A U.S. appeals court in Washington, D.C., has granted an emergency motion delaying the regional furnace efficiency standards that were due to take effect today.

The Air-Conditioning, Heating and Refrigeration Institute, an HVAC manufacturers group, had requested the stay due to the uncertainty created by a proposal to settle a lawsuit over the issue. That settlement has yet to be accepted by the court.

Under regulations first announced in 2011, most indoor natural gas furnaces sold and installed after today’s date in 30 Northern states were to have an annual fuel utilization efficiency rating of at least 90 percent. The American Public Gas Association; Air Conditioning Contractors of America; and the Heating, Air-Conditioning and Refrigeration Distributors International filed a federal lawsuit challenging the rules.

In January, the U.S. Department of Energy agreed to scrap the regulations and begin a new round of rulemaking. While it waits to see if the court accepts the settlement, the Energy Department recently issued an “enforcement policy statement” saying it would proceed as if the settlement had been approved.

If the appeals court does not OK the settlement, the issue is expected to go to trial, the ACCA said.