It’s easier than you think!

When I got my new gas wall oven, I was excited. It baked things consistently, with no surprises. As time passed though, the results started changing. A roast that I used put in a 350° oven and bake for 30 minutes a pound was not coming out the same way. And that was a BAD thing—especially when I was cooking dinner for others.

My oven, once truthful, was now lying to me.

What to do?

The options:

1. Simply adapt recipes on the fly based on what seems to be the problem
2. Use an oven thermometer to see what the temperature really is and shift baking times accordingly
3. Rely solely on a food thermometer (some foods are more thermometer-friendly than others)
4. Be methodical, discover the true average temperature, and then calibrate it myself

After a brief stint of trying option 2, I’m currently at option 3 with an occasional option 1.

But honestly, I need to try option 4—especially with the holidays right around the corner. I’m tired of overdone this and underdone that. I’ve even been off by an hour when cooking turkey.

Before we get started, it should be noted that even new ovens can be off. Some are deliberately calibrated to run cool or hot.

However, new or well-seasoned, if your oven’s performance bothers you, calibrate it.

So, let’s discover together how to calibrate an oven.

There’s more to an oven than the empty cavity!

Before we get started, fully open your oven door and look around.

• Is the gasket that seals the door cracked or torn or completely compressed so it no longer seals? If so, heat is escaping, cooling the oven down.
• Do you have foil at the bottom of the oven to catch drips? That may be interfering with the oven’s operation. Instead, place something on the rack below while leaving room for air circulation along the sides.

Other possible problems are more invisible. Depending on the result of our upcoming temperature tests, you may have to call in a pro to see if it could be a bad or loose temperature sensor or thermostat control. In an electric oven, a bad heating element might be to blame. And if it’s a convection oven, a faulty fan could be the culprit.

So, when do you call a pro?

If it turns out the oven is off by more than 35°F. If the offset is greater than that, it’s a serious problem that requires the expertise of an appliance repair professional.

Armed with that knowledge, it’s time to figure out what your oven temperature really is. Your pro will want to know that anyway.

350°F Please

The test itself is simple. All you need is an oven thermometer and a baking sheet. The thermometer can be an analog stainless steel one or a 2-piece digital one. If you have one of the analog ones but it’s a few years old, buy a new one.

Be sure to set aside most of an afternoon or evening to do this. The test requires several hours.

How to Figure Out Your True Oven Temperature

1. Place a rack with a baking sheet in the middle of the oven. Put the thermometer on top of the sheet. If your oven is configured so if you hang a thermometer from a rack and it places it dead center, you can do that rather than use a baking sheet. If your digital thermometer has a grate clip, you can use that to directly fasten it to a rack.

2. Preheat the oven to 350°F. This is the gold standard of oven performance.

3. After the preheating is done, wait 30 more minutes. Objects heat up more slowly than the air, so you want to provide plenty of time for your thermometer to get hot.

4. If your oven door has a window, note the temperature reading. Write it down. If there’s no window, quickly open the door to read the temperature, and then rapidly close it and write it down.

5. Repeat for 3 to 4 more on/off cycles. This can take another 30 to 40 minutes or so. Make several more temperature checks at different times in the cycling process. Yes, really. Since ovens heat up and then turn off to average out temperatures, you need to gather data at different times in the cycle order to come up with an average. You don’t want to have all your readings at the low end or the high end. 

6. Turn off the oven (or not, see Bonus Step below) and figure out the average.

If the average is 350°F, yay! Perhaps your problem is more along the lines of hot and cold spots.

If your average is 375°, it’s running hotter by 25° and you will want to lower the calibration to match. If it’s 315°, it’s running cool, and you’ll need to raise the calibration by 35°.

And as noted above, if it’s off by more than 35°, you’ll need to call your pro. It’s more than what your oven can easily handle.

By the way, adjusting the oven temperature calibration should NOT affect broil temperatures.

Bonus Step—Mapping Those Hot and Cold Spots

If you have the time and before you turn off the oven, you can also map the interior for hot and cold spots. All you do is move the thermometer to different suspected trouble spots at different rack heights. Check each spot’s temperature for several cycles, average it, then move to another spot. If it helps, draw an overhead view of your oven, note rack placement, and where the hot and cold spots are.

For example, I know that the back of my oven seems to be cooler than the middle and front. So, I make sure to rotate cookie sheets, pie pans, etc. to ensure even browning.

Calibration Time

Before you start, whether your oven is digitally controlled or uses knobs, locate the manual. If you can’t find it, find the oven’s model number, and do an online search. Although you can do a calibration without the help of a manual, digitally controlled ovens use a combination of button presses to access the calibration mode, making it a quick and easy process if you know what you are doing.

But, if guessing isn’t your thing, call an appliance repair pro.

