Common Repairs
Listed below are some of the more common repairs that we see
throughout the year, and the causes that lead up to the part not
working.
Electrical Components
Fuses
Contactor/Relay
Capacitors
Defrost Control
Gas Valve
Furnace Circuit Board
Outdoor Fan Motor
Indoor Fan Motor
Compressor
Piping Components
Refrigerant Metering Device
Reversing Valve
Restrictions
Indoor Coil
Outdoor Coil
Drain Lines
.::::.
Electrical Components
Fuses
The Fuses and circuit breakers in the electrical supply to your air conditioning
system have large demands. Their purpose is to prevent excessive load
on the supply circuit, which could overload the entire system.
Fuses can fail from age, a loose connection, an electrical
storm, a faulty electrical component in the unit, or from simply being
loose in their holder.
Typically, a faulty fuse will result in no operation at all or only the indoor circulating fan working. Back To Top
Contactor/Relay
Relays are electrically controlled switches that turn the motors, or
other components of the system, on and off. There are a variety of
relays in any given system and the thermostat operates most of them.
The largest relay is called the contactor, and it controls the power to
the compressor.
These devices can fail when the contact surfaces stop making
contact, become stuck in the on position, or they turn on the wrong
component. Also, each time one of these switches turns on and off, the
contact surfaces pit from electrical arching, eventually causing wear
and tear. Back To Top
Capacitors
A Capacitor helps your air conditioning systems' motor start from a stand
still and run efficiently. Capacitors are filled with an oil-like fluid
that acts like an insulator.
Capacitors can weaken over time decreasing the motors
efficiency. Heat can also cause them to swell, leak and fail. On
occasion, a capacitor's circuitry will open, and will need to be
replaced. A weakening capacitor usually has no noticeable effect on
your system's operation, however it could be causing the motor to
run warmer than normal, shortening its life expectancy. Once a
capacitor has failed, the motor will not run. Back To Top
Defrost Control
A Defrost Control limits the amount of ice that can form on you air conditioning
system. An electric heat pump heats the home by extracting heat from
the outdoor air. To do this, the system must operate at very cold
temperatures. By operating at these temperatures, the outdoor unit can
build up ice, decreasing its ability to heat. A defrost control will
turn off the outdoor fan and place the system into a type of cooling
mode to melt the ice.
A faulty defrost control in the heating mode can prevent the
system from going into the heat mode or allow excessive ice to build
upon the unit, resulting in poor performance. A failure in the cooling
mode can prevent the outdoor fan from running, resulting in a loss of
cooling. Back To Top
Gas Valve
A Gas Valve is found in a gas furnace. When a signal is received from
the thermostat, the gas valve controls the amount of gas needed for
heating.
A gas valve can fail from electrical or mechanical reasons.
Debris or moisture in the gas piping can cause a valve to stick in the
on or off position. A gas valve can fail at any time, but most fail
after sitting idle over the summer. Normally a gas valve failure will
result in no heat. Back To Top
Furnace Circuit Board
A Furnace Circuit Board performs a variety of functions, from normal
operation of the furnace, to the monitoring of the furnace's
safety circuits.
The furnace circuit board can fail for a variety of reasons.
The normal vibration of the system can weaken the solder joints in its
circuitry, causing a failure. A short, or electrical failure, of the
components connected to the module can damage the internal circuitry.
Also, if it becomes exposed to moisture or excessive dirt, the
circuitry can become damaged.
The failure of a furnace circuit board can have multiple
effects, ranging from the indoor fan not turning on in the cooling
mode, or a complete loss of heat. Back To Top
Outdoor Fan Motor
The Outdoor Fan Motor, also referred to as the Condenser Fan, draws air
through the air conditioning unit to cool it off. Often, this motor can be viewed
from the top of the outdoor unit and has a propeller type fan blade and
discharges air out of the top of the unit. Due to their location, these
motors are subject to year round weather conditions, in addition to all
of the indoor heat removed while cooling a home.
An outdoor fan can fail from wear and tear. Because they are
running every time the outdoor unit is in operation, these motors can
accumulate between one and two thousand hours of operation a year.
Also, the harsh desert conditions subject the motors to extreme heat,
weakening its electrical components.
In the early stages of failure an outdoor fan motor in the
cooling mode may work through the night and morning hours but overheat
and stop in the afternoon heat. This can result in the rest of
the system overheating and stopping for several hours. Once the motor
fails completely, the unit will no longer function. Continued running
with a faulty outdoor fan motor can stress the system and eventually
cause a compressor failure, and a much more costly repair. Back To Top
Indoor Fan Motor
The Indoor Fan Motor, or Blower Motor, circulates the air from the home
through the heating and cooling system. These motors run constantly
when the unit is heating or cooling, but can also be set to run even
when the air conditioning unit is off.
