The Fan Speed Fluctuates on My Amana Air Handler

Variable Speed

• Before assuming something is wrong with your furnace, take a look at the type of Amana furnace you have. Some Amana air handlers, such as the AEPF versions, are variable speed. This means that the fan speed is designed to change. The DC motor these systems use operates at different speeds to increase efficiency and ensure no power is wasted as the furnace starts to heat up. A variable speed fan fluctuates as part of expected operation.

Motor

• If you do not have a variable speed Amana air handler, changes in fan speed can indicate wear and tear. The motor is a likely source. As the fan motor starts to wear down, it may stall, run roughly, suddenly slow down or briefly stop. These are signs that the motor is dying or its wiring is malfunctioning. Either way, replacing the motor may be a necessary step to fix the problem.

Fan Issues

• If the motor runs effectively but the air speed still seems to change, check the fan itself. Dirt and debris can cause varying speeds if the fan has not been cleaned. Damage or warping may also affect the speed at which the fan operates. If the fan belt is old, it may be reaching the end of its life. If the belt slips or loses traction, fan speed will randomly change.

Efficiency

• If there is no evident cause of the fan speed fluctuation, broaden your search. Check your air filter to see if it has unexpectedly clogged and needs to be cleaned or replaced. Examine your evaporator coils for ice or grime build-up that may impair efficiency. Test your thermostat and its sensors to see if they are turning the fan on and off randomly because of electrical problems.