No power to fan

It could be a bad connection or corrosion on the wiring connectors. I would suggest that you unplug the electrical cord to inspect the fan motor connectors, they should be tight and free of debris. If you had a meter you could check for voltage at fan motor but would have to plug in to power to do so so be very careful not to touch other contacts while performing the check. If you are not comfortable or experienced with electrical work I suggest that you take the unit in for repair or buy a new unit which may be best depending on the age of the unit. The fan motor is likely bad or it could be a switch./Difficult to say without properly diagnosing.

you should only have power on the black wire into the switch. The white wire feeds straight through. the switch breaks the black and routes it to one of the three outputs for the motor.

See if the motor is bound up. Move the fan blade to check for stiffness. The motor may just need a drop of oil. There is an internal fuse in the motor that you cannot change It may have opened. If you have access to a volt meter check all the wires on the power switch

Sometimes if a lot of steam has been produced while cooking, water may collect under the turntable plate and run down the spindle into the turntable motor. This can short circuit the motor and it will take the fuse out with it.
The fuse is usually housed in a plastic tubular case about 2inches long. Split the tube apart and replace the fuse if necessary (it's something silly like about 7000 volts). Switch on and check to see if anything else is not working like the turntable, lights, or fan etc and replace as necessary.

As far as oiling the fan motor shaft use a light weight lubricating oil like sewing machine oil. Just a drop or two will do. Olive oil is great for cooking, but to heavy a viscosity to be used for a lubricant. The switch should be in the "O" position.

I believe you are right.

there may be a problem with fan motor,but i believe your problem may be the rotory switch that controlls voltage to fan motor,to check this pull knobs off front ,then remove filter from back,there are 4 screws in bottom of case remove these,pull unit out carefully .there are 5 wires conected to unit ,two for fan 2 for on off switch,1 for ground just what wires go were,then disconnect wires from there posts,and pull unit out of box,find the two wires that go fan,snip wires that go to the circiut board leaving enough space to rewire after test get extention cord and snip off to make direct plug to fan to wall connect extention to the two wires from the fan motor and wire nut or tape so no short,pug extention cord into wall outlet if fan runs on a high rpm or max power,then your rotory switch is no good and you can install an external rotory switch on side of unit,if fan does not run any faster then your fan motor needs replaced,let me no if you need more help

You need to replace the power supply of the unit, Contact your heating and cooling contractor for service on the unit.

take out the cells, they weigh about 8 pounds apiece. Make sure you remove both. Put the door back on and turn the fan in the furnace on. IF the light on the power supply comes on, then the power head is most likely good.

Then insert one cell at a time, individually. Push the single cell in all the way to the back, put the door back on, if the light is on, that cell is fine. If the cell does not come on, there is most likely a bent fin on the cell. simply bend the fin so it does not touch the other fins and you should be fine. Repeat this step on the other cell.

Make sure the door to the filter is closed, the power switch is on and the furnace fan is on.

Good luck.

Hello night light,

How you proceed is going to depend on how comfortable you are taking it apart.

Given it's age and purchase condition, warranty isn't an issue. You will either be able to dis-assemble the purifier and try taking the motor apart and reassembling, or you can find a replacement motor (I've seen some on the web, they start at ~$50).

Another possibility is that the fan pot (the rotary switch that the knob turns to adjust the fan speed) may be out. If you have a multi-meter, see if you can get a signal through (when it's all the way open). If not, try replacing that first. Parts are available onthe web, I can't advertise per FixYa's terms of use.

Hope this helps.