Tip & How-To about Heating & Cooling

Air Doesn't Blow Cool Anymore? The Basics.

Does your air feel warmer than normal? Is there any air coming from the vents at all? Does you air conditioner feel like it's not the same?

These are some quick tips that can get you pointed in the right direction or maybe even fix the problem all together. Checking these few things will allow you to be more specific when posting your problems on FixYa too!

First, a quick checklist, then explanations and extra's below.

1. Make sure your air filters are clean!
2. Make sure power is on to the entire system. Breakers, switches, etc.
3. Make sure batteries are good in thermostat if equipped.
4. Make sure outside condenser coils are clean and free of debris.
5. Make sure your system is not frozen anywhere. Ice on line set, etc.
6. Make sure all system components are working:
a. Indoor blower motor.
b. Outdoor condenser fan motor.
c. Outdoor condenser compressor.
d. Air through all vents in building.

If any of these are not working, you can start there to trouble-shoot the issue. Sometimes more than one problem can occur from just one simple problem. Remember to get as much information from the component as possible to make it easier to diagnose!

1. Make sure your air filters are clean!
Dirty filters will cause restrictions in the airflow, decreasing efficiency, and causing more problems than you could imagine. Even a slightly clogged filter will change the refrigerant charge completely and it's cycle. Basically, if you have a 3 ton house, you need 3 tons of supply vents and 3 tons of return air. If you restrict your airflow, you can have as low as 2 tons venting out into a 3 ton house and the problem is obvious. No one can absolutely say when to change your filters! Your house is different from others, maybe cleaner, maybe dustier, but the filter will always need to be changed at different times. Just pay attention to how often you need to change it and go by your own schedule. Not changing your filters can lead to your coil becoming clogged which is usually pricey to have cleaned. A dirty or clogged coil is worse than a filter!

2. Make sure power is on to the entire system.
I don't know how many times I have had to charge for a service call to flip a breaker back on! It's not a good feeling, but in this field, time is money! Save yourself a few bucks by making sure there is power to all components. An indoor furnace will usually have a switch, just like a light switch, to turn on and off the power to service it. It will also have a breaker, more than likely a single-pole 20amp breaker. If you have an air-handler with electric heat, you will have 220v breakers, usually on the unit itself. The outside unit will have a 2 pole breaker, amperage varies, and should have an outside disconnect for service. Some older installations just have the breaker, either inside or out. These disconnects also should have fuses in the part you pull out. If you have any way to check continuity, you can check these too. If you suspect there may not be the correct voltage to any component, you will need a voltmeter or multimeter to check and trouble-shoot.
WARNING! If you do find a tripped breaker or blown fuse, only try one time to reset the breaker or replace the fuse! More than once can cause extreme damage to components and possible refrigerant loss. It needs to be checked to see what is grounded out and if it can be replaced/fixed.


3. Make sure batteries are good in the thermostat if equipped.
It may be a good idea to change them out if you suspect any problems with the thermostat. Many times I have came across a thermostat that looked fine, but the batteries were just low enough that it either wouldn't call at all, or wouldn't keep the call and shut back off. You can also check any household batteries with a multimeter set to the DC scale.

4. Make sure outdoor condenser coils are clean and free of debris.
Condenser coils need to be clean and clear for the operation of the entire system to function properly. It's the air movement through the coils that "condense" the refrigerant and pulls the heat out of the system. If they are dirty, it causes a number of issues that you may not even notice until it is too late. It will cause pressures to rise in the system, over-loading the compressor, and keep some of the heat that is supposed to be pulled out, in the refrigerant causing higher temperatures inside and a lot less efficiency! There are a number of issues, but I'm sure you get the point. The best way for someone to clean condenser coils is with your water-hose. With a gentle stream and being sure not to damage the thin aluminum fins to much. It's a good idea to start on top and work your way down slowly, being careful and try not to shoot the stream straight into the coils, pushing dirt further in between the coils. Instead, a nice 45 degree or more angle works best. Some people will have things like dog hair or cottonwood trees that mat up the coils. You can address this easier by first using a vacuum before spraying it down. People also ask me all the time about cleaning from inside out. For one, i don't think someone inexperienced should take a unit apart for a number of reasons and problems that could occur, and two, the only times you have to take a unit apart to clean it, from the inside or not, is when it's been highly neglected, or when your unit has doubled coils (two coils side by side). Spraying from the inside out can cause more issues by bending the aluminum fins inside when the outsides are already prone to being damaged by natural events. This will cause the system to fail completely.

