Wall Heater Making Noise? Fan, Ticking, Clicks and Clunks

Sounds the makers call normal

The fan. Cadet says its fan-forced wall heaters are generally quieter than a regular refrigerator.

A fan that slows down or runs on. Cadet says its Energy Plus heater has a variable speed blower, and that a slower fan and lower heat output are normal once the room is at the set temperature. In its Night/Away mode, the fan runs at a low level for 5 to 10 minutes until the heater cools down.

A motor that runs slowly. On other wall heaters, Cadet says to make sure the supply voltage matches the heater’s rating and that the heater is clean. If it still runs slowly, the motor or heater may need servicing or replacing.

On a Rinnai gas wall furnace. Rinnai says its fan starts after a short delay once the burner lights, to let the heat exchanger warm up and avoid cold drafts, and keeps running after you turn the heater off until the heat exchanger cools. It says sharp clicking at ignition, or when the heater turns down or goes out, is expansion noise from the heat exchanger, and a clunk when the thermostat operates is the gas valves opening and closing.

An electric wall heater: clean the fan

Why. King says to clean an electric heater at least twice a year, and more often with pets or a lot of dust. Cadet says to clean its Com-Pak heaters as needed, or every six months at least, and its Energy Plus heaters at least every six months. Marley says owners of its Smart Series wall heater should only vacuum and wipe the outside and the grille openings, and leave cleaning inside to qualified service personnel.

King’s steps. Turn off the circuit and test it with a voltage detector. Take the thermostat knob off carefully before the grill, because forcing it can damage the thermostat. Blow the dust out with compressed air, or a low-velocity blower or vacuum, but never canned air, which King says can hold a flammable propellant. Keep the fan blades from spinning while you blow, because that can damage the motor.

Cadet’s Com-Pak steps. Cadet’s Com-Pak guide says to make sure the power is off and the element is cool, take the grill off and wash it in hot soapy water, then dry it. Hold the fan so it is not damaged or bent while you blow debris through the element with a hair dryer or a vacuum on blow, and vacuum the fan area without touching the elements.

Then listen. King says to put the grill back only when it is completely dry, turn the power back on, run the heater for a few minutes and listen that it sounds like it is running smoothly.

Do not oil it. Cadet says not to lubricate the motor, and King says its fan motor does not need lubrication.

An electric fan that will not spin

Stop using it. Cadet and King say not to run any heater after it malfunctions: turn the power off at the panel and have a qualified electrician inspect it before using it again.

What Cadet lists. Cadet’s Com-Pak chart says that if the element heats for a moment without the fan turning and then stops heating, the cause is a defective motor or internal connection, or a fan or motor that is jammed. For a defective motor or connection, the heater or fan motor needs replacing. For a jam, turn the power off at the breaker, let the element cool, remove the obstruction and reset the heater as its instructions describe; if it still does not run, it needs repair or replacement.

On an Energy Plus. Cadet’s chart says a fan or motor that does not spin is a defective motor or one out of alignment, and the fix is a new motor. Cadet says any service other than cleaning should be done by an authorized service representative.

When it keeps shutting off. King’s WHF manual says that if its thermal protector shuts the heater off again, turn it off at the breaker at once and look for a failed fan motor or dirt and lint on the element. If it keeps cycling the heater off, King says to disconnect the power and have a qualified electrician check and repair it. Cadet says a Com-Pak whose limit trips more than once a day must be replaced.

Check for a recall. CPSC says the fan on some Cadet Apex72 high wall heaters can fail to turn on, so the heater overheats and can catch fire inside, and that some old Cadet and Encore in-wall heaters could send flames, sparks or molten particles through the grill. See the Cadet recalls to check.

A Williams gas wall furnace: a noisy blower

Cleaning. Williams says to let the furnace cool and to shut off the electricity and the gas before working on it. Its care section for the Monterey Plus says that if it has the optional blower, clean any lint or dirt from the fan blades, the fan motor and the air passages you can see.

What else Williams lists. Its troubleshooting chart, which it marks as for qualified service technicians, gives three causes of a noisy blower: a rattling housing, a dirty blower and a bent blower wheel. The fixes are to tighten the blower screws, clean the blower wheel, or straighten or replace it.

Once a year. Williams recommends that a qualified service technician check the furnace at the start of each heating season.

On a Rinnai. Rinnai says all maintenance and service on its direct vent furnaces is for a qualified service technician.

A gas wall furnace: ticking as it heats

Normal clicks on a Rinnai. Rinnai says sharp clicks at ignition and when the heater turns down or goes out are the heat exchanger expanding.

When the casing is distorted. Williams’ chart lists expansion noise and ticking under abnormal operation. Its fix is to check the installation: the casing may be distorted by being fastened to an uneven opening or jammed under the header, and a restricted vent may create expansion noise. Williams says to make sure no part of the vent is blocked or rusted, and to clean or replace it before using the furnace.

The legs. Williams says the legs must sit flat on the floor plate, and never to raise the furnace up to meet the vent pipe.

On a Rinnai EX38C. Rinnai’s EX38C manual says not to cut the intake hose attached to the heater, because cutting it may result in noise.