Ceiling fan troubleshooting
This FAQ hopes to be able to provide some help to most
users with ceiling fan problems. It covers mostly everything,
and more FAQs are coming courtesy of Dan "Spiffy" Neuman.
Thanks Dan!
Basic Troubleshooting
1. Fan is not working
2. Fan light is not working
3. Fan runs, but wobbles or shakes
4. Fan runs, but slowly
5. Fan makes mechanical noise while running
i.e. clicking, knocking, grinding.
6. Fan makes a humming noise while
running.
7. Fan makes an electrical buzzing noise
while running.
8. Fan moves very little air.
I. Fan is not working
First, check to make sure that all controls on the fan
are functional and set properly. The pullchain should
be set to an operating speed (i.e. high), some fans
have a speed knob or the like. If the fan has a reverse
switch, be sure it it is seated fully in the 'up' or
'down' position. If the fan has a remote, make sure
it has a good battery securely in place. If the fan
has a more unique or unusual control system you may
need to ask more specific questions (see our
forums).
Does the fan have a light? Does the light work? If both
the fan and the light are not working, it is likely
a connection issue. Lower the fan canopy and/or housing,
and check to see that all the wires are connected (see
our wiring section for proper connections). Check to
see that there is indeed power from the supply-- there
could be a switch or breaker off, or a connection issue
within the wiring. Lastly, open the switch housing to
the fan and check that the white wire is connected to
both the light kit and fan electronics.
If the light is working and the fan is not, the first
thing to check is if the black wire has come disconnected
inside the canopy. If it is connected, what is it connected
to? Sometimes the fan motor is on a separate circuit
that may not be energized. Check also in the switch
housing to see that no wires are loose or disconnected.
Next, check to be sure that the blades turn freely.
If they do not, the problem may involve stuck bearings
(see 'oiling' section), a broken flywheel (see 'flywheel'
section), or simply something stuck in the path of the
motor or blades that does not belong there.
If the fan does not have a light, any of the above options
are applicable. The red, blue, or black/white striped
wire in the canopy and switch housing need not be connected
as it is for an added light assembly.
II. Fan light is not working
If the fan is working but the light is not, the problem
is usually a loose connection between the power source
and the light kit. Make sure the red/blue/black & white
striped wire is connected inside the canopy to the power
source, and inside the switch housing to the light kit's
black wire. The light kit's white wire should be connected
to the white wire(s) inside the switch housing. Check
also that the light kit's pullchain is functional. It
is also possible that the fan's light is connected to
a separate circuit from the fan motor, in which case
the red/blue/black & white striped wire would be connected
to a separate hot wire inside the fan canopy.
III. Fan runs, but wobbles or shakes
See section on balancing.
IV. Fan runs, but slowly.
First, check to see that the fan blades turn freely
by hand and coast after being spun. If rotation is in
any way stiff, this is a sign of dirty, dry, or gummed
bearings, which can slow the motor. Sometimes the bearings
can become tight and binding which can also be an issue.
See 'oiling'.
Second, does the fan wobble at all? If for any reason
the blade pitch is steeper on one or more blades than
the motor is designed for, this will slow the motor.
This can often be the cause of warping, or a blade being
knocked off balance. This will also cause the fan to
wobble or shake. See the section on balancing. You can
bend the blades to a shallower pitch if they appear
to be too steep, but be extremely careful as blade brackets
can break easily.
Most ceiling fans made in recent years use permanent
split capacitor motors, as they are efficient and reliable.
However with age capacitors can drift in value. If the
blades turn freely and are balanced, the cause of a
fan running slowly is almost always a bad capacitor.
The capacitor is a small black box or silver cannister
with two or more wires attached, and is located inside
the switch housing, motor housing, or inside a bell
on top of the motor. It should be replaced with a capacitor
of equal value, they are marked i.e. 6uf, 4uf, etc.
Some fans have capacitors with two or more values, they
should be replaced with the equivalent of those values
by one or more capacitors. More in the 'capacitor section'.
V. Fan makes mechanical noise while
running i.e. clicking, knocking, grinding.
If it's a mechanical sound, chances are it is a mechanical
problem. It could be something as simple as a wire that
has slipped into the path of some moving parts.
First, does the fan wobble? If so, balance the fan (see
the balancing section) and see if the noise persists.
Often times a shaking fan will allow some loose part
(such as a wire nut) to hit against a metal housing
piece. Balancing the fan may silence the noise.
