Air Conditioner Installation & Repair
Air Conditioner repair services, air conditioner maintenance and spare parts inMombasa and Nairobi – Kenya.
5 Reasons Why Your Air Conditioner Stopped Working
Mechanical Issues
An air conditioner’s job is to get rid of the heat inside your home and bring in cool air, with the help of a chemical called refrigerant. AC systems have basically five components:
Fan
Evaporator coil (cools the air)
Compressor (electric pump)
Condenser coil (transfers heat)
Expansion device
Air conditioning units have two parts: one inside your home and one outside of it. A fan in the inside unit blows air through the chilled evaporator coil, cooling your house, via air ducts. Meanwhile outside, the compressor, condenser coil and another fan vent the hot air coming off the refrigerant. The expansion valve regulates the amount of refrigerant moving between the evaporator and condenser coils.
Any of these components can experience mechanical failure. If the motor on your fan is not working, the outdoor unit can’t get rid of the heat. If your compressor is damaged, the refrigerant can’t circulate between the inside and outside units [source: Coolray].
Replacing some of these parts is very expensive (particularly the compressor) and may not be much cheaper than replacing the whole unit. Having a trained technician give your unit a yearly checkup should prevent premature mechanical failure.
“Residential central air conditioning units are extremely reliable, which is why homeowners often forget to perform routine maintenance on them,” says Francis Dietz, vice president for public affairs for the Air Conditioning, Heating and Refrigeration Institute, says in an email. Nevertheless, these units “require attention for them to perform properly.”
4: Clogged Air Filter
Dietz says failure to replace the air filter on schedule is one of the most common reasons that an AC unit will stop working. “Homeowners who ignore this basic task, risk at the very least make their unit work harder than necessary just to try and push the cooled air through a clogged filter,” he notes.
“In extreme – but not completely uncommon – cases, a unit can be completely incapacitated and have to be replaced because the cool air, having nowhere to go, circulates back into the evaporator coil, causing it to freeze and fail,” he adds. The evaporator coil is a network of tubes, filled with a coolant called refrigerant, that remove moisture and heat from the air.
A clogged filter hinders the flow of air through the unit, reducing its efficiency and making it tougher to cool your house. Consumer Reports recommends that filters on central air conditioning units be changed once a month, especially if you have the air conditioning running constantly, or have pets who shed fur.
To make it easier, Dietz says, many of today’s advanced thermostats automatically notify homeowners of the need to replace a filter.
3: Low Refrigerant
Inside your warm house, cold liquid refrigerant evaporates on the evaporator coil, turning into gas. The hot refrigerant gas is then pumped outside into your system’s condenser, where it transfers the heat to the outside air and reverts into a liquid again and the cycle continues [source: DOE].
As you can imagine, if the refrigerant is low, the air conditioner won’t cool very well. The amount of the refrigerant in the unit must exactly match the manufacturer’s specifications
There are two reasons why you would have a low level of refrigerant. One is that when the system was installed, not enough was added. But more likely, the level is low because your system has developed a leak.
Leaks are the cause of 90 percent of the cases of low refrigerant [source: ServiceExperts]. So, simply adding more refrigerant isn’t going to fix things. Bring in a trained technician to find the leak and fix it. After the repair is tested, the technician can charge the system with the correct amount of refrigerant and your system should be set.
Nearly all current AC systems use halogenated chlorofluorocarbons (HCFCs), aka R-22 or freon, as a refrigerant but these are being phased out for environmental reasons. Between 2020 and 2030, ozone-safe hydrofluorocarbons (HFCs) are expected to become the norm
2: The Outdoor Condenser Unit is Blocked
Careless outdoor landscaping and/or neglect of lawn care may be another reason that your house is so hot.
“Shrubs and other plant life can obstruct airflow to the [outdoor condenser unit], which relies on it for proper operation,” says Dietz of the Air Conditioning, Heating and Refrigeration Institute.
If the condenser coil is covered with dirt or leaves, the heat transfer is impeded and the unit has to work a lot harder to do any cooling, leading to possible system failure [source: Rosone].
“Homeowners should take care to ensure a decent-sized berth around and on top of their outdoor unit and also periodically use a garden hose (not a pressure washer), to remove dirt and debris that might be caught in the unit’s fins,” says Dietz. “Lawn clippings and dirt kicked up by heavy rainfall are common culprits here.”
Consumer Reports recommends allowing 2 to 3 feet (60 to 91 centimeters) of space between the unit and any plants or backyard structures, and 5 feet (1.5 meters) between the top of the unit and any trees that hang over it.
1: The Unit Is Too Small or Has an Old Thermostat
One big reason for malfunctions is that a lot of home air conditioning systems aren’t installed correctly in the first place, says Todd Washam, director of industry and external relations for the Air Conditioning Contractors of America, a trade group that represents about 4,000 contractors across the U.S. and writes standards and manuals for the industry.
