The state agency that regulates heating systems and contractors has put off action on part of a proposed burner-testing rule that the natural gas industry says would have been burdensome, unaffordable and without national precedent.

The action reflects Maine’s legacy as a state overwhelmingly reliant on oil for home heating, and its current transition to other fuels, including natural gas.

Following protests last winter from gas companies and some contractors, the Maine Fuel Board voted this month to set up a study committee to review a proposed rule that would have required manufacturers to test all burners used to convert oil boilers to natural gas and propane. The requirement is aimed at safe operations, as the pace of oil to gas conversions grows in Maine. But critics say the sheer number of burner and boiler models and their potential combination in the field makes the testing rule unworkable. It would cost millions of dollars, with no clear safety benefit, they say.

In comments to the board, Chris Green, president of Mechanical Services Inc. in Portland, said existing Underwriters Laboratories burner certifications, along with oversight from professional engineers and licensed installers, already address the board’s safety concerns.

“Mechanical Services believes that is why no other state has required such testing, and why (the American Society of Mechanical Engineers) does not require that the burner and boiler be tested together prior to installation,” Green wrote.

In an interview, Green was asked about insinuations that Maine Fuel Board members had a bias against natural gas, favoring oil and propane. Green said he had heard similar comments privately, but saw no evidence of it and considered the board’s initial rule change to be well-intentioned.

The nine board members are appointed by the governor for three-year terms. A spokesman for the board, Doug Dunbar, noted that Maine law requires members to come from various segments of the fuel industry, and have certain expertise. For instance: Some seats require a valid license as a master oil and solid-fuel-burning technician. Another calls for a licensed propane and natural-gas technician.

The current board includes at least three people employed by oil dealers and two working for heating contractors. One, by law, comes from the State Fire Marshal’s Office.

The new study committee will include an engineer, state inspector, technicians and industry representatives. It’s likely to start work this month, Dunbar said.

The burner testing proposal would have been especially onerous for Summit Natural Gas of Maine, which is starting a subsidiary to help homeowners switch from oil to gas. A large focus of its business is expected to be converting existing oil burners to use natural gas.

Stacey Fitts, regulatory manager for Summit, said he thinks the committee is a good way for the board to get more information. He downplayed the idea of an anti-gas bias by board members, suggesting instead that an education process is to be expected with the rapid expansion of natural gas.

“I don’t cast aspersions on the people on the board; they’re doing what they think is right,” Fitts said. “Given how Maine is situated, it’s understandable that people on the board are on the oil and propane side. As gas becomes more common, that bias will improve.”