Hi!What you need to check is the thermostats on the heating element itself. To do this, you will need an ohms meter. What you will need to do is remove the wires from the three thermostats. I suggest doing this one thermostat at a time, and also either taking pictures or drawing/writing everything on paper so you do not get confused as to which wires go where.If you look, there are always two wires across from each other. What you need to do is remove each wire and check the resistance from one terminal to the other directly accross from it. If you have no resistance, it is OK. If you have resistance, it is bad. Check this for all three thermostats.Have you checked your venting? You should have plenty of air coming out. If not, please clean them!If you have any questions, please post them here. If not, please click accept. If you are satisfied, please leave me feedback so that I know how I am doing. Thank you!