Here are the details you need to fix your whole house fan if it has the misalignment noted below. This information is offered at no cost by Invisco as a public service. The fix requires that you buy aluminum tubing, cut it into two pieces to a specific length and then drill two holes in each piece. If you prefer to avoid that work, you are welcome to purchase the finished kit from Invisco. See the bottom of this page to learn how.

Invisco purchased a new in box GAF LL Building Products 30BWHFS Whole House Fan from Home Depot in Temecula on March 18, 2012.

It was found that LL Building Products assembled the machine in such a way that the motor pulley and the larger fan pulley cannot be aligned properly without modifying the assembly in some way.

It was found that the larger fan pulley has been put on the shaft backwards so that it cannot be moved to correct alignment with the motor pulley. The motor shaft is shorter than it should be so the pulley on the motor does not line up with the larger fan pulley.

There are several solutions to this problem:

1. Loosen the motor pulley and move it out so it is in line with the fan pulley. This is NOT recommended because the pulley hangs too far out on the shaft. AND note that the engineering manager at LL Building Products is on record saying that GAF will not warranty the unit if this is done.

2. Remove the fan shaft and turn the pulley around. This involves removal of the fan from the shaft, then loosening the 4 set screws on the 2 bearing sheaves, then loosening the motor pulley set screw. The shaft can then be pulled out and the larger fan pulley can be turned over. There is a stop ring attached to one end of the shaft that makes reassembly very easy. However, all of this introduces the risk that the reassembly might not be done to factory standards. This is also not recommended.

3. Make your own repair kit. The parts you need to make are easy to make if you can cut aluminum tubing and drill holes in it. Specifically, you need two pieces of 1 inch by 1 inch by 1/8 wall square aluminum tubing cut to 4 and 5/8 inches in length. You then need to drill two holes in each piece that are 3 and 5/8 inches apart through both sides of the tubing. Those holes should be 9/64 inches in diameter so that 1/4-20 bolts will slide through the holes. You need to purchase 4 (four) 1/4-20 by 1-1/2 inch long hex head bolts and 4 self locking 1/4-20 nuts. The tubes are placed between the motor braces and the motor mounting plate as shown below. The longer bolts are used to hold the plate to the braces.

4. Purchase the Invisco repair kit. This kit comes with the aluminum tubing spacers cut to length and drilled and it comes with the longer bolts to enable the motor plate to be placed closer to the fan blade and the pulleys can then be aligned perfectly. The adjusting slots work exactly as they are designed. The only additional tool that is needed is a hex wrench for the motor pulley set screw. That tool is included in the Invisco kit. The total price for the kit is $9 plus shipping and handling. To get your kit shipped asap, simply PayPal $14.95 to kurt@invisco.com and include your address  or call us. 888-470-7374. Refer to the “GAF LL 30 Fix Kit”.

Original build out of box

Motor pulley moved out on shaft 1/2 inch - This is NOT recommended

Pulleys aligned with Fix Kit. Note the motor mounting plate is now on the underside of the braces using the aluminum tubing spacers and longer bolts in the kit. Note also that the motor pulley has been placed closer to the motor to align perfectly with the larger fan pulley. This is the ideal fix for the assembly and eliminates the task of changing the fan pulley.