If the fan is balanced, the next thing to check is if
anything is coming into the path of the blades or any
other noticable moving part. Remove the blades. Run
the fan motor. Does the noise persist? If not, the problem
is something coming into contact with the blades.
Assuming the noise persists, open up the motor housing
and rotate the motor slowly by hand. Observe where in
it's path of rotation and at which point the noise occurs.
Look also for any objects, such as a loose wire or wire
nut, coming into contact with the rotor.
If the noise appears to be internal to the motor, it
is most likely a bearing issue. Does the motor rotate
smoothly? You may notice a catch in the movement as
the noise occurs, or the noise may be fairly constant.
Dry bearings can also make a grinding, squeeling, or
rattling noise. See the section on 'oiling'.
Additional note: sometimes mechanical noises are the
result of loose parts on the fan. Check the blades,
blade brackets, light kit glass, etc, to be sure all
the screws are tight.
VI. Fan makes a humming noise while
running
In the case of noise complaints by fan owners, the vast
majority encompass a humming noise when the fan motor
is running. This is because all motors create vibration,
and the humming sound you hear is that vibration being
amplified by the fan housing, wood blades, even the
structure the fan is mounted to. The key to a quiet
fan is to isolate the motor vibration from all other
parts. This occurs, in the majority of fans, in three
places: between the motor and the blade brackets, between
the blade brackets and the blades, and between the downrod/motor
flange and the mounting bracket. Some fans also have
vibration-isolating material between the mounting bracket
and the ceiling.
On more expensive fans, a rubber flywheel is used to
attach the blade brackets to the motor. This is extremely
effective in dampening all vibration from the blades,
and no additional isolating material is required on
the blades. The downside is, especially in older designs,
these rubber flywheels disintegrate and break with age.
See the flywheel section for more information. On less
expensive fans, rubber or paper spacers are used between
the blade brackets and the motor.
Some fans, especially those that lack rubber flywheels,
have rubber or paper washers between the blades and
the blade brackets. This also helps dampen the transfer
of vibration to the blades.
The most consistent place for vibration isolating material
is attached to the mounting bracket. These days, most
downrod fans mount with a ball-and-socket type bracket,
and the ball, attached to the downrod, is usually made
of rubber. Some industrial fans, as well as older fans,
use a rubber grommit or grommits attached to a j-hook
or other mounting bracket. On hugger-type fans there
is usually a rubber washer or washers between the motor
flange and the mounting bracket. Lastly, some fans have
rubber spacers between the mounting bracket and the
ceiling.
If your fan makes a noticable humming noise, inspect
it for the above mentioned types of vibration-isolating
material. With the exception of the rubber flywheel,
if your fan is lacking any of the above, they are easy
to add and should solve the majority of humming problems.
You can always add additional material as rubber washers
and spacers are readily available.
VII. Fan makes an electrical buzzing
noise while running.
By far the most common cause of an electrical noise
from a fan is the use of an improper speed control.
Most fans made today, especially those with imported
16 pole motors (see 'quality/motor info' section) are
not designed to be used with Solid State speed controls.
Solid State speed controls induce noise on the AC line
(spikes in the wave form) that are amplified by the
motor windings. Use a speed control, such as a capacitor
type, that is recommended for your fan. Do NOT use a
dimmer switch EVER on a fan motor. See 'controls section'
for more details.
Some older fans, particularly those made in America,
ARE designed to be used with Solid State speed controls,
and may even have one built in. However over time the
insulation on the motor windings of these fans can break
down, causing them to buzz. The only solution to this
problem is to take apart the motor and varnish the windings
(not an easy task for most) or replace the control with
a quieter type (if the Solid State control is built
into the fan, again, not an easy task for most).
VIII. Fan moves very little air.
First, check and see if any of the other problems listed
above apply. Running too slow? Off balance? Check and
make sure the fan isn't operating in reverse (for most
fans, clockwise, see 'reversing section'). Another,
less likely, option is that the blades became bent or
warped without actually putting the fan out of balance.
If they became pitched too steeply that would also slow
the fan, see above. But if the blades became warped
or bent to a shallower pitch, that would not decrease
the motor speed but would decrease the airflow. Observe
the fan from the side to see if the blades are still
pitched noticably. If not, reference the balancing section for bending them back into place.
Lastly, you might just have a cheap fan that doesnt
move a lot of air. Peruse this site, and buy a new one!
Copyright © 2005 Dan Neuman
For more questions related to ceiling fans, please
see our general ceiling
fan FAQ page.
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