Model #RV46S, this rather large telescoping downdraft vent was no longer moving up and down when the control button was pressed. The customer hadn’t noticed anything out of the ordinary and the last time it was raised to the operating position, the blower was functioning as expected. Now with it stuck in the down position, the blower doesn’t work so it’s not much good as a vent.
Vents are used to draw damp, Oder ridden air from cooking surfaces and moving it outside the home. They come in many different shapes and types as they are meant to be decorative as well as functional. Most units are simple in design in that they consist of only a few vent parts. These are generally a multi speed blower motor, lights to illuminate the cooking area, and control components to, well control everything. Others, like the one in this post, will also use motors and supporting components to raise and lower the upper portion to the operating position for use. As long as these parts are functioning, there really isn’t much that can really go wrong.
This vent was not raising, and since the components involved are few, I went straight to the control board to start my investigation. Most of these style vents, will use an electronic board, either mounted down under the cabinet, or in the upper portion to control the operation of the lift motor and blower motors. This board, along with one or more limit switches to determine the position of the top portion, are used to prevent the blower from operating unless it is open. It is the board and limit switches that directly control the lifting motor, so when the vent stops raising, we can limit our troubleshooting to one of these components.
Just to be safe, I raised the vent by hand (this can’t be done on all brands) to make sure nothing was blocking the vent. I then went to the control board to verify voltage to the board, and checked limit switch operation while I was there. The motor can also be checked from it’s board connection along with the up and down push button mounted to the top of the vent. Since each one of these components were checking out fine, this leaves the control board itself as the failed component.
With power off, a new control board was installed and each wire and connectors were put back in place. The power was turned back on, and the vent started to lift with the press of the button. Once in the upper position, the blower motor came on and started moving air. Another press of the button, turned the blower off and lowered the vent behind the cook top. The vent was fixed and working well again.