There’s a difference between a dead oven and an oven that heats but bakes wrong. If food comes out underdone, or the temperature feels off even after a full preheat, you’re not dealing with a total failure. You’re dealing with partial heat, and that narrows the cause to three parts: the bake element, the temperature sensor, or the control board. Here’s how to sort them out.
Three parts, three behaviors
The bake element is the coil across the bottom of the cavity. It doesn’t always die outright. It degrades. It still glows and makes heat, just not enough. A healthy element glows bright and even. One that’s dull orange, or bright in some spots and dark in others, is on its way out. That slow half-failure is common on older ranges and it’s easy to miss.
The temperature sensor is a thin probe, usually up on the back wall of the cavity. It tells the board what the real temperature is. When it drifts, the board acts on a lie. The display says 350 while the cavity sits at 300 or 400. This is the most common reason for the “oven works but nothing bakes right” complaint.
The control board is the least common of the three, but worth knowing. If it feeds power to the element unevenly, or misreads a sensor that’s actually fine, you get erratic heat. Board failures can mimic sensor failures, which is exactly why the order you test in matters.
How the diagnosis actually goes
First stop is the sensor’s resistance. Most standard oven sensors read about 1,080 to 1,100 ohms at room temperature, around 70 degrees. That holds across most brands, though a handful of models use sensors on a completely different scale, so the service data gets checked if a reading looks strange. Pull it, meter it, and if it’s way off the expected number, that’s usually the answer. It’s a clean swap.
If the sensor’s good, next is a real-world check with a separate oven thermometer. That tells you whether the sensor is lying to the board, or the board is getting good data and still doing something wrong.
The element gets metered too. A healthy bake element usually reads somewhere around 20 to 40 ohms depending on wattage. Open circuit means it’s dead. A reading that’s technically continuous while the element looks uneven can still mean degradation.
Only after sensor and element both test clean does the board come into focus, at which point it’s about voltage to the element during a live bake and whether the board is cycling it on and off at the right intervals.
What you can check without tools
Looking at the element costs nothing. Open the cold oven and study the coil. Cracks, blisters, burned spots, or a section that looks different from the rest are worth noting. If you’re booking a tech, mention what you saw.
That’s where safe homeowner inspection ends. The physical swap of an element or sensor isn’t hard. Having the right diagnosis is. A sensor that reads slightly off might still be in spec for that model. One that reads fine cold might drift under heat. Buy the wrong part on the wrong conclusion, install it, and the problem’s still there, except now you’ve bought a non-returnable component. Control boards alone run $60 to $350 or more depending on brand and model, and many are final sale once installed.
One free thing to try: calibration
Some ovens let you nudge the temperature calibration in the settings menu. If yours runs consistently a little cold or hot, check the manual for “oven temperature adjustment” before anything else. It won’t rescue a failing sensor or element, but if the offset is small and the hardware tests fine, it’s a no-cost fix.
When it’s tech work
If calibration doesn’t do it, or the offset is maxed and the oven’s still off, the next step needs a meter, the right resistance spec for your model, and voltage testing during a live bake. That’s a tech’s job.
Above all, don’t guess on the board. We’ve replaced plenty of $200-plus boards that homeowners bought when the real fault was a $30 sensor with a borderline reading. We confirm the root cause first, then tell you exactly what it needs. The $75 diagnostic gets credited to the repair.
We work across the Bay Area on most brands, often same or next day. Schedule a visit and we’ll diagnose it properly.