Hi - I’m new to this site. I’m looking for advice/help in fixing my thermador downdraft exhaust fan. Model # CVS36RS/01. I push the on button to raise the unit and it starts a never ending cycle of up, down, up, down. I had to unplug it to get it to stop. The fan controls still work properly. Is there some kind of sensor that can go bad? Broken part? Please help.
thanks,
chris
I have the same problem - unit goes up and down until manually switched off with the stop start button. The unit also makes a whinning noise when the blower is operated. Any help would be appreciated.
Down, behind the motor there are two switches, on of which is the vent switch and the other is the gear motor switch. The gear motor switch is what cuts power to teh motor when the snorkel is fully up or down. Two things can cause the snorkel assembly to continuously raise and lower, and they are a) the drive arm has backed off of the drive shaft and, therefore, is no longer making contact / aligned with the gear motor switch, or b) the gear motor switch is broken.
Attached is the service manual for the CVS units.
KC
cvs_service_manual.pdf (521.9 KB)
My downdarft vent also raises and lowers with 0ut stopping. I have to unplug the vent to get it to stop. Dacor said it was the snorkel (up and down switch)? Any other suggestions?
I’m not familiar with this model, but I imagine it would have a some sort of limit switch that will stop in when it reaches its highest and lowest points. I tried to find a wire diagram, but was unsuccessful. If somebody has one to post, I can look at it and, probably, diagnose the problem.
When I called Dacor they said it was probably the up/down switch. After looking at the diagram on the unit, I dont think it is the up/ down switch.
Dacor gave me a appliance parts company in Sacramento to call. They charge $70 for a 120v/5 amp switch! I found one at an electonic store with more amperage capacity but it would not be an exact fit. There price was $7.50! Thanks for your help.
Thank you for posting the user manual. The snorkel on my Thermador downdraft vent will not go up or down, and is currently stuck in the down position. I am guessing that the switch is the problem The troubleshooting section of the user manual suggests using an ohmmeter to check continuity, however, to access the switch wiring, the snorkel must be up (I believe). Any idea as to how to deal with this situation? Thanks.
Most likely you have to raise the snorkel manually.
Gene.
Thanks. Can you please provide advice as to how to raise it manually? I’ve tried simply pulling up on the top of the snorkel, but it won’t move. Is there a way to make this happen from underneath the cook-top?
The gear motor switch wires can be accessed for test from the motor side. Also check the up/down switch and the motor winding.
Gene.
Our Thermador downdraft didn’t want to pop up when you pressed the button. It did this on and off for a few months, then stopped working completely. Mind you, if you pulled up in the middle of the downdraft and lifted it up a few inches, after pushing the button, then the motor would help lift it the rest of the way.
Anyway, we replaced the gear motor switch and now it’s working properly again. Here’s the switch that fixed the problem:
BOSCH Switch, micro
Servicer in post #3 was on the right track (thanks).
If it goes up and down and won’t stop or the fan won’t go on it is most likely that the piece that goes on the motor shaft has wriggled off the shaft enough so that the raised flange on that piece no longer contacts the switch.
The easiest thing to do is to remove the lower left panel with the unit down and disconnected from electricity. You can reach up to the other side of the motor and try to push what you can feel back toward you onto the motor shaft. Then plug everything back in and try it. If that doesn’t work then you may have to proceed with disassembly to get to the switches. But if the starting problem was “goes up and down without stopping and no fan” then this is the likely fix.
On the right side of the motor, there is a little ratchet lever. If you press that in, then the snorkel will go down manually. Don’t do what I did and unscrew the gear motor arm to get the snorkel to go down. Just depress the right side of the motor, and the snorkel will go down. You can also manually trip the gear motor switch and the fan switch by reaching to the rear of the J-box. See page 2-5 in the manual. Chances are good that if you are having a problem getting the snorkel up and down, but the motor is working, you have a problem with the gear motor switch. While you have it all apart, just replace the vent switch, too. Also, if you are having problems getting the switch that raises and lowers the snorkel to work, chances are that you have screwed in the side screw too tightly, (that holds the top cap on the snorkel). Loosen it a little an the switch will probably work.
Mine clunks down? Advice?
My CVS downdraft quit raising due to a badly bent linkage plate. The snorkel is down and the motor gear arm is not accessible. How can I get the motor gear arm down? Thanks, Jim