Not having it in front of me makes a answer very difficult. But let’s at least give you some ideas.
Your unit is kind of like a combi-oven. It has two heating units, one for the water and one for the air. Both have separate probes to sense temperature. The controller determines if there is a call for heat to either one and energizes a contactor to heat the oven or water. Temp probes can easily be tested with a ohm meter.
Now be aware, that they have 4 different controllers. And you never stated power supply. How did you determine that it is too hot? With a calibrated temp probe I hope. Monitor the contractors to determine which is causing the overheat. Also check for drain valve leakage. When was the last time that the water system was cleaned? Is there a build-up in the tank. Is the blower running to speed?. Is the fan clean?
the unit is 240 fan running when we open the door there is a lot of stem checked it with a thermostat the unit it almost at two hundred degrees which for our application instead of holding the food it’s actually cooking it. It won’t hold for two long so we have to turn it off and after a 20 to 30 minutes we turn it back on. We try to clean it as often as we can No build up probes look clean what is the water probe and air probe resistance do you have any idea what I should be looking for? thank you for your input I thought no one would answer my question, thank you for taking time to do so. I really appreciate it.
Being you are going over temp with a lot of steam, I would be looking at the evaporator system. The air heater is only 950 watts, but the evaporator heater is about 1800. Check the float switch and probe to be clean from minerals. Any build up on the probe acts like a insulator. And if water gets below the probe, it’s accuracy goes out the window. I do not have a ohm chart for there probes, but if you call them, I’m sure they do and will probably share it. Alternately, with a cold unit the air probe and the water probe should have near the same resistance. While you are at it, make sure the float switch is functional. Sometimes the get crud inside and hang.