Review on Kidde Hardwired Smoke & Carbon Monoxide Detector with Battery Backup & Voice Alert - Interconnect Combination Alarm by Joseph Quade

I installed them last week. It was the first time I had smoke detectors with carbon monoxide detection. After a week of normal operation, it started at 4 a.m. today. I turned them off manually and they went off again. I called the fire department who arrived with a portable carbon monoxide detector and confirmed that our water heater was not working and was spewing out lethal levels of carbon monoxide. The gas company has shut down our boiler and we are waiting for service. It saved our lives.