I have a 1 year old Payne gas heat and air unit, model #py3pna024060ab. First time this year I tried to turn heat on and is not working. AC works fine, fuses tested good, and I believe the thermostat is o.k.; when I turn on heat the unit makes a fan noise and I hear a clicking about every 30 seconds. It sounds just like the igniter on a gas grill. Really don't want to call someone out. Thanks for any advice.