5. Make sure your system is not froze anywhere. Line-set, coil, etc.
Ice forming on any part of your system is a sign that somethings wrong. The most common cause of this is your refrigerant charge is too low, causing the refrigerant to "boil" at 32 degrees or less, thus causing ice to form. You can also tell when your indoor coil is frozen by the reduction of airflow through the vents and a lot more water draining from the melting ice, which usually overflows out of the coil and down the sides of the indoor unit. Other things that can cause this are dirty filters and/or coil, blower motor not working, condenser fan motor not working, or problems with the metering device such as a restriction in the system. If it is not something that you think you can handle on your own and need to call a repairman or technician, make sure the system is 100% thawed out before they get there, otherwise they will have to leave until then and you may get charged more in time.

6. Make sure all system components are working.
These are things that make the trouble-shooting a lot easier and faster, especially if you are asking for help from someone that's not standing there with you! Sometimes it's easier to have someone there to help you try different things just to check more than one component at a time.

A. Indoor blower motor. If you have air blowing from the vents, then obviously the blower motor is working. Sometimes the blower does not come on with a call for cooling or heat, but that doesn't mean the blower is bad. Always turn the fan to the "ON" position to check this, but beware that other problems could still cause the blower not to work. If you turn the fan to the "ON" position and that's the only time it works, you could have a bad thermostat or other issues that you can check.

B. Outdoor Condenser Fan Motor. When the system is on a call for "COOL", the thermostat sends 24v to the outside condenser, pulling the contactor in allowing the 220v power to start the condenser fan motor and compressor. The fan motor should be pulling air through the coils and out of the unit, usually through the top, with plenty of airflow. If the fan motor is not working, you can turn the power off to the unit to make a few checks. First, try turning the blades yourself with a long screwdriver or something similar. It should rotate freely, if not, the motor has to be replaced. You can visually inspect the wire connections and capacitor inside the electrical compartment by first, making sure power is off to the indoor and outdoor units, just to be safe. Take off the cover, usually it's either 1/4 in or 5/16 in screws, and see if the connections are all on and tight. Inspect the capacitor, which is usually a round or oval object with terminals on top of it, making sure there is nothing leaking and that the top of the capacitor isn't "bubbled" out like it has exploded from the inside. These are only visual checks. To actually check the capacitor, you will need a multimeter that measures micro-farads. To replace these are simple and cheap if you do it yourself. Warning! Capacitors store electricity and can shock you with no power to the unit. Discharge capacitor by touching the terminals together with metal while holding it with an insulated handle, such as a insulated screw-driver.

C. Outdoor Compressor. The compressor is the component inside the condenser that pumps the refrigerant through the line-set. You can hear the compressor running most of the time, if you have doubts, you can hold the copper line-set and feel for vibrations. Believe it or not, the fan and the compressor can be hard to tell apart sometimes. The same visual checks can be made with the compressor as mentioned above with the fan motor. The only other thing you can do is feel on top of the compressor to see if it is really hot. Be sure the power is off! A really hot compressor can mean it has overheated and the internal thermal protection has tripped, causing it to shut off until it cools. This can be cause from the refrigerant charge, restrictions, or electrical problems.

D. Air blowing through vents through-out entire building. Be sure to go to every room and check for airflow. Broken, collapsed, or blocked ducts can cause major air loss and heating/cooling problems.

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