On September 21, 2012, about 1430 mountain daylight time, a Canadair Ltd. CL-600 Challenger business jet N125PS, performed an emergency landing at the Denver International Airport due to smoke and fumes in the airplane. The two airline transport pilots, one crew member, and seven passengers were not injured. There was no reported damage to the airplane. The airplane was registered to Joda LLC, Chesterfield, Missouri, and operated by Worldwide Jet Charter LLC, Millville, New Jersey, under the provisions of 14 Code of Federal Regulations Part 135 as an on-demand air taxi. Instrument meteorological conditions prevailed for the flight, which operated on an instrument flight rule flight plan. The flight originated from Omaha, Nebraska, and was en route to Santa Monica, California. According to statements obtained by the Federal Aviation Administration, while en route to their destination, a crew member detected smoke near the galley area of the airplane. The flight crew elected to divert the flight and landed without incident. Upon landing, the crew ordered an emergency evacuation of the airplane. The airplane’s operator, Worldwide Jet Charter, did not provide an NTSB Form 6120 as requested by the NTSB investigator-in-charge. The airplane was equipped with a KC Aviation Custom Designed Water Heater, part number 444-0007, serial number 3058. The heater mat assembly was removed and sent to Bombardier, Montreal, Canada, for further examination. The assembly was examined by Bombardier under the auspices of the Transportation Safety Board of Canada. The exam revealed evidence of a loose contact pad from its original position inside of the thermostat. This allowed the pad to move within the thermostat casing. The pad was wedged itself between bimetallic strips which would keep the heating mat operating in the on position. This incident was similar to at least two other instances of heater mat overheats.