IT CRACKLES, it pops, it glows.

Heat your feet and warm your toes.

Yes, it even cooks. But get your order in now. These little babies are selling like hot cakes and you won't want to be caught without one come the first freeze.

Woodstoves. If anything has changed since last winter, when orders for the devices stacked up like firewood, it's that they're selling even faster.

"This month is beginning to get madhouse," said Ginger Nusser, sales manager at ACME Stove in downtown Washington. "We're about a month behind on incoming stock."

The continued upward spiraling of heating oil costs, say stove dealers is prompting more and more homeowners to think seriously about wood as a winter fuel source.Even President Carter, who has proposed extending energy tax credits to cover wood burners, has ordered some for his own house on Pennsylvania Avenue.

Wood stoves haven't enjoyed such popularity since they were absolutely essential. In the 50 or so years since then, however, they haven't become much safer, either.

Improperly installed, wood and coal burning stoves can send home and possessions up in flames. Authorities fear that many new owners could be creating unnecessary fire hazards by installing the stoves themselves, without proper guidance or inspection.

"I'm afraid that many people are using products and methods that are inadequate," said John R. Anderson, manager of the engineering division at the National Fire Protection Association.

A year ago The Washington Post reported that many new owners -- perhaps even a majority -- were installing their stoves illegally, without the necessary building permit. Most had no other choice because state and local building codes in the Washington area required that stoves show the label of a recognized testing laboratory, such as Underwriters Laboratory (UL), before the permit could be issued. The vast majority of stoves, including some of the highly regarded European models, had not received such approval.

Dealers were unable to install many of the stoves they sold because they could not obtain a building permit for them.

In the ensuing months, more stove manufacturers have commissioned testing, waited in line and received labels. Last September, UL had issued safety labels to 10 manufacturers. This fall, more than 30 companies are selling their stoves with UL's blessing.

Still, dozens of stove models are thriving in the market without the UL, BOCA (Building Officials Conference of America) or ICBO (International Conference of Building Officials) imprimatur. ACME alone carries between 120-140 models, from 75 different manufacturers. Many do not carry testing labels.

In order to ensure that stove buyers need not fear, at least, seeking a permit and safety inspection for such stoves, some county inspectors have chosen to bear themselves the responsibility of deciding whether non-label appliances are safe.

Other inspectors have pulled up their britches; they close one eye as illegal stoves are bootlegged daily into their jurisdictions.

"We're having to play this one by ear," said Edward Bethel, chief building inspector in Arlington. "We are giving out a lot of permits for stoves that aren't listed. If we didn't, we'd practically rule out the public using them." Bethel says Arlington inspectors must "rely a lot" on the reputability of the manufacturers. "It's a little like letting the foxes take care of the chickens. But at least now we get a chance to make sure they're put in safely. I think we're competent enough to make these determinations."

Unlike Arlington and other Northern Virginia jurisdictions, Prince George's and Montgomery Counties, and the District of Columbia, have stood firm. For a time, Prince George's was issuing permits for well-known brands that had yet to be tested and approved, such as the reputable Jotul and other European makes.

But no longer. "There's a reasonable variety of (labeled) stoves available," including, now, the Jotul, said Prince George's plans examiner Don Barrett. "There's no justification for allowing stoves that do not have a listing."

Nusser says "the first question we ask our customers is which county they live in."

What authorities fear most is that a majority of stove buyers are ignoring the law entirely, installing their heaters without the mandatory building permit even when the stove carries a proper label.

Estimates on the number of illegally installed stoves vary, but most officials would agree with the Alexandria inspector who said, "We know that a lot of people are putting them in without permits. But there's not much we can do about it."

Said Barrett: "There are probably as many going in without permits as there are with."

Most area jurisdictions report issuing permits at a rate of about one a day, sometimes eight to 10 a week, straight through the summer months.

A recent study performed by the Maine Audubon Society, with funding from the U.S. Department of Energy, found that of 300 wood stove owners surveyed in that state, 80 percent installed their stoves themselves. Thirty-eight percent installed them "without the use of any guidelines."

Guidelines are essential because temperatures on the skin of some wood or coal burning stoves can reach 900 degrees or more. Standards developed by such organizations as the National Fire Protection Association, and enforced through local building codes and laboratory test methods, dictate that proper clearances between the stove, the flue and combustible materials in the house be maintained for the stove to operate safely.

A typical clearance requirement, for instance, is 36 inches between stove and combustible walls and 18 inches between the stove pipe and combustible walls and ceiling materials.

Testing by UL often demands the manufacturers make changes in stove design and clearance requirements to ensure safety. Before labels are granted, manufacturers must spell out clearly how the stove should be installed and operated.

Authorities say many stove owners do not read the directions, installing stove pipes through ceilings without protective collars, placing free-standing stoves on wood floors without a fire shield, attaching flues to chimneys that are not built to withstand the intense heat generated by wood stoves or putting them in mobile homes against all informed advice.

"Most fires are caused by improper installation, maintenance and operation," said Robert Peacock at the National Bureau of Standards' center for Fire Research. "Only a small minority are caused by malfunctioning equipment or design defects."

Peacock recently completed a survey of fires involving solid fuel burning appliances. Between 1975 and 1978, he said, more than 11,000 such fires were reported to the U.S. Fire Administration by the 21 states that participated. More than 100 fires involved injuries. Sixty-five persons died.

(The Center for Fire Research will soon undertake studies of solid fuel burning stoves to analyze safety features. Peacock says most of the available data is 35 to 40 years old and doesn't include current materials.)

While many state and local officials are crossing their fingers and hoping programs designed to increase public awareness will help lessen the likelihood of unnecessary fires, some government agencies are investigating stronger laws that would enforce stove safety and proper installation.

In Massachusetts, for instance, all stoves for sale after Jan. 1, 1980, must meet UL requirements. As recently as a year ago, 25 fires were reported each month during the heating season there, said Buz Laughlin in the state energy office. "With the increase in sales, we were expecting real problems, " Laughlin said.

And now the federal government shows signs of stepping in. Wood and coal burning stoves have become a priority item at the Consumer Product Safety Commission (CPSC). The CPSC recently granted a petition to require safety labeling on stoves, sales literature and shipping cartons that would show correct installation instructions and clearance requirements.

Should such a petition lead to regulation it would, under CPSC rules, virtually require that all stoves sold in this country be safety tested to back up labeling claims. The commission staff is expected to begin work on the petition next year.