Washam says that it’s crucial for installers to make careful calculations beforehand on how much cooling a home will need, and to make sure that the air conditioning unit is matched with properly-sized ducts. If the ducts are too small, he says, the unit will have to work harder to cool down the house. That, in turn, increases wear and tear on the components and shortens their lifespan. And if the unit itself is too small for the space, the house will never get cool enough.
Another problem can arise if your thermostat isn’t correctly calibrated, particularly common if you have the old-school dial control version. If something is wrong with your thermostat, your air conditioner won’t get the necessary instructions on how much to cool your house. Remedy the problem by either having the thermostat recalibrated by a technician, or replacing it with a newer programmable digital unit, which will be more precise and help you to save energy as well. Some of the new devices can even be programmed remotely using your smartphone or tablet, which is a nice convenience.
Lots More Information
How To Repair Room Air Conditioners
Room air conditioners, also called window units, work the same way central air conditioners do. They are smaller than central systems and often more expensive to operate. Depending on its size, a room unit may cool only the room in which it’s located, or it may be able to cool adjoining rooms as well.
Sandwiched between the coils are a compressor, two fans, a motor, and thermostat controls. Dirt is the biggest enemy of window air conditioners; it can lower the efficiency of the evaporator coil, block the operation of the fan that blows out the cool air, clog filters, and block drain ports.
The coils, the compressor, and the motor of a room air conditioner are sealed components, so any repairs to them should be left to a professional service person. However, you can make minor repairs, and regular maintenance will keep your unit running well. When extensive repairs are needed, you can also save the cost of a service call by removing the air conditioner from its mounting and taking it to the repair shop.
During the winter, room air conditioners should be protected from the elements. Either remove the unit from its mounting and store it or cover the outside portion of the unit with a commercial room air conditioner cover or with heavy plastic sheeting, held in place with duct tape.
Caution: Before doing any work on a room air conditioner, make sure it’s unplugged. Room air conditioners have either one or two capacitors, located behind the control panel and near the fan. Capacitors store electricity, even when the power to the unit is turned off. Before you do any work on an air conditioner, unplug it and discharge the capacitor or you could receive a severe shock. The unit’s owner’s manual will show the location of capacitors and tell how to discharge them. Otherwise, let an air conditioning technician do it.
Now that you’re ready to work on your air conditioner, try to determine exactly what needs to be done. Look for your problem, and solution, on the chart on the next page.
ROOM AIR CONDITIONER TROUBLESHOOTING CHART
Problem Possible cause Solution
Unit doesn’t run
1. No power.
1. Check cord, plug, and outlet.
Check for blown fuse or tripped
circuit breaker at main entrance
panel; restore circuit.
2. Motor overload
or safety shutoff. 2. Wait 30 minutes; press reset
button. Repeat if necessary.
3. Switch faulty.
3. Check terminals and insulation; if
burns are evident, replace switch. If
switch looks all right, call a professional.
Fuses blow 1. Circuit overloaded. 1. Put on different circuit.
2. Voltage low.
2. Call a professional or the
power company.
Cooling
inadequate 1. Thermostat set
too high. 1. Lower thermostat setting 5°.
2. Filter dirty. 2. Clean or replace filter.
3. Coils dirty. 3. Clean coils.
4. Condenser blocked
from outside. 4. Make sure outside of unit
is not blocked.
5. Motor faulty. 5. Call a professional.
6. Compressor faulty. 6. Call a professional.
7. Coolant leak. 7. Call a professional.
Fan runs, but
unit doesn’t cool 1. Thermostat set
too high. 1. Lower thermostat setting 5°.
2. Thermostat faulty.
2. Test thermostat; if faulty,
replace, or call a professional.
3. Coils dirty. 3. Clean coils.
4. Motor faulty. 4. Call a professional.
5. Compressor
faulty.
5. Call a professional.
Unit cools, but
fan doesn’t run 1. Control switch
set wrong. 1. Reset switch; try different settings.
2. Fan clogged. 2. Clean and tighten fan blades.
3. Fan blades bent. 3. Straighten fan blades.
4. Fan motor faulty.
4. Replace fan motor or
call a professional.
Unit turns on
and off repeatedly 1. Coils dirty.
1. Clean coils.
2. Filter dirty. 2. Clean or replace filter.
As you can see, there are many parts that can fall into disrepair on an air conditioner. You can learn how to fix many of these, such as the filter and coils, on the next page.
Filter, Power Cord, Coils, Switch, Drain Ports, Motor and Compressor
The filter, power cord, coils, switch, thermostat, drain ports, and fan are important to service on a routine basis to avoid larger problems. Below are guidelines on how to maintain these key parts.
Filter
At the beginning of every cooling season and once a month during the season, remove the front grille and clean or replace the filter. If you live in a very dusty area, clean or replace the filter more often. Most room air conditioners have a washable filter that looks like sponge rubber.
