Thermostat Recycling Corp. said 2014 was a record year for the organization — it collected the most mercury-containing thermostats in the group’s 17-year history.

More than 203,000 thermostats were taken in at member wholesalers to be recycled — a 12 percent increase from 2013. More than 9 tons of mercury have been kept out of landfills since 1998, the organization said.

“This is a big achievement since all major manufacturers of mercury thermostats ceased production by 2009, meaning the amount available to recover continues to decline,” said Thermostat Recycling Corp. Executive Director Mark Tibbetts. “These gains help us make a greater positive impact on the environment thanks to the continued dedication of our collection partners.”

 The HVAC construction industry and its distributors and contractors were responsible for 78 percent of all mercury collections, TRC said.