20 Most Recent Broan-NuTone ATTIC FAN THERMOSTAT CONTROL Questions & Answers

Hi. The most likly cause of this type problem is the thermostat. Check the thermostat housing is it hot to the touch, is it close to a heat soarse, suchas, a motor or flu pipe for a water heater. If the thermostat has a adjustable heat range setting try setting it to the lowest setting if this shuts the unit off the calibration of the unit may not be set right. If the unit is new this should be covered under warranty.

I just fixed a Broan-353 with a similar problem - the fan was short-cycling, turning on and off within a minute or less.

These fans have a thermostat which is designed to turn off 10 degrees below where it's set to turn on. Apparently, one failure mode is this temperature delta stops working I've had this happen twice, each time after about 3 years.

Replacement thermostats are available from Broan for about $30 http://parts.broan-nutone.com/broan/Shop It's a 10 minute repair if you have easy access to the fan.

The fan gets it's electricity from a fuse or breaker that probably also controls some other outlets or light sockets.

My experience is you need to use a flat head screw driver to seperate the top housing from the bottom. You will have a groove on each side that has to pop free before it slides out into two pieces.

Return for replacement or see if you can fix.

I'm looking for the replacement motor for Nutone 668N-part #53709000- it is discontinued. Central vacuum has a replacement buyt is out of stock. There is no new unit that fits the old opening. I have no ascess to the attic. Any ideas?

The motor is usually not repairable. You can sometimes purchase the motor and fan separate but that is about it. Here is a link to a blog about replacing motors.
http://nutoneproducts.blogspot.com/2009/05/broan-bath-fan-motor-replacement.html

faulty thermostat switch

Pull the cover from each side directly straight down. The cover will come down about 2 inches. Reach up on either side and squeeze together the spring to release it from the housing. The cover will swing down. Replace bulb. Squeeze the spring back together and initiate it into the housing. The last step is to push vertically the cover back up in to the housing.

Try adjusting the fan lower on motor shaft failing that buy another unit and change motor and return broken motor

It is cheaper to get a new unit than to attempt a repair.

try hoovering it get the dirt out and some wd40