The heaters are always mounted in the base of the units and each unit is a little different to access.
We'll take a look at some examples here we have a mighty light speedster and Ltd now once you have located your heater the reset button if you need to reset it is right on the side and there are two sensors per heater casting your machine if it's a mighty light we'll have one heater casting if it's any other mighty machine it will have two heater castings.
You may see four sensors you may see two sensors depending on your unit of those sensors you always have one that is an automatic and one that is a backup.
If you ever have to reset always look for the sensor that has a button in it and that's a reset button now you may ask what causes the reset button to pop well really simply put it's if your automatic sensor fails think of your sensors as just switches they're constantly going on off on off allowing power to the heating element but after a while they'll fail.
To protect the heaters from melting down we put a backup sensor if that thing shuts off or pops you know that your first sensor your automatic sensor has failed needs to be replaced really easy to do it's a couple screws you pull off the wire you put on new one you put the wire back on really simple to replace them but it's important that you maintain your heaters.
Just remember that if your if your manual sensor pops it's supposed to do that but it means that your your automatic has failed and it needs to be replaced you.