Wednesday, December 12, 2012, By Erin Smith

Boston, MA – An old water heater caused a carbon monoxide leak that sickened eight people at an upscale downtown spa on Saturday, according to the business.

Exhale, a salon and yoga studio purchased a new boiler and installed carbon monoxide detectors before reopening yesterday, according to Exhale spokeswoman Kim Kiernan. She said the eight people taken to the hospital were later discharged and are now feeling well.

Problem: Defective water heater or boiler??