I was putting "bug bomb" in my basement and to be safe I flipped the switch in the breaker box off. When I turned it back on, the furnace has not come on. What can I check? I really need to NOT have to call someone for service.

Turn the breaker completely back off then back on. Make sure all circuit breakers are on. Make sure thermostat is calling for heat. If this fails something happened to your unit or the circuit breaker but I find that hard to believe since the chances of that happening are one in 100,000 or so.