If you do not need to test the hi-limit thermostat, skip this step.

This step requires a multimeter. If you aren't familiar with how to use one, here is a guide that will help you.

With the hi-limit thermostat disconnected, you can check it for continuity. It should show continuity (less than 1 Ω) at room temperature.

If it shows OL or anything above 1 Ω, replace it.