When your fryer goes down you probably want to get it up and running again fast. Fortunately, commercial fryers are generally easy to fix, and parts are also pretty easy to come by. There are four fryer parts that most commonly cause a fryer to fail:
BE SURE TO TURN OFF THE POWER AND/OR GAS FIRST!
How to determine what the problem is:
1. If the pilot light will not stay lit, one of three things have failed. First, check to see if the hi-limit is the culprit by taking one wire off and connecting it with the other wire. Do as you always do and light the pilot. If the pilot remains lit, then the high limit is bad and needs to be replaced.
To replace the hi-limit, you first need to empty the oil from the tank. This needs to be done because the sensing bulb for the hi-limit enters through the side of the tank. There is a large nut in the side of the tank and a smaller nut inside the large nut, loosen and pull these off. Now you can remove the defective high limit. Reverse the procedure to install the new hi-limit. Always screw the larger nut into the tank first and then the smaller nut. Light the pilot and your unit should be working.
2. If the pilot still will not stay lit, then the thermopile is most likely the culprit. One end is attached to the pilot and the other is attached to the gas valve. Remove the thermopile from both places and replace. Light the pilot, and if it remains lit you are good to go. Also, remember to reconnect the hi-limit wire.
3. If the pilot still will not stay lit, then the only thing left is the combination safety gas valve. To replace the combo valve, you will need to have a couple of pipe wrenches. This is the most difficult part to change, due to the limited space. Remember to install the new gas valve in the same direction and replace all the connections.
4. If the pilot is lit, but the fryer still does not work, the thermostat may be faulty. Only three things can happen, either the burner will not light when turned on even though the pilot is lit, the oil will not get hot enough or when the oil reaches temperature it will not shut off. In either case the thermostat will need to be replaced.
If it is running wild (will not shut off) the oil will overheat causing the hi-limit to trip out and shut everything off. By resetting the hi-limit and relighting the pilot and it stays lit, then you will know that the thermostat is not good. To replace the thermostat follow the same instructions for replacing the hi-limit.