If neither the range's oven burners nor the surface burners heat properly, check the gas supply going to the range for proper supply pressure. Get help from your local gas supplier if supply pressure is deficient.
A failing pressure regulator in the range can also prevent oven and surface burners from getting the right amount of gas. You may need to replace the pressure regulator if the gas supply to the range is good but gas pressure going to the oven and surface burners is weak.
For a surface burner not heating properly, check for and clear any clogs from the burner orifice. A failed surface burner control valve can also prevent a surface burner from heating properly. Replace the burner control valve if it won't control gas flow properly.
If your oven burner isn't heating properly, a weak igniter may not keep the burner lit. You'll likely need to replace the oven burner igniter if the igniter glows but doesn't always light the oven burner.
A failed electronic oven control board or failed oven temperature sensor probe could prevent the oven from heating properly. You can test the oven temperature sensor probe by unplugging the range and measuring sensor probe resistance using a multimeter. You should measure about 1,080 ohms of resistance through most probes at room temperature. Refer to the tech sheet for the probe's resistance specification for your range. You can likely find the tech sheet in the control console or taped to the back of the range. Replace the oven temperature sensor probe if you don't measure the correct resistance through the probe. If the probe is okay, then you may need to replace the electronic oven control board.
Some ranges use an oven thermostat to control the oven burner. Replace the oven control thermostat if it doesn't regulate oven burner heat properly.
