Before you make that call, try this basic air conditioner troubleshooting guide. This guide will help you to diagnose problems with your typical ducted split type air conditioner. A typical repairman will cost you about one hundred dollars per hour. With a few household tools and a little bit of knowledge, you can do it yourself and save that money. (You provide the tools and we will help with the knowledge part.)You should ensure that the routine maintenance has been performed on the unit. If the air filter has not been changed in the past month, check to see if it is dirty. Begin your air conditioner troubleshooting at the thermostat by ensuring that the thermostat is on cool and that it is set lower than actual room temperature. This is to ensure that there really is a problem. It may seem silly but that is the first thing a repairman will check and you will normally still be charged a service call even if that is the only problem. If there is not, then, check to see if the fan on the outside unit is running.

If the fan on the outside unit is not running either, check to make sure that the breakers for the furnace/air handler and the air conditioner are on. If the breaker is not tripped, then the problem may be your thermostat, the furnace/air handler control board, or the wires between the furnace/air handler and the thermostat. If your unit has a condensate pump, check to make sure the reservoir is not full. If the reservoir is full, a limit switch will normally stop the air conditioner from running. You will need to repair or replace the pump.If the breaker is tripped, you can reset it by shutting it off and then turning it back on. If it trips again, then check the wiring in the furnace/air handler for signs of damage and repair as necessary.If the blower is running but the fan on the outside unit is not, then continue your air conditioner troubleshooting at the outside unit. If the blower isn't running but the fan outside is, the problem could be the blower motor, it's run capacitor, or the furnace/air handler control board.

If the fan motor is not running, then shut the power off to the unit. Then check all wire connections for signs of damage such as burning and repair as necessary. ac unit buzzing fan not turningYou should also check the wire connections in the compressor terminal box and repair if necessary.macy's ac unit You can use our capacitor testing guide to check the unit's capacitors and replace as necessary.coleman furnace parts calgaryContinue your air conditioner troubleshooting by turning the power back on to the unit and observe whether the contactor closes or not. If the unit does not start, look for a reset button. Some units have a high pressure cutout switch that can be reset. Then, use a voltmeter to check to see if you have power to the unit and 24 vac to the contactor's coil.

If you do not have power to the unit, you should check the wiring between the electric panel and the unit. If you do not have 24 volts to the contactor's coil, check the thermostat and the low voltage wires from the furnace/air handler to the condensing unit. If you have power to the unit and the coil on the contactor but the unit does not start, the unit's contactor may be bad.If the compressor starts but the fan does not, the condenser fan motor could be the problem.If the condenser fan starts but the compressor does not, the unit may be low on refrigerant, the compressor might be too hot, or the compressor might be bad. If the blower on the furnace is running, check to see if you see any frost or ice around the units. You might also notice water around the furnace. Is there ice on the copper lines going outside? If yes, then shut the outside unit off for a couple of hours but let the blower on the furnace run. This will allow the ice to melt. After two hours, you can continue your air conditioner troubleshooting.

Turn the ac back on and let it run for about five minutes. Now feel the larger copper line at the outdoor unit. This should be cold and have condensation on it. If it is not cold or if frost is forming on the line, it is probably a freon problem. You will need to call a repairman because of federal refrigerant usage regulations.If there is no ice or frost, then continue troubleshooting at the outside unit. If the condenser fan and the compressor both run but the cooling effect is not adequate, you should check the temperature drop of the system. To measure the temperature drop, measure the air temperature leaving the air handler and subtract it from the temperature of the air entering the air handler. The result should be about 15 degrees for a high efficiency unit and about 18 to 20 degrees for an older unit (SEER less than 10). If the temperature drop is significantly lower than that, the problem may be the refrigerant charge.If the temperature drop is significantly higher than that, then your air conditioner troubleshooting should focus on the system's air flow.

The evaporator coil, filter, or blower wheel could be dirty. This is usually the result of not performing routine maintenance on the system. It could also be caused by a duct system that is too small. This is usually the result of improper design or installation. You may be able to increase the blower's cooling speed or replace your existing blower motor with a variable speed motor to overcome that problem. Now, you can get live support or leave a message for the HVACrepairguy through Facebook Messenger.HVAC blower fan testing & diagnosis guide: This article discusses how to inspect and test a heating or air conditioning indoor air handler blower fan that is not working. We also discuss convector unit fans and we suggest diagnostic steps for squirrel cage blower fan squeaks and noises. Our page top photo shows an air handler unit located in a building's attic - we removed the cover to show the blower fan assembly just to the left of the red tag) in this image of a Lennox™ horizontal HVAC system.

