When some Catholic priests make the rounds of their Maryland churches over the next few weeks, they will check more than vestments and altar wine supplies.

The priests are certified energy auditors, trained by the state of Maryland to uncover ways of saving energy -- and money -- for their churches and schools. They are only one of the tacks local churches and synagogues are taking in the battle against rising energy costs.

The churches often have unique heating problems: a large cavernous area that needs heat only a few hours a week next to offices and smaller meeting rooms that must be heated all week long.

Their energy-saving methods range from the costly business of converting a church's furnace from using heating oil to natural gas to simply reminding employes to turn out lights and lower thermostats.

Patrick Canaan, energy liaison for the Catholic Archdiocese of Washington, has encouraged dozens of priests and school and parish representatives to take advantage of a training program. Maryland ran last February for representatives of nonpublic schools. Canaan said the suggestions made by the 55 volunteer auditors, both Catholics and non-Catholics, could save the institutions surveyed 20-to-40 percent on their fuel costs this winter.

Washington Cathedral climbed on the energy conservation bandwagon early, but its officials are still looking for ways to cut their energy costs. This year the cathedral spent $25,000 to convert its heating plant from oil to gas, according to Sylvan Salter, director of facilities engineering. Barring dramatic increases in the price of natural gas, Salter said energy savings at the cathedral, schools and administrative buildings on the grounds will more than cover the initial investments the first year.

Salter said the cathedral spent more than $178,000 on fuel for the fiscal year that ended in September, compared with close to $137,000 the previous year. Although that figure represents a substantial increase, the cathedral administrator had expected much higher bills and allotted $237,000 to cover them, Salter said.

"We overestimated the rise in fuel costs," said Salter, "but most of that difference is the result of our efforts to cut back." Those included fixing leaky steam and pipes, turning back thermostats, caulking windows, reducing the hours the cathedral is open and closing the two main cathedral entrances, according to Salter. This year, he said, officials will continue to drum home the conversation message, including urging employes to make sure the bell tower door is closed. "Otherwise," Salter said, "it acts like a chimney, sweeping all the warm air right out of the church."

Other smaller churches, like Central Baptist Church in Bladensburg and Bells United Methodist Church in Camp Springs, also have converted to natural gas or plan to do so soon.

Other religious institutions have changed the way they heat their buildings and offices. Mishkan Torah Congregation in Greenbelt now uses a small space heater that warms only the office area. The sanctuary at Fort Washington United Methodist Church is equipped with a thermostat that will turn on the heat for only specified times and Central Baptist Church in Bladensburg now has seven thermostats to heat specific parts of its building.

By using the equipment, Central Baptist was able to cut its fuel bill from $5,900 to $4,200 from 1978 to 1979, according to its pastor, the Rev. Lee Smith.

The First Baptist Church of Washington plans to use zoned thermostats this winter after discovering that it had spent more on fuel the first six months of this year -- $12,150 -- than it did during all of 1979, according to the church's business manager, Leonard Whitehead.

Other churches are trying to schedule church meetings with energy conservation in mind. Briggs Memorial Baptist Church near Westmoreland Circle has just decided to hold all its meetings on Wednesday nights, rather than several times throughout the week. First Trinity Lutheran Church in Northwest Washington now holds all of its meetings after Sunday services and All-Saints Sharon Chapel Episcopal Church in Alexandria plans to reduce its meetings next month when temperatures drop.

Asbury United Methodist Church at 11th and K streets NW also has consolidated its meetings but its pastor, the Rev. Frank Williams, is not sure that will reduce the church's energy costs significantly. Because it runs a day care center and program for the elderly, said Williams, he can turn back thermostats only minimally.

Williams said the church may have to eliminate some of the programs if fuel costs continue to rise.

Aside from the obvious monetary savings, Canaan said he has been pushing local Catholic churches and schools to conserve energy because it's the Christian thing to do.

"Conservation is as old as Genesis," said Canaan. "When God talked to Adam and Eve about giving man dominion over the air, the birds and the land. He never had in mind misuse or excessive use."