An indoor fan motor can fail from normal wear and tear, or
from electrical problems. If dust collects in the motor, it can cause
hot spots on the electrical windings and damage them. If dust forms on
the fan wheel, it may cause the wheel to spin out of balance. The more
out of balance a blower wheel is, the more stress it places on the
motor bearings.
Early signs of motor failure due to the bearings will be
increased operating sound. Total failure of the motor will result
in no heating or cooling. The system may try and work, but it will not
be able to circulate air from the home. If left to run in this state
for too long, other heating and cooling components can be strained or
compromised. Back To Top
Compressor
The Compressor acts as a pump to circulate refrigerant through the air conditioning
system. It resides in the outdoor unit, and like the engine of a
car, has an audible sound when in use.
Compressors can fail for a variety of reasons, including the
motor bearings simply wearing out. Most times, a compressor will be
strained by the failure of another component, such as a fan motor or
the capacitor. Electrical storms can cause problems for a compressor,
and almost always produce a noticeable increase in compressor
replacements. Early signs of compressor failure may be a decrease in
performance or an increase in operating sound. Total failure will
result in no cooling, or no heating from a heat pump. Back To Top
Piping Components
Refrigerant Metering Device
The Refrigerant Metering Device controls the flow of refrigerant
through the air conditioning system much like a traffic light controls the flow of
traffic down a street. All air conditioning systems will have at least
one refrigerant metering device, and heat pumps will have two.
Much of a system's efficiency is derived from the proper
operation of this device. Too little refrigerant flow will cause the
system to have reduced performance, and could cause the compressor to
overheat. Too much refrigerant circulating though the system could
overwhelm the compressor, causing damage. Often, a total failure of
this component will result in the system not cooling or heating at all.
Back To Top
Reversing Valve
Reversing Valves are only found on electric heat pumps and are used to
reverse the flow of refrigerant from the cooling mode to the heating
mode and back again. They reside in the outdoor unit, and all of the
system's refrigerant flows through them.
The failure of a reversing valve can cause the system to stick
in the heating or cooling mode. At times, the valve may fail in an
intermediate position resulting in the system not working.
Any debris in the system can cause the reversing valve to
fail. Also, normal wear of other components in the refrigerant system,
or the failure of a compressor or other device, can cause the reversing
valve to fail. Back To Top
Restrictions
A Restriction, or blockage, in the refrigerant system of a air conditioning unit
can come in varying degrees. Screens, strainers or filters in the
refrigerant system are installed in an effort to trap debris and
prevent the failure of various components. However, large amounts of
debris can result in a restriction, reducing the refrigerant flow
through the system. A slight restriction may result in decreased
performance. A larger restriction can result in the system not cooling
or heating at all. Back To Top
Indoor Coil
An Indoor Coil is a heat transfer device. The indoor coil absorbs the
heat from the home's indoor air, and passes it to the
system's refrigerant, which is then pumped outside.
As the air passes across the coil, any airborne dust or lint
that collects on the coil reduces its ability to perform. Also, to
provide the highest level of heat transfer, the metal used is extremely
thin. Airborne chemicals, detergents and cleaners can start corrosion,
resulting in leaks.
A coil in need of cleaning may have lower performance, or can
ice up from the low airflow. A leaking indoor coil may operate for
weeks, or even months, depending on the leak rate, but should be
repaired or replaced to prevent further, more costly, damage. Leaks can
occur in such locations that an attempted repair is not practical, and
the entire unit may need to be replaced. Back To Top
Outdoor Coil
An Outdoor Coil is a heat transfer device. The outdoor coil draws the
outdoor air across the coil to absorb the heat from the
refrigerant.
An outdoor coil should be cleaned periodically. Any dirt and
dust in the air can be trapped on the coil and restrict its airflow and
reduce its performance. They can also develop leaks from the constant
vibration of the compressor, weakening the solder joints and tubing.
The refrigerant is under very high pressures in the outdoor coil and
even the smallest leak can result in a complete loss of the refrigerant
charge. Any dirt and debris in the coil can increase these pressures
straining the coil's integrity. Back To Top
Drain Lines
Drain Lines allow your air conditioning system to drain off the water it has
condensed from the air. Over time the drain line can become blocked and
cause the drain pan in the unit to overflow. Dust and dirt from the
indoor coil can be washed into the drain line, where it settles and
causes blockage. Unlike the failure of most other items in the system,
a drain line failure can result in expensive water damage repairs.
Drain lines rarely give warning prior to becoming blocked and should be cleared annually. Back To Top