Carbon Monoxide And Home Inspectors
home inspection tech talk

(The Silent Killer)

A home inspection should include a check for carbon monoxide. Carbon monoxide (CO) is a poisonous gas that kills nearly 300 people in their homes each year. Nearly 5,000 people in the United States are treated in hospital emergency rooms for CO poisoning; this number is believed to be an underestimate because many people with CO symptoms mistake the symptoms for the flu or are mis-diagnosed and never get treated. CO is a colorless, odorless, toxic gas that is produced by the incomplete combustion of solid, liquid and gaseous fuels. Appliances (such as stoves, furnaces, room heaters, water heaters, etc.) fueled with gas, oil, kerosene, or wood may produce CO, as may a fireplace, a charcoal grill, or gasoline powered engine. If such appliances are not installed, maintained, and used properly, CO may accumulate to dangerous levels. Carbon monoxide is produced by burning any fuel. Therefore, any fuel-burning appliance in a home is a potential CO source. Appliances kept in good working condition, produce little CO; however, improperly operating appliances can produce fatal concentrations in a home. Similarly, using charcoal indoors, or operating a gasoline powered engine in a garage can cause CO poisoning.

Symptons Of CO Poisoning

Carbon monoxide poisoning can kill. The initial symptoms of CO are similar to the flu (but without the fever). Symptoms of carbon monoxide poisoning are similar to flu-like illnesses and include dizziness, fatigue, headaches, nausea, and irregular breathing. If any of these symptoms are experienced, and you feel better when you go outside your home, and the symptoms reappear once you're back inside, you may have CO poisoning.

Things You Can See

The home inspector should look for rusting or water streaking on vent/chimney. Loose or missing furnace panel. Sooting. Decreasing hot water supply. Furnace unable to heat house or runs constantly. Unfamiliar or burning odor. Loose or disconnected vent/chimney connections. Debris or soot falling from chimney, fireplace, or appliance. Loose masonry on chimney. Moisture inside of windows. Visible rust or stains on vents and chimneys. An appliance that makes unusual sounds or emits an unusual smell. An appliance that keeps shutting off (many new appliances have safety components attached that prevent operation if an unsafe condition exists). Therefore, do not try to operate an appliance that keeps shutting off; call a service technician.

Things You Can Not See

Damaged furnace heat exchanger. Internal appliance damage or malfunctioning components. Improper burner adjustment. Hidden blockage or damage in chimneys. Some but not all of these conditions can be checked by a home inspector during a home inspection.

Dangerous levels of CO can be prevented by proper appliance installation, maintenance, and use. Proper installation is critical to the safe operation of combustion appliances. All new appliances have installation manufacturer's instructions that should be followed exactly. Local building codes should be followed as well. Vented appliances should be vented properly, according to manufacturer's instructions. Adequate combustion air should be provided to assure complete combustion. All combustion appliances should be installed by professionals. Make sure that rooms where an unvented gas or kerosene space heater is used is well ventilated; doors leading to another room should be open to insure proper ventilation. Do not use an unvented combustion heater overnight or in a room where a person is sleeping. Do not burn charcoal indoors or in a garage. Do not use a gas range or oven for heating. Do not leave a car running in a garage. Do not operate unvented gas-burning appliances in a closed room.

CO Prevention

The first line of defense against carbon monoxide is to make sure that all fuel-burning appliances operate properly. Home heating systems should be inspected each year for proper operations and leakage; chimneys and flues should be checked for blockages, corrosion, and loose connections; the home inspector will look for these conditions during the home inspection. Service technicians should check all heating appliances and their electrical and mechanical components, thermostat controls ,and automatic safety devices. Individual appliances should be serviced regularly. Kerosene and gas space heaters (vented and unvented) should be cleaned and inspected to insure proper operation. Never service appliances without proper knowledge, skills, and tools.

Install A CO Detector For Added Safety

Home inspectors recommend CO detectors that meet the requirements of Underwriters Laboratories (UL) standard 2034. Since the toxic effect of CO is dependent upon both CO concentration and length of exposure, long-term exposure to a low concentration can produce effects similar to short term exposure to a high concentration. Detectors that meet the UL standard measure both high CO concentrations over short periods of time and low CO concentrations over long periods of time. The effects of CO can be cumulative over time. Detectors sound an alarm before the level of CO in a person's blood becomes crippling. Detectors that meet the UL 2034 standard currently cost between $35 and $80. CO gases distribute evenly and fairly quickly throughout a house; therefore, a CO detector should be installed on the wall or ceiling in sleeping areas but outside individual bedrooms to alert occupants who are sleeping. Properly working carbon monoxide detectors can provide an early warning to residents before the deadly gas builds upto a dangerous level.

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