It seemed like such a romantic idea, this first fire of the season blazing in the living room. You've arranged the wood just so, poured the wine, started the music.

But now the room is filling with smoke. You open a window and the fire is fine. But it's 30 degrees outside, and you and your companion are huddling miserably at the fireside.

Maybe you should get a chimney sweep to check out your fireplace before trying this romantic ploy again. This is high season for sweeps as they race from house to house, fixing chimneys just as they have for centuries.

Well, okay, not exactly as before: They don't steal small children to send up the chimney anymore, as they did in 18th-century England. Sadly, not many wear top hats and tails into the clouds of soot for luck these days, either.

And rather than just being soot-removers, most modern sweeps also do design, masonry, repair and the occasional raccoon nest removal.

So when you call one to clean your chimney and solve your problem, he'll probably tell you this: If your fire is smoking, most of the time cleaning is not the answer.

"Most people call a sweep when their chimney smokes, but cleaning almost never affects how the chimney operates," says Mark Swann, owner of Top Hat Sweeps in the District.

The only reason to clean a chimney is to prevent a fire in it, Swann says. In most houses, it probably doesn't need to be done on a yearly basis.

In the days before central heating became common, when fireplaces were necessities, they had to be cleaned all the time. In England, the aforementioned unfortunate young boys were used to crawl up flues about nine inches wide, scraping as they went. Most of them didn't live long, as constant exposure to coal dust brought them cancer of the lungs and testicles.

In the American colonies, some people set fire to their chimneys on rainy days to burn off the creosote deposits. Even then this was acknowledged as a bad idea.

Better, it was thought, to take a nice big goose and dangle it down the chimney by a rope around its feet. When the bird panicked and flapped its wings, it knocked off the soot. But before you go looking for a goose ...

"This is the most overswept society on earth," says Swann, who cleans only half of the chimneys he sees. "If you call a sweep, and he tells you he can't come and inspect your house unless he cleans the chimney, call someone else."

An inspection should run from $30 to $45 in the Washington area. To clean the chimney costs anywhere from $60 to $85.

Peggy Florentz, part of a husband-and-wife team called Victorian Sweeps in Arlington (they do wear tails) recommends having someone inspect the chimney for structural damage every year. But if you can see red bricks when you look up the chimney, and no bird nests or debris falls in your face, it's probably clean enough, she says.

Swann recommends cleaning only after burning two to four cords of wood. Other area sweeps are more conservative, and say every one to two cords. But if you didn't burn at least a cord -- that's about two tons -- of wood last season, you're probably all right.

Wood is the best fuel for a fire, the sweeps say. A few people use coal, which burns hotter but is more expensive and much messier. Swann warns against burning a lot of newspapers, which contain lead and chemicals that can pollute the air. And fake logs leave behind a waxy goo in the chimney.

But, back to the question -- if your chimney is clean, why is it trying to asphyxiate you?

Fires smoke for lots of reasons. First, check for obvious things like wet wood and a closed damper. If you're in an old house, especially on Capitol Hill, Florentz says, you may have a fireplace designed to burn coal. These are smaller, don't have a damper and don't work well with wood, she says.

Smoke can also be produced by a fireplace opening too big for the flue. This can be solved by raising the grate a few inches, up on some bricks.

Maybe, though, you're a victim of the energy crunch of the 1970s. After that, houses were built so airtight that the chimney flue became the air intake for the entire house. If the air is coming down, smoke will not go up.

Obviously, a fire needs air to burn, which it gets by creating a flow of air out of the room, through the fire, and up the chimney. In a sealed house, the air is not replaced from the outside. It becomes easier for the fire to reverse the flow, pulling air down the chimney, and sending the smoke into the room. So the fire starts smoking after about half an hour of behaving normally (right after you open the wine).

When you open the window to clear the smoke, you create air flow, and the fire reverses again, since heat normally rises. Since this is a dubious solution in winter, Florentz suggests feeding the fire air through a small vent, which can be added by removing a brick from the outside wall of the fireplace.

Before you start the fire, light a rolled-up newspaper and hold it up the chimney to see if the air is going up or down. This will also heat the chimney and start the draft.

For the same reason, use smaller wood to start. Three small logs have the same amount of wood, but a larger surface area than one big one. This means they burn hotter. A fireplace that is hot draws air four times as hard as one that is cold, for a more efficient fire.

If your fire still smokes, there may be a design problem in the chimney. But all chimney problems are solvable, says Swann, and few are urgent. So if you're told you need a $2,000 relining job or some other expensive remedy, he recommends you always get a second opinion. "I've seen relinings that just created more problems," he says.

Swann takes his fires seriously. After studying English at Harvard and Cambridge, he became an activist against nuclear power in the 1970s, and became a sweep 12 years ago after getting interested in wood-burning as an alternative energy source.

Now his life's work centers on changing this fact: A huge blazing fire in your living room provides lots of atmosphere, but precious little heat.

The air the fire takes from the room is warmer than the air that creeps through cracks and windows to replace it. Most fires don't radiate enough heat to counterbalance that, so they don't make the room any warmer.

A few new baffling devices with curved backs that reflect heat are available. But Swann is in search of the perfect open fire. He is designing his own fireplace, which he says will take much less heat from the room and will be virtually smokeless. He is also writing a book about fireplaces.

"A fire is a wondrous thing," he says. "Very emotional. It gives a sense of a primeval moment in the house. When you think of fireplace blazing in the middle of a house full of flammable objects, it's incredible."