Oven temp not correct

Well, your temp sensors can still be bad. If not, there's always a new control board you buy!

However, I wouldn't drink water from that oasis without making ABSOLUTELY sure I'm not seeing a mirage.

The only common denominators between your upper and lower oven temp readings is the firmware and the oven thermometer you are using to visually check the temps.
What type of thermometer are you using to check your oven temperatures with?
If it's not a digital thermometer used specifically for testing ovens, you might just be leading leading yourself astray.
You need a calibrated thermometer. If I don't have a calibrated digital thermometer on me, I use two or three oven thermometers (the dial type) and average the readings.
It's the only way to be as close as possible with a digital probe.

If you have thoroughly verified that your oven is in fact not reading the correct temperature, then you can adjust it +/- 35 degrees F via your oven's control panel.
To adjust the oven temperature:
1 - Press Setup pad.
2 - Select the down arrow to scroll to the next screen.
3 - Select Temp Adjust using the Quickset pads.
4 - Select upper or lower oven (select models).
-"Set temperature offset using the Upper Set Knob" is displayed.
5 - Enter the desired temperature change using the Set knob.
The temperature can be increased or decreased up to 35 degrees.
The temp. change is displayed at the top of the window.
6 - Press the Set knob to accept the change.

Now, if you are still worried about the temp. reading being off, replace both the upper and lower temp sensors. That's all you can do besides replace the main board.

check that the oven thermostat probe inside the oven is not close to or touching one of the upper oven elements

Hi,

Electronic ovens with a digital display use a sensor to monitor oven temperature. To solve temperature problems for these models, you need to replace the sensor. On some digital-display models, you can calibrate the temperature using the key pad. See your operator's manual for details.

Ovens without a digital display often use a mechanical system for controlling temperature. On many of these units, you can remove the thermostat knob and adjust the knob itself to more accurately represent the actual setting of the thermostat.

When you remove the knob, there's a screw on the back of it with a small calibration plate, you can loosen the screw, adjust the plate, and then tighten the screw again. If the knob isn't adjustable, and the oven temperature is off by more than 30 to 40 degrees, you need to replace the thermostat to solve the problem.

Let us know if you want something else please accept the solution.

If you are monitoring the oven temperature with an analog style thermometer you may actually be ok, but seeing the thermometers slow reaction time.
Some newer ovens actually do pre-heat beep prior to reaching temp in an effort to conserve eelectricity.
A good home test is to try your oven at several different temps to see if there is any variation in internal temperature. Try it one day on 300, the next at 375 and another day at 450. Give your analog style thermometer time to catch up (usually just about 15 min) and leave it on for a half an hour to see if the temp maintains.
Also Beware of aluminum foil AND THE NEW OVEN LINER MATS as they can alter oven performance bay absorbing and blocking the ovens natural heat radiation and convection air flow currents that happen in all ovens, not just convection models.
Another interesting fact is that older ovens used a thermostat in them that operated much like your thermometer and was very slow to react making the oven typically about 100 degrees hotter than where the customer set it. This was just a fact of life before the advent of electronic temperature management and became noticeable when people began trying to bake older "hand me down" recipes in the newer ovens with less than stellar results.
You can mimic the older oven performance by preheating the oven about a hundred degrees higher than called for and after it reaches temp, re-set it to the correct temperature and put the items in right away.
If you find your temperatures fluctuating ask your servicer to replace first the temp sensor and as a last resort the control board as this part is usually pretty expensive.
Good Luck with this!

Is this oven gas or electric? If it is gas then it can be normal to see 30 to 50 degrees difference in tempature. The tempature in a gas oven works on the average tempature. For example: The oven tempature may rise all the way up to 370 degrees. Then the burner will shut off. And then the tempature can drop all the way to 330 degrees. Then take 330 and add that to 370 then divide that number by two and the average tempature will be 350. If your oven is electric then the tempature should be much more consistant but can have a 10 to 15 degree variance. Also the standard oven tempature guage that you put in the oven or even the temp guage built into the oven are not very accurate. We us a Fluke meter with a thermocouple to calibrate an oven. So to check your oven for proper tempature regulation you will first need to let the oven pre-heat for about 15 minutes. Then place the thermocouple in the center of the oven. If the oven is electric the take a temp reading every 5 minutes and average them out. If the oven is gas then you will need to take a temp reading when the tempature reaches it's highest and lowest points. Take at least 5 consectutive readings and average them out. You should get an average within 10 degrees of set temp(350 degrees). If it is off by 35 degrees or less you can usually caluibrate the thermostat back to proper temp. This procedure can be different for each range model. If it is more than 35 degrees off or you are getting irratic readings then the thermostat or thermostat components might need to be replaced.

There is a calibration method to adjust the oven thermostat plus/minus 35 degrees if it is a digital display. The method varies depending on the model range. This calibration method is used to adjust the thermostat if it is not keeping proper tempature. For example if you are setting the oven to 350 and the actual temp it is keeping is 325 then you could use the calibration method to adjust it plus 25 degrees to correct the temp. Just so you know electric ovens will keep a pretty even temp but gas ovens will vary by 40 or more degrees to keep an "average" temp. For example the burner will come on when the oven is 330 degrees and turn off at 370. 330+370 then divide by 2=350. So a oven thermometer may not show you the temp you set it at in a gas oven but does not mean the oven temp is off.

I have a kenmore gas range with digital display that will let me increase the temperature up to 35 degrees f*. It says to press BAKE for 6 sec., then use the number pad to increase or decrease then press START.
Hope this helps
Don

Oven temperature sensor, here's a link to the part you need.

http://www.appliancepartspros.com/part_details.aspx?part_id=2023670&pn_=WB21X5301

You may not need anything. Most people test their oven with a dial type oven thermometer. They are slow to react and often not very accurate. When I test an oven or install a new thermostat, I use a digital thermometer with a remote temperature probe, hanging from the center of the oven, which shows the temp in tenths of a degree. I let the oven cycle on and off at least three times, then take the high and lower readings on the next cycle and average that out to see what the actual oven temp is. Most of the time, if there is a dial type thermometer in the oven it is very slow to react. After 3 to 5 cycles, they often show close to what the actual oven temp is, but the only way to know for sure is to use the more accurate digital thermometer. Most ranges with digital displays can be adjusted + or - about 35 degrees. Check your users manual for this info, but don't mess with it until you have checked the oven with a digital thermometer! Please don't bother rating this solution, as anything but a Fix-Ya drops my score. Thanks.

Could be a couple things. If your machine is actually failing either a control board or an oven sensor.

Also measuring the temperature can only be done by a tech unless you have a special tool. Oven thermometers are inaccurate. Plus most ranges should vary temp between 50-75 degrees unless has a feature or the more recent ones keep it between 15-25 degrees.

Try the biscuit test, buy some biscuit, brand not important, i just say pillsbury. Cook exactly as recommended on package. If results are a little overcooked or a bit undercook try a feature called Adjusting the oven temperature or Calibrating the oven. This can be done by following the instructions in your book.

Maytag.com click support click manuals put in model MER5775QA (notice i took off your models S) open the Use guide, page 14