feel free to do so in a comment below.
With the proper Hvac Training you can lead a lucrative career that will open you up with job opportunities just about anywhere you go, as there is always a demand for heating, cooling and refrigeration to be repaired. Not to mention ventilation systems such as exhaust fans and whole home fans.
I’ve been an Hvac service technician for almost 10 years now so I wanted to share with you some of the things and situations that you might encounter while out in the field as a service technician. Unlike office 9-5 jobs, service technicians are more than likely going to see something different everyday, and also meet new people every day.
I also have those days where I am doing air conditioning repairs and maintenance and find surprises inside of units, as this one to the left a snake had gotten into the service area of the condensing unit and wrapped itself around the run capacitor, which fried the snake and at the same time shorted out the run capacitor. Not something that I wanted to see on a Monday morning on my first call, not to mention that I was hungover from the previous Sunday.
Working in Florida it’s actually quite common to find snakes hanging out around, inside and under condensing units, one of the reasons that I always wear pants to work instead of shorts. I have also found black and brown widows hiding out inside of condensing unit service panels, as well as families of roaches. For this reason I always take caution when opening up service panels on condensing units as you never know what might be on the other side of that panel.
Here’s another thing that scared the crap out of me while I was doing preventative maintenance around a bunch of condensing units that were surrounded by leaves, and under all of leaves were more than 10 poisonous Cane Toads. Which I can deal with better than snakes as they will hop away from you, and as long as you don’t lick them you should be in good shape.
The Hvac Technician is one that is going to have a new challenge every day. If you are new to the field there are going to be days that you work 12 hours or more. On-call rotation is usually mandatory at most companies and for many known as a hell week because you are working 12+ days for the entire week, especially during peaks seasons, but once that over time pay check and maybe that commission check comes in, you know that all those hard long hours were worth it.
Is your air central air conditioner freezing up? If so, this could be either an easy fix or a more difficult one that would require a licensed hvac technician that has had the proper hvac training to diagnose. I am here to educate customers and help younger technicians learn the trade better, so this should benefit those that fit into that category.
Basically when you get a certain amount of suction pressure drop, the refrigerant is going to be at a temperature that will cause condensation to freeze up, and if it runs long enough like this, it can freeze up all the way from the air handler to the condensing unit. This will cause the dreadful common problem of a frozen air conditioner.
This can cause major havoc in the refrigeration cycle, and actually have liquid refrigerant slug back to the compressor, which most compressors don’t like, ultimately leading to further Hvac component damage.
If your air conditioning line is frozen, not only will this result in a block of ice covering your evaporator coils, preventing any air from passing through, it can really damage the heart of your system which is the compressor.
Causes for Central Air Conditioner Freezing Up
1. – Clogged Air Filter, Coils, or Obstruction in Front of Return Grille
Your air filter needs to be checked monthly, especially if you have a lot of people living in the home, have pets or have carpets. From my experience the more occupants that are in a home the faster that air filters get dirty. If you are having remodeling done in the home there is going to be a lot of dust in the air, and most of that dust is getting sucked into the central air conditioning system.
Air filters can get clogged enough to where little to no air can pass through, and when that happens suction pressure drops and your evaporator coil will freeze up.
Some people may just toss the old filter out and never replace it. If they do this (which I have seen plenty of times), the air will pass through like normal but then debris and other particles are going to build up on the evaporator coil, and in the future, the coil will be clogged, which is much harder to fix than just replacing the air filter, as you will have to have the coils professionally cleaned.
If you have your central air conditioning air handler located in a closet, don’t store stuff in there, especially plastic bags and paper, you know stuff that will be sucked up when the ac kicks on. Also avoid putting couches, laundry baskets, and other obstructions directly in front of the return grills.
From my experience as an Hvac technician this is the most common cause of a central air conditioner freezing up.
2. – Low on Refrigerant
Another major cause that makes air conditioning units freeze up. This unfortunately has to be fixed by a professional, and when I mean fixed, I don’t mean just add gas and go. Sure that may be the cheap way (for now) but R22 has recently tripled in price, and customers that have leaking systems are going to find that out quickly, that the yearly or monthly gas and go is not going to be in their best interest.
*Updated for 2017. R-22 is set to be phased out of production in the next couple of years. The price is going to only increase. Drop in replacements for R-22 seem to be the way to go. Though the cooling capacity isn’t as good at transferring heat as R-22. So if you have an older R-22, central air conditioner freezing up, you may want to consider a system replacement if the repair to get it fixed is high.*
Your technician should perform a full system leak search and fix the problem accordingly, which in most cases is not going to be cheap.