Electric Ovens with Analog Knobs

Round up a thin flat head screwdriver, a Phillips screwdriver, and possibly needle-nose pliers. You won’t know exactly what you’ll need till you pull off the oven temperature knob. Oh, even if it’s sticky, you should still be able to do a quick tug. Consider cleaning it before reinstalling.

Here’s how Whirlpool explains the next steps:

Remove the oven temperature knob and turn it over. There should be one or two screws on the back of the knob.

If your oven is running hot, turn the screw(s) clockwise. If the oven is running cold, turn the screw(s) counterclockwise. Go slowly and gradually, an eighth of a turn at a time – even a slight turn can result in a large temperature change.

Retest your oven to ensure it reaches the right temperature after calibration. Repeat as necessary.

Authorized Service Appliance Repair notes that factory default should have the knob pointing dead center. If it is offset, then it’s been calibrated before. Make a little mark showing where it is currently pointing so you won’t get confused as you adjust things. Some sources suggest each turn is equivalent to 10 degrees, but this may vary from oven to oven.

The process is time-consuming since you must check the oven temperature average after each adjustment, but it’s not difficult.

Gas Ovens with Analog Knobs

These cannot be calibrated by us common folk. Call in a pro. ‘Nuff said.

Electric Ovens with Digital Controls

This is where your manual comes in handy. There will be a section on oven calibration. It will show you exactly how to access that part of the menu. It may also explain how many degrees you can correct things. If your oven is off more degrees than what your oven will compensate for, call a pro.

The general steps below on how to calibrate a digital oven come from Angi’s, formerly known as Angi's List:

1. Read the oven calibration instructions in your owner’s manual.
2. Locate the keypad.
3. Press and hold two buttons (per the instructions) to get to the calibration mode.
4. Adjust the temperature depending on your initial temperature reading.
5. Save your settings by pressing “Start” or following the manual’s instructions.

It’s important to remember that every oven differs. Some models use up and down arrows to adjust the temperature, while others have prompts. This is why the manual should be your guide.

Parts Select suggests:

On your electronic display, there should be a button that allows you to view the Offset Clock. Check your oven's manual if you aren’t sure. Press this button.

Adjust the clock so it properly offsets the difference in the temperature you noted earlier. Once you’ve selected that, lock it in according to your oven's instructions, and it will be incorporated into your oven's temperature reading.

Whirlpool is quite bare bones:

Check your owner’s manual to determine how to access your oven’s calibration settings.

Use the instructions to increase or decrease the temperature as necessary. Some models use arrows to adjust the temperature, while others may use menu prompts.

Save the calibration setting by pressing Start or following the directions in your owner’s manual.

And Sears simply says:

Most thermostats on electric models are adjusted by using the keypads. Normally, you press and hold two buttons to access the calibration mode, then use the up/down controls to adjust the temperature up or down as needed.

So, you get the gist. Find that manual. Otherwise, if you don’t mind trying different button combinations, you have some hints on how to proceed.

Gas Ovens with Digital Controls

Theoretically, calibration is done the same way as for electric ovens. I don’t find that comforting. But fortunately, I do have the manual for my Maytag gas wall oven. There’s a section under Service Information called Adjusting the Oven Thermostat. This is what it says:

1. Press the OVEN TEMP pad
2. Press the up or down pad and select an oven temperature between 500°F and 550°F.
3. Press and hold the OVEN TEMP pad for about four seconds. The display will change to the oven temperature adjustment display which reads 00°.
4. The oven thermostat can be adjusted up to +35°F hotter or -35°F cooler. Use the up or down pad to select the desired change in the display.
5. When you have made the adjustment, press the CANCEL pad to return to the time of day display.

I would NEVER have been able to figure that out without the manual!

It’s okay to call a pro

If you see your gasket is torn, your oven is off by more than 35°F, you find calibration changes daunting, or you want to know if there’s a fix for those hot and cold spots in your oven, don’t hesitate to call an appliance repair expert.

If the diagnosis is a new oven baking element, be sure to check out our DIY replacement elements.

If you need a new electric oven (we hope not but appliances don’t last as long as we’d like), take the opportunity to replace the electrical cord too. We have 3-wire and 4-wire range cords that can handle 40- or 50-amp loads.

And should you require a new gas oven, it’s also the perfect time to replace the gas line connector. Certified has a universal gas line connector kit that works with both gas ranges and gas dryers.

Get your oven ready for holiday cooking—calibrate it!

Or, at the very least, make a note of your offset temperature and place it by the oven as a handy reminder. And it never hurts to get an oven-safe food thermometer as well.

Disclaimer: This article is for informational and educational purposes only. Certified Appliance Accessories is not liable or responsible for any damages resulting from or related to your use of this information.