Good afternoon Steve!
The answer may depend a bit on what you mean by 'stops heating'.
- One interpretation could be 'the heating shuts off, and the oven goes back toward room temperature
- The other would be that it heats up, but it heats to a certain temp and then stays there. it's just not as hot as it's supposed to be.
If it's the former, that sounds like something is overheating and an interlock is engaging because it's interpreted as 'I'm too hot where I shouldn't be, and I should shut off before I cause a fire. I'd leave that to a better trained service tech.
If it's the latter, then it'll depend on how low it is. If it's way low, then there's a couple possibilities:
- The heater element is defective, and even at the full current draw the oven can run, it can't get any hotter than that upper temp. This would mean replacing the element.
- The temperature sensor in the oven is defective or mis-mounted. There should be a temp sensor inside the oven cavity. if it's disconnected, or, say, bent out of place and much nearer the bake element then it should be, then the heat coming direct off of the element may be fooling it into thinking the oven is hotter than it really is. this could mean replacing the temp sensor, or just re-mounting it to proper position.
If it's just a bit low, then there could just be a calibration problem. If you look at the manual here
DCS WOS 127 Use And Care Manual Child Safety User Option
you can see how to adjust the calibration up or down in temperature to, hopefully, match the oven thermometer you're trying to use as a check.
Hope this helps!