The Metropolitan Washington Council of Governments, moving to remedy the area's faulty emergency disaster warning system, recommended yesterday that local jurisdictions use the federally operated sirens only to warn the public of enemy attacks.

The unanimous vote by the 22-member board of local government officials urges that the warning system, plagued in recent years by sirens that either fail to sound or go off accidentally, no longer be employed to alert the public of peacetime disasters such as tornadoes, floods or serious accidents.

The recommendation, which apparently brings to a close an often controversial 20-year debate over the use of the country's only fully federally financed alarm warning system, will be followed voluntarily by all member jurisdictions of COG, with the possible exceptions of Loudoun County and Alexandria, said Thomas P. Rametta, the principal public safety planner for COG.

Officials at the Federal Emergency Management Agency, which pays for and operates the alarm system, said they are in the midst of spending $1.2 million to improve it, and will continue to use it for defense emergencies such as a nuclear attack.

FEMA officials added that the local warning system is no less reliable than other alarm warning systems throughout the country.

"If they don't want to use them to warn of natural disasters, that's their decisions, but the system will remain in place," said Thomas Hardy, deputy regional director for FEMA.

Acording to Rametta, a recent test of all 467 alarms in suburban Maryland, District and Virginia areas revealed that the system malfunctioned 30 percent of the time, with the alarms failing to respond to radio or telephone signals that trigger them. He added that media and loudspeaker alert systems are more reliable and less prone to technical problems.

He added that few people know the meaning of the different siren blasts and even in cases when they have worked properly, people are unsure exactly how to respond. The sirens are usually located in places such as schools, government buildings, downtown areas and near large bodies of water that could flood in the event of a war or natural disaster.

FEMA officials, however, played down the results of the FEMA-conducted test, stating that all but nine of the alarms "could have been activated" in case of an emergency.

FEMA, in response to past COG recommendations, according to Hardy, is installing a new system to activate the alarms by more reliable radio signals.

The switch to the new system, which Hardy said began two years ago and should be completed by 1988, would reduce -- but not eliminate -- the number of accidental alarms, most of which are caused by power surges, construction work on telephone lines, and other nonradio-wave-related sources.

He added that the national FEMA office has been slow to allocate the necessary $800,000 to complete the transition process because the alarm system "is not a high enough priority" for them at this time.

Rametta said that even with the new radio wave operation, the system has "performed as poorly as ever," because radio signals are often blocked by trees and buildings.

Accidental warnings, such as the blaring of two sirens in Gaithersburg at 4:30 a.m. and 6 a.m on the same day last year for no apparent reason, prompted complaints , COG officials said.