A yellow, lazy flame on your range is telling you something. Here's what.

A clean burner with the right mix of gas and air burns blue, with even flames all the way around.

• Yellow or orange flames mean the gas isn't burning cleanly. Often the ports are clogged or the air shutter needs adjusting. A yellow flame leaves soot on pans.
• Uneven flames, tall on one side and short on the other, mean some ports are blocked.
• Flames that lift off the burner or blow out easily can mean too much air or the wrong gas pressure.

• Wipe spills as they happen. Boil-overs that bake on are what clog the ports.
• Soak the grates and drip trays in hot, soapy water at close. Heavy grime may need half an hour or more.
• Wipe the knobs and front panel. Grease on the knobs gets into the valves.
• Dry everything before it goes back on.

Use the cleaners and scrub pads the manual allows. Some finishes scratch easily.

With the range cool and the gas off, lift out the burner heads if your model allows. Use a stiff brush or a straightened paper clip to clear the small ports. Don't use a toothpick, which can break off inside. Don't make the holes bigger.

Let the burners dry completely before you put them back. Water left in the ports makes the flame sputter.

Many ranges have standing pilots that stay lit all day. When a pilot keeps going out, the cause is often a dirty pilot opening, a draft from the hood or a door, or a worn safety part called a thermocouple.

Relight a pilot only the way the manual or label shows. If it goes out again and again, call for service. Don't hold a knob in or block a safety part to keep it lit.

Once a month, have the range pulled away from the wall on its casters, if it's set up for that. Clean the back of the range and the wall behind it. Grease back there is a fire risk. Check that the gas hose and its restraint cable are in good shape when you put it back.

If you smell gas, don't light anything or flip any switches. Turn off the gas at the shut-off valve if you can do it safely. Get everyone out of the building, then call your gas company or 911 from outside. Call a technician once the gas company says it's safe.