Cannot turn off fan

The correct model number is located on the appliance data plate. It's usually located on the door jamb (built-in) or back or bottom (for a countertop unit). Sears uses a 123.456789123456 type of designation (where the first three numbers/letters are the manufacturer. The data plate will clearly state "Model" followed by the number.

Fan works when component heat is higher so its normal.

The model number 721.80032 is a partial model number; it indicates the build series. I found the Kenmore microwave, 721.80032700. The final 3 digits indicate the panel color and similar details.

Assuming the microwave was installed properly, it should work as a hood fan. Press the touch pad with the fan icon (underneath it says Hi/Low/Off) to get the desired fan speed. The icon is on the lower left of the control panel; it's below the Cook Time button and to the left of the Light button.

The manual for the 721.80032700 is available here: https://www.searspartsdirect.com/partsdirect/user-manuals/72180032700-kenmore-parts-manual?manualIndex=0 . The direct link to the Owner's Manual is https://c.searspartsdirect.com/mmh/pd_download/lis_pdf/OWNM/L0710653.pdf . See pages 9 and 14 for using the exhaust fan.

I hope this helps.

Cindy Wells

Actually, that's a feature! If you cook much on the range (stove) beneath the microwave, the heat will cause the microwave bottom to heat up quite a bit (just touch it!), and the microwave will turn on it's exhaust fan in an attempt to save itself from burning up. It will shut off in about 15 minutes after you turn off the source of heat.
But if the fan comes on by itself even when the microwave is cool (or at least not hot), then you probably have a defective fan thermostat. This thermostat is located behind the control console on the inside bottom of the microwave.

If you need further help, reach me via phone at https://www.6ya.com/expert/ronald_e6b9572cebe3ad27

You probably have a bad fan thermostat. This thermostat is supposed to turn on the vent fan if the microwave oven gets too hot (caused by cooking too much or having too many burners turned on on the range beneath the microwave oven). It should shut off in about 15 minutes after your turn off the range burners. But if it comes on for no reason, or won't turn off, then You probably have a bad fan thermostat.

If you need further help, reach me via phone at https://www.6ya.com/expert/ronald_e6b9572cebe3ad27

Most over-the-range (OTR) microwave ovens have the exhaust fan funning at low speed when the microwave oven is working. This is to keep the magnetron and electronics cool. And it sucks air in from the bottom, so if you just place this microwave flat on the countertop, it won't be able to suck air in, and it could overheat if you use it for more than just a few minutes. But if you can put it on some boards or some sort of grill so air can get to the bottom, then you should be okay to use it as a counter-top model.

If you need further help, reach me via phone at https://www.6ya.com/expert/ronald_e6b9572cebe3ad27

Hi,
Here is a tip that will help you to figure out what is wrong with yourMicrowave Oven....

Microwave Oven Basic Troubleshooting Tips

heatman101

sytjhf

Assuming your fans are working, this may be a magnetron on its way out.

If it's within the 1-year warranty, I'd call Sears for service right away.

Otherwise, I wouldn't leave it alone while running, just to be safe.

We're happy to help and we appreciate your thoughtful rating of our answer.

The problem is likely on the control panel, which we repair nationwide for $39.95 postpaid.

This light failure often occurs when a bulb goes out and the filament shorts, or when the bulbs are removed or installed without first unplugging the oven from the power line. Either can cause such a failure on the controller.

This often can affect the exhaust fan operation, too. The lights and fan can be inopoerable or stuck on.

If you or a friend decide to look into it, we have critical safety information, info on door switch diagnosis and replacement, and

disassembly information at our site, linked here on Fixya: http://tinyurl.com/yzjozk

"Microhood" seems to be a slang term for the "microwave hood" (hood fan or exhaust fan) which is normally part of an over-the-range microwave oven or range. But these should be available separately, as I seem to recall. I would contact home centers such as Lowe's, Home Depot (if they still exist), etc., or a local appliance store.