Carbon Monoxide Alarm Reveals Refrigerant Leak in Southwest Side Home

Ladder 7 responded to a single-family residence following a report of an activated carbon monoxide (CO) alarm. Upon arrival, crew members received immediate positive alarms for CO on their Sensit Gold G2 monitors.

Ladder 7 systematically searched the home and successfully ruled out several potential gas- and fuel-burning appliances as the source, including the water heater, oven, stove, clothes dryer, and furnace. Madison Gas & Electric (MGE) was requested to the scene to assist. 

While awaiting MGE's arrival, the homeowner informed the crew that the alarms had begun sounding immediately following the installation of a new central air conditioning and furnace system.

Firefighters ventilated the home to clear the air. During this time, MGE arrived and initially obtained the same elevated CO readings as Ladder 7 had. However, MGE applied a charcoal filter to their air monitor and all readings cleared. This indicated to responders that the problem was not a natural gas or carbon monoxide leak. 

Ladder 7 requested assistance from Engine 7, which responded to the scene with additional specialized equipment. The equipment confirmed the absence of CO and instead determined there was a leak of refrigerant from the newly installed air conditioning and furnace system. 

The heating and air conditioning system was promptly shut down, and the installation company was contacted to return and repair the leak. The installation company was expected to make repairs later that evening.

Atmospheric levels inside the home remained low following ventilation. With the HVAC system isolated, firefighters instructed the homeowner to contact emergency services immediately if the household CO detectors reactivated.