It is important to check CO2 levels when installing a wood burner or any other combustion appliance. It is recommended that you install a Carbon Monoxide (CO2) tester near the appliance, and regularly test for CO2 levels in your home. CO2 testers are an inexpensive way to ensure your safety and can help alert you if there is an issue with the appliance or ventilation system. Also, you should check the batteries on the CO2 tester regularly.