Buildings Burning No. 6 Oil Must Convert by June 2015

Local Law 43 and other state legislation regulating heating oils (No. 4 and No. 6) in New York City were put in place to address the public health hazard presented by these fuels. The rules affecting types of oil used in boilers were passed in April 2011 as part of an update to Mayor Bloomberg’s environmental agenda.

Local Law 43 and other state legislation regulating heating oils (No. 4 and No. 6) in New York City were put in place to address the public health hazard presented by these fuels. The rules affecting types of oil used in boilers were passed in April 2011 as part of an update to Mayor Bloomberg’s environmental agenda.

Under the rules, by 2015, existing boilers must switch from No. 6 oil to a low-sulfur version of the No. 4 heating oil or to an equivalent cleaner fuel. Any newly installed boiler would have to burn an even less polluting grade—low-sulfur No. 2 oil—or natural gas, or an equivalent low-emission fuel, which would in effect eventually phase out No. 4 oil. Boilers not replaced by 2030 would need to be modified to meet the new regulations.

The main concern with burning heavy oil for heat is the pollution: When burned, these oils emit sulfur dioxide and fine particulate matter. While levels of sulfur dioxide have decreased in all heating oils due to Local Law 43 and state law, particulate matter levels are reduced only when individual buildings take action and make the switch from heavy heating oils to cleaner alternatives.

Since 2011, many buildings have made the switch to cleaner fuels such as natural gas and ultra-low sulfur No. 2 oil (ULS 2) with biodiesel blends. As of June 30, 2014, more than 4,000 buildings have completed conversions to cleaner heating fuels, 75 percent of which have been to the cleanest available fuels. This has reduced particulate matter emissions by a projected 375 tons citywide—or 50 percent of the 2011 particulate matter pollution levels.

And during the first six months of Mayor de Blasio’s term, NYC Clean Heat converted over 1,000 building heating systems to cleaner fuels resulting in a removal of 87 tons of particulate matter from the air in New York City. Nearly 800 buildings went beyond the regulation requirements and converted to biodiesel, ULS 2, natural gas, or steam.

A report from the NYC Department of Health and Mental Hygiene (DOHMH) quantifies these reductions in sulfur dioxide and fine particulate matter by comparing community-level air quality surveys carried out in 2008-2009 and 2012-2013. In this time period, levels of sulfur have dropped by 69 percent and fine particulate levels have dropped 23 percent. According to the report, the cleaner air is preventing an estimated 800 deaths and 2,000 emergency room visits and hospitalizations from lung and cardiovascular diseases annually.

Although much progress has been made, many NYC buildings continue to use heavy heating oil. High concentrations of these heavy oil buildings are in areas as diverse as the Upper East and West Sides, Upper Manhattan, and South Bronx.

Timeline for Heating Oil Conversions

If your building currently uses No. 6 oil it will need to convert to a cleaner fuel before its current certificate of operation expires and no later than June 30, 2015. The regulations were designed to balance near-term pollution reduction while minimizing costs for buildings. Here are the specifics:

  • All new boiler or burner installations must utilize one of the cleanest fuels, which may include natural gas, ultra-low sulfur No. 2 oil, biodiesel, or steam.
  • Since July 1, 2012, No. 6 oil Certificate of Operations have not been issued.  At a minimum, these buildings will be required to convert to a fuel as clean as No. 4 oil upon boiler permit renewal between July 2012 and June 30, 2015, whenever the boiler permit of the building expires.
  • All buildings must convert to one of the cleanest fuels upon boiler or burner retirement or by Jan. 1, 2030, whichever is sooner. In other words, owners of No. 4 oil-burning buildings will need to switch to No. 2 heating oil or natural gas whenever the boiler or burner is replaced by Jan. 1, 2030.

Switching to Cleaner Fuel Options

Many buildings will be able to switch to one of the cleanest fuels using their existing equipment. Others may need to replace or upgrade components of their systems. The cleaner heating fuel options are natural gas, No. 2 heating oil, biodiesel, or Con Edison steam. Eventually, a building owner using dirtier No. 4 or No. 6 oil can decide to burn only No. 2 heating oil, only natural gas, or a combination. Con Edison steam eliminates the need for a boiler or oil tank. No. 2 heating oil is 10-30 percent more expensive than No. 6 oil, and natural gas is cheaper than No. 6 oil.

Obtain cost estimates. Once you understand your conversion options, obtain cost estimates by contacting your existing fuel supplier or boiler service provider to ask how it can assist you with converting to a cleaner fuel and to obtain cost estimates. If more extensive work to your heating system is needed, you may also need to consult a licensed engineer. If you plan to seek bids from multiple contractors, make sure to submit the most detailed specifications possible and ask contractors to include pricing for all required items.

Oil to gas conversions. If you’re interested in connecting to the natural gas system you’ll need to contact Con Edison or National Grid, depending on which utility serves your neighborhood, to determine if there will be costs for connecting to their gas distribution system. It’s best to obtain cost estimates for your fuel conversion work before contacting your gas utility so that you’re ready to take action. If your building is located in Manhattan below 96th Street and are interested in converting to steam, contact Con Edison Steam.

Once you make contact, find out:

  • If your utility company can bring a gas line to your building;
  • If your utility company will pay to bring the line to your building;
  • If your building is located in a low or high gas pressure area; and
  • About the different gas rates (firm or interruptible).

If your utility company won’t pay to bring a natural gas line to your building and if you decide that you’d like to implement natural gas as a heating fuel, check the map at to see which neighboring buildings you could contact to switch to gas as well so that you can split the costs.

Oil to gas conversions are the most costly and complex. Even if you already use gas in the building for stoves, you’ll need a larger main inside the building and you might need a gas booster pump to increase the pressure. And if you’re burning only gas, you’ll also need a new burner.

In addition, the required relining of the chimney with steel or ceramic flue sealant can be costly. This is needed because gas burns cooler than fuel oil. With gas, it condenses in the stack and basically turns into acid rain, which can destroy masonry and leak fumes into the building without the proper lining.

Switching to No. 2 heating oil. If your building’s existing burner can also burn No. 2 oil, in most cases, it will require only a tank cleaning and removal of certain equipment before the building can make the switch. These two tasks can be done in just a few weeks, according to the Environmental Defense Fund. However, if a new burner is required, it most likely will take a few months to switch.

Research financing and incentives. Converting to a cleaner fuel will probably include upfront costs. You can learn more about available financing and incentives at and