Unsafe Gas Heaters Proliferate

Manufacturers argue that, properly installed and operated, these heaters pose no threat, but the many warnings and cautions in the installation manuals suggest that these devices have such a narrow window of safe operating conditions in homes that installing them is asking for trouble.

Unvented gas room heaters, known as “vent-free” gas heating appliances by the industry, include wall-mounted and freestanding space heaters as well as open-flame gas fireplaces with ceramic logs. In 1986, 189,000 unvented gas room heaters were sold in the U.S., representing 38% of all gas space heaters sold. In 1995, nearly 520,000 unvented heaters were sold, representing 69% of all gas space heaters sold (see chart opposite). Some 25 companies produce these products, most of whom are members of the Vent-Free Gas Products Alliance, a division of the Gas Appliance Manufacturers Association.