Thermostat clicks but furnace will not start.

 The thermostat clicks , The furnace starts that little fan on top then nothing. The ignitor will not come on, no flames, no blower. Resolved this today in Locust Grove by cleaning the pressure switch and draft motor then 24v gets to the board to start the ignitor. I can help you too Henry County. This took 45 minutes to get going again. Would have been faster but the furnace was hard to reach.