have electric forced air furnace, only blows cold air, have checked cir breakers.
This could be a control problem. Or a problem with the elements themselves.
To check the control circuit, often requires you to move a multimeters probes and or your hands close to the line voltage circuits, where a wrong contact with the probe could fry your control system, and or you.
If you can give a better idea of your abilities. You may get help. If your not comfortable with your hands being close to 240 volts. You may want a contractor to come out and diagnose and fix it for you.