Gas Detector Sounds

Problem: Alarm designed to detect presence of gas leaks goes off.

Background: Special alarms are available to detect natural gas or liquid propane (LP) gas leaks which could build up to concentrations that could result in explosions or flash fires. Similar to smoke detectors in appearance, they are de signed to sound before dangerous levels have been reached, giving you time to correct the problem or vacate the premises.

What to do: If your alarm sounds, take it seriously and immediately check for the odor of gas and for the cause. Situations that can result in gas leaks include:

1) attempting to relight the furnace when the electricity is off
2) pilot lights on furnaces, gas dryers, or water heaters have gone out or have blown out
3) chimney or flue malfunctions which return unburned gases to the basement
4) broken or cracked gas lines or fit tings caused by the movement or jarring of appliances or by metal fatigue
5) malfunctions of gas safety valves which should shut off gas when trouble occurs into the basement of natural gas found in the earth, or broken gas mains in the street, which allow gas to enter the basement along water or gas pipes.

Also check the electrical boxes of appliances for overheating. If none of the potential problems listed above exist, vacate the premises and call the fire or gas company.
Because of the way gas detectors work, false alarms can occur if the unit is installed beyond furnace areas where they can be affected by hydrocarbon gases that are found in items such as hair sprays, cleaning products, paint, cooking odors, and aerosol products. Alarms can also sound if the basement has been painted or fumigated recently, if furniture is being refinished, if cleaning is being done with flammable materials, or if gasoline or flammable liquids are being dangerously stored in open cans.

Special advice: Gas detectors are not intended to detect small concentrations of gas trapped by the walls of the furnace. (To avoid triggering an explosion, always open furnace doors and air out the area before trying to relight pilot lights A detector may have sensor lights, indicating that it is plugged in and operational. Gas alarms should be tested at least once a month by briefly holding either an unlit butane lighter or cotton dipped in alcohol under the sensor opening. If the alarm beeps, instead of sounding continuously, it indicates there is a problem and that the unit should be serviced.

Helpful hint: Gas detectors should never be plugged into outlets operated by a wall switch. To detect natural gas, detectors are normally mounted 6 inches to 12 inches from the ceiling and about 4 inches to 12 feet from gas appliances. To detect propane gas, which is heavier than air, the units are normally mounted 6 inches to 12 inches from the floor.