Motors can go out. Pull off the grease screen and look and see if you can see the motor. Turn it on and look and listen. Give it a spin, one way then another. See if there is a grease buildup on the blades. Too much and it kills the motor.

No grease on the blades whatsoever -- I did check that. Looks like new.

It doesnt turn it on -- neither the fan nor the lights work.

Are these plugs regular power plugs? If so, you might use an extension cord and try powering the fan directly; if it works then the hood switch may need replacement.

kas

Not sure kas. There is a thin, flexible metal baffle that runs along the inside front of the hood. It has 2 electrical connections in it that run from back to front. One is a female 3-prong connector (shown below).

The other is a 2-prong male connector. I assume that one powers the halogens and the other powers the fan.

I went up there again and disconnected and reconnected both plugs although both were securely in place yesterday. Here is the male one that was loose last time.

Both connectors looked Ok but this is not an area of knowledge for me so I was looking for something blackened. Nada.

Now the hood has power again. The fan works but only 1 halogen works. It is easily replaced.

Would an appliance halogen burning out be enough to trip the power supply to the hood? And if so, could there be a short somewhere?

Should add the hood is 10. Viking can come out to look at it but it's expensive so I'd love to know what to ask them to look for. If the hood is working there seems little point in a service all. OTOH, I don't want to overlook something and have a fire or outage IYKWIM

Because you have no lights or fan - it sounds like there is no power to the hood. There is junction box in that hood that connects power to the hood. You need to test for 120 volts for the power coming in.

One poster had the good idea to plug the fan into an extension cord.

Turns out, the electrician who did our reno did not put the hood on a separate circuit. So that needs to happen. Then Viking will come out and replace the controller switch for the lights, which may be shorting out.

With all the complaints about Viking service, and the fact that they don't do tech support over the phone, I was able to determine this by talking to one of their tech people. Initiative is always a beautiful thing. Saves an unnecessary/costly service call until the root cause can be sorted.

I was able to restore power to the hood. But it evidently shouldn't be running on the same circuit as the electric cooktop and adjacent receptables.

"But it evidently shouldn't be running on the same circuit as the electric cooktop and adjacent receptables (sic). "

an electric cooktop would be 220v. You would not be running the hood on that unless you like excessive smoke, sparks and burning rubber smells. If you have a gas cooktop, then it would be a 120v circuit.

For the most part, the counter top 120v 20amp circuits are not to be used by anything else. The two exceptions I'm aware of are a receptacle for a gas cooktop/stove and a clock.

An exhaust fan is one of those items (like a microwave and the fridge) that can be on a separate circuit. It is advisable that the fan use a 20 amp circuit (or be wired for it) since at some point in the future it might be replaced by an OTR microwave which would need it.

Those certainly look like power plugs for 120 Vac circuits. If the fan housing label concurs with that voltage, then they could be plugged into an extension cord for testing.

Agree that the hood should be on its own circuit. This is easier said than done once the walls are closed up.

If a range is 240 Vac but wired with a neutral, then tapping one phase to neutral for the hood can work, but does not comply with code as I understand it. For one thing, the high current protection for the range is too much for the lower current rated wiring that would go to the hood.

kas

The hood is working again. One of the halogens blew, which seemed to knock it out. When I unplugged and repluged then put in a new bulb, it worked. But, this is the second time this year so something's up. After it started working again I thought I might be making too much of a production.

So Kas, thanks. You've made me feel better since I have the electrician coming on Tues to put it on a separate circuit. I don't think the original wiring was well balanced and the reno didn't address that.