For an investment of $100 or less, consumers can put into effect enough energy-saving measures at home to reduce annual utility bills by as much as 25 percent, according to a new government tipsheet. u

"Low Cost, No Cost," a slick brochure published by the U.S. Department of Energy, lists 11 ways that families can save on the cost of fuel oil, gas and electricity.

The government spent about $1.5 million on the pamphlet program, which included postal delivery to 4.5 million households in New England, where heating costs are most severe, an official said yesterday. n

DOE has published and distributed many conservation-oriented booklets, but this latest one attempts to explain how consumers can get the "greatest return for the least effort and expense."

A copy of "No Cost, Low Cost" may be obtained by writing to the Technical Information Center, P.O. Box 62, Oakridge, Tenn. 37830. Brochures should be available within the next two weeks officials said.

One of the low-cost measures call for the installation of a "flow controller" in the shower plumbing. This is a thimble-sized plastic device that can be purchased at many Washington-area hardware stores for about $2.

Inserted between the showerhead and the shower arm, the device reduces the flow of water from about 5 gallons per minute to about 3, the brochure said. It estimates the water savings at 1 gallon of hot water per minute; or up to 4,000 gallons of hot water a year for a family of four.

The Energy Department calculates that the flow controller can save a family $40 a year on electric water heating, or $15 a year for gas water heating.

The brochure also contains some ideas that can save money at no cost to the consumer.

"Anybody with a screwdriver and five minutes to spare can reset the water heater thermostat," the pamphlet says.

Estimated savings for a family with electric water heating would be about $20 a year, if the thermostat is lowered from a setting of 140 to 160 degrees to a setting of 110 to 120 degrees, the pamphlet says. A family with gas water heating would save about $10 a year.

Among the most expensive energy-savings tips listed is one suggesting an extra layer of insulation around the outside of the hot water tank to cut heat loss. The energy department pegs the savings at about $20 a year for electric water heaters and about $10 a year for gas water heaters.

According to the brochure, a consumer can purchase enough foil-backed insulation and tape to do this job for less than $5. Yesterday, however, when The Washington Post checked three stores, only one had the insulation needed for water tanks. The price of $25 more than wiped out the possible savings projected by the department.

Other conservation measures included:

Wash clothes in warm water instead of hot water for an estimated savings of $25 to $50 a year.

Plug gaps around chimney dampers for savings of up to $45 a year in cold climates.

Stuff openings where pipes, ducts or exhaust fans are cut through the attic floor. Use foil-backed insulation or scrap plastic, such as dry-cleaner bags taped in place. "Stopping attic bypasses can save $25 to $80 a year in heating costs," the brochure said.

Caulk gaps that permit cold to infiltrate underneath baseboards and through wall outlets and holes, where plumbing pipes and telephone wires enter the house. When caulk is insufficient, stuff with insulation.

Seal and insulate heating ducts passing through unfinished basements or attics for a saving of up to $100 a year in heating costs.

Turn appliances off or reduce settings when the family is away from home. Room air conditioners can be turned off for an absence of one hour or more; furnace or heating system thermostats can be set back when the family will be gone for more than four hours.

Open window shades on the eastern and southern sides of the house on winter mornings and close them late in the day. On sunny winter afternoons, open shades on the west side of the house. But keep north window shades shut at all time during the winter.

The energy department estimates that all of these 10 ideas can be carried out for a cost of $50 or less. The 11th suggested idea, however, could cost an additonal $35 to $50, officials said.

That fee is for a furnace serviceman to perform an efficiency check and clean and tune the furnace and reset the furnace's thermostat.

In projecting the amount of savings that consumers may expect, the government was careful to include one qualification. "Due to higher fuel costs this year, your energy bill will probably go up," the brochure concedes. But that higher bill can be reduced by as much as 25 percent by heeding the tips in the brochure, the government said.

The energy department said its brochure marks a major shift "from informing people about conservation to actually giving them something to do."

But some other officials had a second view of the pamphlet program, which began with a month-long media blitz of New England. During that period, mailmen delivered copies of the brochure and free flow-controllers to thousands of households.

"It's a campaign stunt and it won't work," Sen. John Durkin (D-N.H.), said at the time the brochure deliveries were underway. He said it will "take more than trinkets to sway New Hampshire voters when people are paying 90 cents a gallon for fuel because Carter bungled the price-supply equation."

Durkin, a steady critic of the president's energy policy, has endorsed Sen. Edward M. Kennedy (D-Mass.) as his candidate in the presidential primary scheduled for New Hampshire on Feb. 26.