If your oven is not maintaining the correct temperature, it could be due to a malfunctioning thermostat, a faulty heating element, or a malfunctioning temperature sensor. The issue may also simply be a need for calibration or keeping the door closed.
It could be a simple connection issue. Voltage fluctuation can cause inconsistent temperature regulation. You should check the power source, the socket, the plug, the cord and the fuse, or circuit breaker. All of these rather simple issues could be the actual cause why your oven can't maintain temperature.
Generally, if a oven reaches a temperature above 250 degrees and then shuts off then either the cooling fan is not working, the temperature sensor is faulty or the temperature control circuit on the control board is faulty. Since both ovens are doing this I would not suspect the temperature sensor as the issue.
Place the multimeter on the thermostat. If the thermostat has a reading of zero or as close to zero as possible, it is working fine. However, if it has no reading at all, your oven thermostat is faulty and will need replacing.
Remove the oven temperature knob and turn it over. It should have one or two screws on the back. If the oven is running cold, you will want to turn the screws counterclockwise, and if it is running hot, you will want to turn them clockwise. Turn them gradually, about an eighth of a turn each time.
The cost to replace an oven thermostat is $100 to $350 on average. Signs of thermostat failure include the heating light never switching on or the oven not heating. A thermostat turns the heat on and off as needed to reach the right temperature setting.
Turn the circuit breaker to the OFF position or remove the fuse. Wait one minute, then turn the circuit breaker back to the ON position or install the fuse to reset power to the appliance. This should reset the electronic controls on the Range or Wall Oven.
Your thermostat is responsible for controlling the temperature of your oven. If you find that your food is over or undercooked after setting the temperature correctly there's a chance that your thermostat is faulty.
Electrical Faults
Electric ovens can easily cut out if there is a fault with one of the components inside. Even issues with the clock and the switch can cause the oven to shut off, so pay close attention to these electrical oven parts in particular – both are tell-tale signs that you need professional assistance.
The oven temperature sensor is broken or faulty
One of the most common issues that causes an electric oven to be unable to heat up at all is a broken or faulty oven temperature sensor. In most electric ovens you will find a temperature sensor that monitors the inside of the oven when you are cooking something.
Some of the most common thermostat issues include:
The thermostat is broken, not properly level, or dusty. The thermostat needs to be recalibrated. There is loose wiring causing a thermostat issue.
An oven that won't stay lit could be due to a faulty or weak igniter, gas supply problems, or clogged burner ports, which are common culprits for this issue. A weak igniter is often the primary cause of a gas oven not staying lit, necessitating replacement by a service technician to ensure proper heating.
Then you can simply remove the thermostat from the control panel. Finally, to replace your oven thermostat, just do the opposite of what you have just done - fix it to your control panel; rewire it; feed the wire through and fit the capillary tube back into the oven cavity, and fix everything back together.
If you've switched your oven off but it continues to heat, you may have a faulty part or parts that need inspecting. Your oven's control board, heating elements, temperature controls or knobs and switches may be malfunctioning.
To replace your oven sensor, you'll pay between $100 and $250.
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.
If your oven is not maintaining the correct temperature, it could be due to a malfunctioning thermostat, a faulty heating element, or a malfunctioning temperature sensor. The issue may also simply be a need for calibration or keeping the door closed.
To clean the TempSensor, we recommend: Using a towel with gentle soap and water to rub the needle and cord. Being careful not to submerge the TempSensor connector in water. If the connector is wet, ensure it dries completely before using it again.
The rule of thumb is that if repair costs exceed 50% of the price to install a new oven, you should buy a new oven instead of replacing it. For example, if your oven costs $2,000 but costs $1,500 to repair, you could use that $1,500 for a new and improved oven.
The lifespan of a thermostat is dependent on several factors, including the type of thermostat, usage, and maintenance. On average, most thermostats last about 10 years, depending on the model, usage, and proper maintenance.