The blower fan is located inside a horizontal air conditioning unit in many home air conditioning systems, especially when the air handler is located in an attic or crawl area. The location of a blower fan in vertical "up flow" or "down flow" heating and cooling systems is illustrated in additional sketches and photographs below. Initial, simple diagnostic checks of the air handler system are also described at DUCT SYSTEM & DUCT DEFECTS: Basic checks of the indoor air handler (blower), air ducts, and filter systems. My issue is about an air conditioner fan that just won't start. The fan motor is not seized, and we had a recent blower motor starting capacitor change. The blower fan relay appears to pull in okay, the electrical connections reseated and tight. But the cooling fan will still not start. This is an early 1990's York home air conditioning unit. Our photo (left), shows a modern blower assembly inside of an air handler. In this case the blower is a direct-drive unit - the electric motor that drives the air conditioner blower fan is mounted inside of and at the center of the blower assembly itself.

Other HVAC blower units may mount the motor separately from the squirrel cage fan, connecting the motor to the fan using a set of pulleys and a fan belt. For completeness we have listed some blower fan diagnostic steps that you have already tried, as well as additional things to check. The blower assembly is the green component in this illustration from Carson Dunlop Associates The Illustrated Home. Thanks to reader Randy Shaffer for suggesting this topic. Wall convectors are often used for both heating and cooling in commercial installations and high-rise apartment buildings. The unit shown has its own compressor mounted right in the cabinet, visible at lower center in Wall-mounted heating and cooling convector installations may be designed with one central heater or cooling system which feeds multiple units with chilled or heated water or possibly refrigerant from a single remote heating and cooling heat pump. Our photo (left) illustrates dual squirrel cage blower fans typically found in the bottom of a fan/convector heating or cooling unit such as this one found in a New York City apartment.

If the convector fan motors run and the squirrel cage fans spin but not enough air is coming out of your convector unit, turn off power and take a closer look at the fan blades themselves - you may need a flashlight and a mirror to make this check without disassembling the unit further than shown here (we removed the convector unit cover). Watch out: Dirt on the squirrel cage blower fan blades can significantly reduce airflow through the unit. We have seen a 40 to 50% improvement in air flow simply by cleaning this blower fan assembly, yet it's something people rarely check.Because even a small amount of dirt in the cupped fan blade edges reduces airflow significantly, but it's not visually obvious. You have to look carefully at the fan assembly. In our wall convector unit above you'd use a good flashlight and a mirror to inspect the blower assembly fan blades. Also check the cooling or heating coil fins for blockage by dust and debris - a more common source of air flow blockage at heating and cooling convector units like the one shown.

Our photo (above left) illustrates a condensate handling problem in the cooling convector unit for the same apartment unit introduced above. Air conditioning condensate was leaking inside of the convector unit due to a clogged condensate drain line. The condensate leak exited the bottom of the convector, ran through a raised floor cavity, entered apartment building walls, and ran around the wall interiors in a metal stud-framed wall sill plate where it led to major toxic mold contamination over a wide area, floor damage, and the need for costly cleanup and repair work. Details about wall convectors used for heating or cooling and about convector blower fans are found at WALL CONVECTORS HVAC and at FAN CONVECTOR HEATERS - HYDRONIC COILS Also see CONDENSATE HANDLING, A/C for more about air conditioner or heat pump condensate drainage handling. In our simple air conditioning (or heat pump) system sketch shown at left, the light blue fan shown at left in the sketch (above the red compressor box) is the outdoor compressor/condenser fan discussed

at FAN, COMPRESSOR / CONDENSER UNIT. The dark blue fan shown at right in the sketch is the indoor air handler or blower compartment or cooling coil fan found inside the building. This fan blows building air across the evaporator coil (or cooling coil) to cool and dehumidify indoor building air. We discuss this indoor fan at FAN, AIR HANDLER BLOWER UNIT. In a warm air heating system that does not include air conditioning as well, the indoor fan is still located in the indoor air handler and is discussed Question: What do I do about a squeaking, squalling squirrel cage? It doesn't do it every time the A/C comes on but more frequently than not. Not alot of room to see in there. The squirrel cage fan to which Erma refers is found inside the indoor air handler unit. This fan moves building air through the duct system and across heating and/or cooling elements to condition the air as it is then supplied to the building through supply ducts and registers. In an air conditioning system this is the dark blue fan shown in the right side of our sketch above.

For combined heating/cooling systems the same fan assembly can blow heated air into the building and an additional FAN LIMIT SWITCH will be found inside the furnace cabinet. More about HVAC blower fans including squirrel cage fans is in this article, above beginning at BLOWER FAN OPERATION & TESTING but to start addressing a squeaky blower fan, note that your fan may be repairable by tightening one or more allen screws that secure the fan cage assembly (or the bearings that carry the fan) to its housing through which passes the fan motor drive shaft. With power OFF for safety, if the fan and all components appear to have no loose screws or mounts, but you can still wiggle the fan from side to side, then the bearings are worn and need replacement. If your fan is pulley-driven, check also that the pulley is secure on the shaft and that the fan belt is not so loose as to be squeaking. I would not use WD40 on or near electric motor parts nor on greased bearings as it's not intended for a motor or bearing lubricant, though to be honest, I've sprayed WD40 on almost every problem that has ever arisen at one time or another.