Don't light either of those fireplaces

Our 25-year-old house has two fireplaces, one upstairs and one downstairs. When using the upstairs fireplace, the closet wall gets so hot you cannot hold your hand on the plaster. We also get an odor of scorching wood. I suspect there may not be a proper fire wall behind the fireplace. What can be done besides not using the fireplace? John E. Brown St. Paul, Minn.

If it were my house, I wouldn't use either fireplace until corrections are made. The condition you describe sounds extremely dangerous.

Get in touch with an experienced masonry contractor or fireplace mechanic to make an on-site inspection. He may need to remove the plaster finish over the chimney in order to assess the cause and recommend a cure for the overheated chimney shell.

The scorched-wood smell is ominous, in my opinion, and indicates that some of the framing members may be near the ignition point.

The remedy to overcome the fire hazard lies in what is discovered when the chimney plaster is stripped off the wall. Let the inspecting brick mason advise you of remedial steps to be taken so that both fireplaces can be safely used.

Meanwhile, I wouldn't burn a single ember in either fireplace.

Great strides in fireplace-engineering efficiency have been made in the last few years. Existing fireplaces may be modified or redesigned to minimize energy waste.

Unless exterior combustion and draft air are provided, large amounts of expensive artificially heated interior air are consumed by combustion. New air intakes may be located in crawl spaces, behind or alongside the chimney.

Ash pits also may be adapted as sources of outside air to feed combustion.

Fireplaces such as yours, which are located entirely within the structure, provide maximum thermal benefit. The masonry mass stores heat inside the house and radiates it even after the fire has gone out.

If you want more specifics on retrofitting an existing fireplace so as to achieve greater efficiency and thus save money, get in touch with the Brick Institute of America, 1750 Old Meadow Road, McLean, Va. 22002. Phone: (703) 893- 4010.

Iron wood stoves may be inserted in, or in front of, existing fireplaces, for example. Here in southeastern Arizona, we slipped a wood stove into our fireplace and now use about three-quarters less firewood than before.