The oven and water heater wouldn't have anything to do with it
If it is electric, it's most likely the sequencer. I have then go bad all the time at work. It pretty much controls everything on an electric furnace. Most of the time they stick in the on position, so the residents call me and say their apartment is 90 degrees. Every now and then, they will stick in the off position, and they call when they get cold.
It's also possible the fan motor went out. The best way to tell is to turn on the furnace, and wait about 2 minutes. If it doesn't come on, reach in to where the fan is, and try to spin it by hand. If it starts working after you spin it, or if it turn really hard, it's time for a new one.
If the fan comes on, but it blows cold air, the heating element is bad.