I have a Lennox electric forced hot air furnace, the model number is I believe CB29M-21126-IP.

What happens is (and this is only sometimes) the thermostat clicks on and it starts to blow air but it never clicks on the heat, it just blows coldish air. If I go to the thermostat and turn it off and go to the unit itself and reset the breakers and turn it all back on it works just fine. I have replaced the thermostat twice and that did not fix it.

Would anyone have any idea what could be the issue here?