Walnut Creek, CA Building Safety: Carbon Monoxide Detectors (2026)

California's Carbon Monoxide Poisoning Prevention Act of 2010 (Health & Safety Code §17926 et seq.) was phased in between 2011 and 2013 and applies to every Walnut Creek dwelling that has a fossil-fuel-burning appliance (gas furnace, water heater, stove, fireplace, or wood/pellet stove) or an attached garage. Required locations mirror smoke alarm placement: outside each sleeping area in the immediate vicinity of bedrooms, on every level of the home including basements, and per manufacturer instructions. Alarms must be listed to UL 2034 (or the newer CSA 6.19-01) and may be combination smoke/CO alarms if compliant with both standards. For new construction and permitted remodels, the California Residential Code §R315 requires hardwired CO alarms with battery backup, interconnected with other alarms. Existing single-family homes may use battery-operated or plug-in alarms; like smoke alarms, replacement units must be 10-year sealed battery models. Sellers of single-family homes must include CO alarm certification at transfer, and residential landlords must install and maintain alarms in compliance with HSC §17926.1. Violations are an infraction punishable by a warning followed by a $200 fine per offense. Failure in rental property can also trigger tenant remedies. Walnut Creek code enforcement inspects for CO alarms on complaint-driven cases and as part of any permitted work involving bedroom additions, garage conversions, or HVAC replacement.