Noritz water heater installed outdoors will not operate in cold weather; visible ice or frost on piping or unit.

Safety first: Do not attempt to force operation if you suspect frozen pipes; they may burst. Turn OFF power and gas. Close water supply to the heater.

Steps to check and correct:

• Thaw safely: Allow the unit and piping to thaw naturally or use gentle indirect heat (space heater in the room). Do not use open flames or high-heat devices on pipes.
• Inspect for leaks: Once thawed, slowly open the water supply and check for leaks from split pipes or fittings.
• Check freeze heaters: On Noritz outdoor models, verify that freeze protection heaters are intact and wired correctly. This typically requires a technician.
• Insulate piping: Add insulation and heat trace (if needed) to exposed water and condensate lines per Noritz and local code requirements.