Is your oven running into heat regulation trouble?
Many parts could be to blame but many owners and technicians will test the oven thermostat first. The thermostat reads the temperature inside the oven and acts as a switch to activate and deactivate the heating element according to the current temp.
Before you try to diagnose yourself, kill all power to your oven. Shut it off at the breaker panel or unplug it from the wall. The amount of electricity that can pass through and shock you is seriously fatal, so be extra careful here.
Next, figure out where your oven thermostat is located. The location will vary based on the specific oven model and manufacturer. You can find the location by referencing the owner's manual that came with your stove, or by looking online for a diagram.
Your first step is to conduct a continuity test with a multimeter on the thermostat switch. It's imperative to take out the specific wires that need to be checked. You'll need to check the wiring diagram for your oven to figure out which wires you need to test. Please also remember that you can only test a single pair of wires at once. If you don't know how to do this, watch videos first or leave the job to an oven repair expert instead.
If your multimeter fails to find continuity in any of the contacts, your oven will need a new thermostat to work properly. If it passes the continuity test, consider calibrating your oven as that might fix the temperature control issues you are facing. Your manual will also tell you how to this and most oven models will let you adjust by roughly 35 degrees, higher or lower.
Some oven problems will result in error codes if this is a feature that your oven offers. Check your LCD display to see what shows up and look up the code in your owner's manual. The oven error code can also be searched for online if you do not have a copy of the manual. From there, you will know either what the problem is or what part is causing the code to show up. This information is very useful for diagnosis purposes; most newer ovens offer this feature so do your research if yours does.