3. – Bad TXV Valve
If you are an inexperienced HVAC technician and you suction pressure is low after thawing an iced up air conditioner, your first instinct would be to add gas and the problem will be fixed. But if you keep adding gas, and that suction pressure stays the same and the head pressure keeps rising, this means that you have a restricted TXV valve. Sometimes this restriction can be cleared and the system will operate again, but it could happen again, best bet is to offer the customer a new TXV valve. Restricted TXV valves in some situations may be the reason for central air conditioners freezing up.
4. – Non Functioning Blower Motor
If the blower motor on the air handler is not operating, then you have refrigerant running through the lines not able to absorb any heat from the space that is supposed to be being cooled. There are several reasons why blower motors failed depending on whether they are variable speed, constant or communicating, so this again is up to a qualified air conditioning technician to determine. This may be one of the more expensive hvac repairs to fix a frozen central air conditioner.
5. – Low Ambient Temps
There is no set temperature at which coils will start to freeze up as different manufacturers design the coils to cool at a certain temperature. But a good rule of thumb is don’t try to cool the home below 72 degrees. If it’s below 70 degrees Fahrenheit outside, don’t even try to bump the thermostat down. Even though the unit may not freeze up, that coil is getting too cold and you risk sending liquid refrigerant back to the compressor, which is a bad thing. This is a very easy fix to stop your central air conditioner freezing up, don’t set the thermostat too low when its not that hot outside.
6. – Pitted Contactor on Condensing Unit
A contactor is a mechanical device which opens and closes the circuit to high voltage, which is controlled by low voltage (the thermostat). When the contactor gets pitted it basically welds itself shut, and won’t unstick. So basically if you have your thermostat off, and the inside unit is not running , but your outside unit is constantly running and won’t shut off, then most likely the contactor is pitted and needs to be replaced. If you are a homeowner and this happens just shut the breaker to the outside air conditioning unit off and call for service.
So what should you do if you discover your air conditioning has frozen up?
First go to cause one and see if that solves your problem, but either way you are going to have to thaw out that frozen coil first!! Set your thermostat to the off position and turn the thermostat to ‘fan on’. Check to see if your outside unit is still running with the thermostat in the off position. Then call for service. The reason you want to turn the fan to the on position is that it will help thaw out that frozen coil faster (given the blower motor isn’t bad…). Because if the service technician shows up to your door and the coil is frozen, there is nothing he or she can do to troubleshoot a frozen air conditioning coil until it’s completely thawed, nothing.
Having your system maintenanced a couple times a year, along with routine filter changes, can greatly reduce the possibilities of your central air conditioner freezing up.
Many of us Hvac technicians would love to do nothing but fix broken air conditioners, but the nature of the business is many people like to just have their central heating and air conditioning systems checked out, or a ‘tune up’. Those that are just starting in the field with minimum Hvac training may find themselves doing lots of tune-ups and preventative maintenance before they are constantly out in the field repairing Hvac systems.
What Does an Hvac Tune-Up Consist Of?
Many companies may have different procedures that they implement when cleaning your hvac system. But below is a list of what I typically do on an air conditioning system.
Clean/Replace Air Filters – This should be done or at least checked once a month. When performing a tune-up I ensure that the air filters are clean so that there is nothing restricting the air flow. As I have stated before dirty air filters can cause loads of problems such as the unit icing up which could cause further damage to your compressor.
Clean Evaporator Coils – If the evaporator coils are cleaned at least once a year they should be semi-easy to clean, which can usually be done on a tune-up. I use a soft bristled brush and coil cleaning solution to do this, then spray down with hot water to wash the solution off. If the coils are extremely dirty or there is difficult access to them, I will then charge extra to perform this.
Wipe Down Inside Air Handler – A clean unit is a happy unit. I would wipe down the blower housing, wires, and rest of the inside of the air handler. Should the blower wheel be caked up with dirt and debris though, that would be an extra charge to pull and clean.
Clean the Condensate Drain Line and Pan – This is probably the most important check of air conditioning tune-up, as it causes the most problems and also the most damage. I am not going to get too much into this as I have already dedicated a post about this here.
Clean the Condenser Coils – In many cases this is much more easier to clean than the evaporator coils, as usually all it requires is a garden hose and spray nozzle. Just to be safe ensure that the power is off to the condenser and the thermostat is in the ‘off’ position. If you are a certified technician with hvac training and want to do a thorough job of washing the condensing coils, then remove the fan motor and spray from the inside out.
Check Refrigerant Charge and Amp Draws – This should only be performed by certified air conditioning technicians that have had the qualified Hvac training. This is not something for DIYers, and it’s also illegal if you don’t have an EPA license to handle refrigerant. I usually take amp draws on the compressor common wire, fan motor and indoor blower motor and compare them to the nameplate to ensure that they are in specs.
