Gas oven repair

To fix broken household items, you need to know how it works, what can go wrong, how to identify the problem, as well as steps to fix it. Here’s what you need to know about gas oven repairs.

How does it work?

Natural gas or propane from an outside source is piped into the furnace where it is burned to produce heat. Typically, a fan-driven forced air distribution system blows hot air through ducts that vent to different rooms in the house. Older gas ovens use a permanent pilot ignition. Maintenance involves turning off the pilot each spring and relighting it each fall. Newer, more efficient gas ovens use an electrical spark to ignite the gas as needed.

What can go wrong?

Most gas ovens are quite reliable. What are the symptoms of problems? The oven may not produce heat or may not produce enough heat. The pilot light may repeatedly go out or refuse to come on. The thermocouple may be defective. Pilot may light but not burner. The oven can be noisy. There is some maintenance and some minor repairs that you can do. However, major service should be left to a trained technician.

Suggestion to fix it

To minimize problems with your gas heating system, take time each month to check your air filter and clean or replace it if necessary. Once a year, clean the blower blades, lubricate the blower motor, and inspect the belt.

How can I identify the problem?

If there is no heat, check the electrical service panel for a blown fuse or tripped circuit breaker. Relight the pilot light (see below).

If there is not enough heat, adjust the burner air shutter (see below); and clean burner ports (see below).

If the pilot light does not come on or stays on, carefully clean the pilot hole with a toothpick, test the thermocouple and replace if defective (see below).

If flame flickers, adjust pilot (see below).

If there is a popping sound when the burner lights, adjust the pilot to a higher setting and clean the pilot orifice and burner ports.

If the burner takes more than a few seconds to light, clean the pilot orifice and adjust the pilot light.

If burner flame is even, clean burner ports. If the burner flame is very yellow, clean the burner; open the vents in the furnace room to provide more air; adjust burner air shutter.

If heater makes a dull noise when burners are off, clean heater and adjust burner air shutter.

If the air is too dry, wash or replace the evaporator pad if you have a humidifier; try humidistat; and adjust the water level float to raise the water level.

If some rooms are too cold and others too hot, the distribution system may need to be balanced. See the Fix-It Guide to Forced Air Distribution at FixItClub.com

Suggestion to fix it

Make sure your filter is the correct size for your furnace.

What parts, materials and tools do I need?

Some replacement parts for gas ovens are interchangeable (filters, clips) and are available at your local hardware store. Others, such as burners and controls, must be purchased from the manufacturer or aftermarket supplier or through a heating equipment supplier listed in the local telephone book.

The main tools you will need to repair a gas oven include the following:

* Screwdrivers

* keys

* Pliers

* wire brush

* Multimeter

What are the steps to fix it?

To light the pilot on a fixed pilot (always on) ignition system, follow the lighting instructions located near the control. Otherwise, try these steps:

Light the pilot:

1. Press and hold the pilot control knob to start the pilot. Place the control knob in the pilot position. Hold a long match under the pilot gas port.

2. Press the control knob; the pilot should light. Hold down the control knob until the flame burns brightly (about 30 seconds). Release pressure on the knob and turn it to the on position.

3. If the pilot goes out when you release the control knob, try relighting by holding the control knob in longer. If the pilot goes out again, check the thermocouple (below).

Adjust the pilot:

1. Remove any cap covering the pilot adjusting screw on a combination control.

2. Turn adjusting screw counterclockwise to increase flame or clockwise to decrease flame. It is properly adjusted when the flame wraps around the thermocouple bulb by 1/2 inch and appears dark blue with a small yellow tip.

Test and replace a thermocouple:

1. Hold control knob to pilot and light pilot as above.

2. Unscrew the thermocouple fitting with an open-end wrench.

3. Set a multimeter to the DVC (lowest voltage) scale.

4. Attach one lead from the multimeter to the end of the thermocouple tube closest to the pilot and the other lead to the fitting on the other end of the tube.

5. If the multimeter shows a reading other than zero, the thermocouple is working. Replace thermocouple tube.

6. If there is no reading, you will need to clean or replace the thermocouple by following steps 7 through 11.

7. Release the control knob and close the main gas valve on the gas supply line leading to the burner. Disconnect power to the burner at the electrical service panel.

8. Remove the thermocouple from its mounting bracket.

9. Clean combination control and install new thermocouple, hand tighten then turn 1/4 turn with wrench.

10. Insert the thermocouple into the pilot holder, being careful not to bend the tube.

11. Turn oven on and relight pilot (above).