Clean the filter with a solution of mild household detergent and water; rinse well. Let the filter dry completely before reinstalling it. Some units have a throwaway filter, similar to a furnace filter. When this type of filter becomes dirty, replace it with a new one of the same type.
Power Cord
The power cord that connects the air conditioner to the wall outlet may become worn and fail to supply electricity to the unit. To check the cord, remove the control panel. Unscrew the cord terminals and then attach a test wire across the bare lead wires.
Hook the clips of a volt-ohm-milliammeter (VOM) set to the RX1 scale to the prongs of the cord’s plug. If the meter reads zero, the cord is functioning. If the meter reads higher than zero, replace the cord.
Evaporator and Condenser Coils
Clean the evaporator and condenser coils at the beginning of the cooling season and every month during the season. If you live in a very dusty area, clean the coils more often. Use a vacuum cleaner on these components.
If the fins on the coils are bent, straighten them with a fin comb, sold at most appliance parts outlets. A fin comb is designed to slide into the spaces between the fins. Use it carefully as the fins are made of light-gauge aluminum and are easily damaged.
Switch
The selector switch, located directly behind the control panel, turns the unit on. If the air conditioner does not run at any setting, and it is receiving power, chances are the switch is faulty. To correct the problem, remove the control panel and locate the switch. Check the switch terminals for burnt insulation or burn marks on the terminals. If you see any indication of burning, replace the switch with a new one of the same type.
The switch is held to the control panel or frame with screws; unscrew it and connect the new one the same way. If you determine the problem may not be the switch, call a professional service person.
Drain Ports
As the air conditioner operates, condensed moisture and water vapor from the evaporator coil are funneled through drain ports or an opening between the partition in the middle of the evaporator coil and the condenser coil. At this point, the fan blows the moisture against the condenser coil, where the water is dissipated.
Drain ports can become clogged with dirt. The result is water leaking from the appliance, usually through the bottom of the grille. To prevent clogging, clean the ports with a short piece of wire hanger or the blade of a pocketknife. Do this at the beginning of every cooling season and every month during the season. Also check the condenser side of the air conditioner. Some models have a drain port along the bottom edge of the cabinet frame. If your air conditioner has this drain port, clean it out when you clean the other ports.
Motor and Compressor
If problems occur in the motor or compressor of the air conditioner, call a professional service person.
The problem may not be in the mechanics of your unit at all; it may be the thermostat. Find out how to check and replace a thermostat on the next page.
How To Test and Replace a Thermostat
The thermostat is located behind the control panel. Here’s how to test and/or replace the thermostat:
Step 1: Remove grille and control panel from unit. Thermostat has special sensing bulb attached to it; this part extends from thermostat into evaporator coil area. Its role is to sense temperature, which is controlled by thermostat.
Step 2: Remove thermostat carefully because you must return sensing bulb to identical spot later. To make replacement easier, tag location of bulb before you remove thermostat.
Step 3: Check thermostat with VOM set to RX1 scale. Clip probes of tester to thermostat terminals, and turn temperature control dial to coldest setting. If meter reads zero, thermostat is functioning properly. If reading is higher than zero, replace thermostat with new one of same type. If thermostat is held to control panel or frame with screws, clips, or metal tabs, connect new thermostat the same way the old one was connected.
Note: If the thermostat has more than two lead wires connected to it (not counting the sensing bulb wire) do not try to test or replace it. Instead, call a professional service person.
The fan in your air conditioner also needs routine maintenance. Learn how to keep it running smoothly on the next page.
How To Repair a Room Air Conditioner Fan
When a fan malfunctions, the problem is usually loose or dirty blades. If the fan won’t operate or if it’s noisy, cleaning and tightening will usually fix it. Here’s how to repair a room air conditioner’s fan:
Step 1: Open cabinet and locate fan.
Step 2: Clean away any debris with vacuum and soft cloth.
Step 3: Check fan blade on motor shaft for looseness. Blade is fastened to shaft with setscrew at hub of blade.
Tighten setscrew with screwdriver or Allen wrench. If air conditioner has round vent fan, tighten fan on motor shaft by inserting long-blade screwdriver through port in fan.
Fan is installed in its housing with bolts, and vibration can loosen these fasteners. Then tighten them with wrench.
Step 4: If fan has oil ports, apply several drops of 20-weight nondetergent motor oil (not all-purpose oil) to each port at beginning of cooling season.
Step 5: If you suspect fan motor is faulty, test it with VOM set to RX1 scale. Disconnect terminal wires from terminals, and clip probes of VOM to wires.
If meter reads between about 3 and 30 ohms, motor is functioning properly. If meter reads either zero or an extremely high number, replace motor.
To remove the fan motor, remove the fan, the power wires, and several mounting bolts. Install the new motor with the reverse procedure. However, if the condenser coil must be moved to get the fan out, do not try to remove the motor. Call a professional service person.
By following the routine maintenance mentioned in this article, you will be able to handle most problems that occur with your window air conditioning unit.