Tighten All Electrical Connections – This is everything from the wire nuts to the lug nuts to the inside and outdoor disconnects. Loose wires can cause arcing and breakers to trip, and again, should only be done by professionals.
How Much Does an Air Conditioning Tune-Up Cost?
Depending on where you are located geographically and how many systems you have the price can vary. But in my opinion no less than a hundred dollars. When you think about it the technician is going to be there at least an hour (if done properly) and not to mention the chemicals needed to clean the system components mentioned above. Not to mention gas, travel time, and cover other expenses such as insurance etc.
Just be cautious if you choose one of these 25 point tune-ups for $30-$40, as they aren’t making any money that little amount, in many cases they would lose money. That’s normally just to get their foot in your door so they can sell you something you might or might not need.
Installing a thermostat for your central air conditioning or heat pump system can be a do-it-yourself task if you are handy enough. It can also be pretty simple given that you have the right tools. But before reading this and following through, make sure that you view our disclaimer as we are not going to be held responsible if you damage your equipment or injure yourself. If you still feel like you have enough common sense to follow this guide and install a thermostat yourself and save money, then read on…
Determine What Type of System You Have First
The following thermostat replacement tutorial is covering a split system, single stage compressor, using a 1F86-344 White Rogers digital thermostat. No zones. No heat pump, although if you have a heat pump system following this tutorial should work also, as there are only two extra wires that you would have to hook up which would be ‘B’ (brown) and ‘O’ (orange).
DIY Thermostat Replacement
Removing the Old Thermostat
First thing you want to do is turn the power off to the air handler or furnace. Then you are going to remove the cover from the old thermostat. Usually this is done by pulling from the top of the thermostat in the middle, towards you and the cover should pop right off. Some thermostats may have a small set screw so don’t go yanking it off the wall if it doesn’t come off with a little force.
With your small flat head screwdriver loosen all of the set screws from the wires and using you needle nose pliers, remove the wires from the set screws. Unmount the screws securing the old thermostat and then you should be able to pull the thermostat off of the wall.
Installing the New Thermostat
Pop the cover off of the new thermostat, note that some T-stats have a small set screw that you will have to loosen to get the cover off, but this should be covered in the installation instructions. The I will usually get a pen and a torpedo level and get an idea of where I am going to mount the thermostat. Once I got it flush against the wall with the wires through the hole I will make two marks with my pen. Pull the thermostat back from the wall and insert your drywall anchors.
Now just put the thermostat flush against the wall pulling the wires through the middle and mount the thermostat with the screws provided. Make sure that you get your colors right when hooking up the 24volt wires. Lots of times old wiring white can look like brown and vice versa.
The R (red) is the 24volt power to the thermostat.
The G (green wire) is for the blower fan.
The W (white wire) is for the heat.
The Y (yellow wire) is for the compressor and outdoor fan motor.
O and B would usually be for the heat pump.
If you have Y2 or W2 terminals are for multi-stage systems.
RC and RH terminals should have a red jumper connecting them. The only time this should be removed is if your cooling and heating have separate transformers, which in most cases they won’t.
The C terminal (usually black or blue) is for the common hookup, which is optional and requires a little more technical know-how to hook up, not really recommend for diyer’s as you can blow up transformers if hooked up wrong, and should be left to someone that has at least a little bit of hvac training as you will have to be able to locate the transformer (which is usually in the air handler in residential units).
If you have an AUX terminal (usually white wire) then this is usually for emergency heat. This would kick in when your heat pump can no longer keep up with the heating load.
Hooking up the optional common wire will get power directly from the air handler with digital thermostats. Some advantages to this is that you will not need to be replacing the batteries every year. Another benefit from this is if you have an optional but oh-so-recommend water safety switch, and it happens to trip, it will make the thermostat blank.
A little help diagnosing an air conditioning problem because if you see your thermostat’s blank then you know that you are either missing 24volt power, or you are missing power from the air handler altogether.
Hooking up Common Wire in Digital Hvac Thermostat
First with the power off I connect the optional common wire up to the thermostat. Then I open up the air handler and locate the transformer. On the 24 volt side of the transformer follow the common wire to where it hooks up with the same string of wire that’s going out to you compressor, and this is where I tie the blue wire into. In the picture to the right (click to enlarge) I followed the common wire to the relay control board, and the common wire comes out at the C terminal (brown wire).
Or if you wanted to you can splice the common wire and tie it in where ever you want. Some air handlers have a terminal block similar to the one in your thermostat, if so just hook it up to the ‘C’ terminal. Just make sure that you hook it into the common wire and not the 24volt wire or you WILL short out you transformer.
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