It will only heat to 350 degrees, but the gage goes up to 700 degrees. In other words, how high can you get the temperature to with all burners on high? Thanks, Ron

If your burner always heats to "high" when it's on--regardless of how you set the burner knob--the switch contacts are shorted closed. Check the circuit for any other grounds, then replace the switch.

There's a few things that can cause this.

1. Check to see if the both that Bake and Broil elements (burners) are heating up. Check the Broil element in Broil mode.

- during pre-heat the Broil element gets cycled on and off for short time durations to speed up the heating. If the Bake element is not working, then the oven will heat, but very slowly and never reach high temperature.

2. If the elements are both working, then it's possible that you have a bad temperature sensor.

- this is a temperature dependent resistance device that should measure 1080 ohms at 70 deg F (room temp).

3. If #1 and #2 are ok, then the problem is with your oven clock/control unit. We rebuild these at fixyourboard.com.

If your oven is 20 years old the temperature sensor system might no longer be accurate, if you have access to a temperature measuring device that can confirm that the oven is not reaching 350 then run it up and check that its not just your indicator light system. Some oven burners have air control and yours may have accumulated oven soil over the years. If your burner. Is behind a short wall like mine is, use a mirror and torch to check. A clean can bring things back to standard. Flame heat is from a good mix of. Gas and Air...

Since you've mention the pilot light goes out at 400 degree F, then we are talking a gas Deep Fryer. The deepfryer usually use at 350 degree F for chips or else. Because the oil will start breaking down its quantity of frying very quickly over that temperature. Most people set at 350 degree F. Now we comes back to your problem, First you should have a deep fryer thermometer they espcially made for deep fryer, (You only mention 400 or better ) that make me think you're only guessing. Knowing the temperature is very important, most Hi limit is set at 420 degree F.
To me it seen the Hi Ltd control is working and that is why it cutting out the pilot when it reach its limit but we don't know what temperature that when the hi limit cutting out at.
When you have a thermometer, put it in the cold oil and turn the temperature to 100 degree F to see what the temperature control cutting out at. slowly increase your setting until it cutting out at 350 degree F . If you set at 250 degree F and the thermometer already reaching 350 degreen F then don't go any further , your temperature control is defective and need to be change a new one.
This is only the first step, you still have to check out the Hi ltd control to see how good its condition is,so far your information say it cutting out at 400 or better. But you've to be sure, because it is a safety control. Hope that will help you , God Bless.

sounds like your thermostat is bad

The first thing I would check is the hi limit.If that not out then I would try to a temp. gauge that will read above 350 degrees.maybe the thermostats is not right. Reading to low for the temp.

Try to set it at 500 degrees and see if it goes off at 350. If it does, then it probably needs calibrating. You can calibrate it by taking the knob off and finding a set screw in the stem where the knob sits. If this is not the problem, you may have to replace the thermostat. By the way, check to see if your temperature probe is not touching the wall of the oven. It will give it a false reading. Let me know if any of these things work and we will go from there.

how do you know it is dropping 100 degrees ?
If the set temperature is 350-400 the heaters will work untill the thermostat will read that the temperature is reached - after that the heaters will shut down and the temperature will drop...and after few minutes when the temperature goes below thw set point (in this case 350-400) the heaters will turn on again - this will happen for the duration of the timing you have selected (example 45 minutes)

Often the temp gauge is the culprit. To check temps, allow to preheat for 15 minutes. Monitor the highest temp reached after burner shuts off and record. Then monitor lowest temp before burner cycles back on again. Average out readings. Example, if high is 355 and low is 345, average temp is 350. Do this for 3 cycles and average out.