Unit freezes or is damaged after cold weather; no water flow or visible cracks

Safety first: Do not attempt to operate a unit you suspect is frozen or cracked; this can cause flooding.

Steps to check:

• Inspect for leaks: Once temperatures rise, look for water leaking from the unit or connected piping.
• Check power: Ensure power is maintained to the unit in cold weather so built-in freeze protection can operate.
• Insulate piping: Insulate exposed hot and cold water lines and consider heat tape where allowed.
• Drain unit if unused: If the unit will be off during freezing weather, follow the Rinnai manual to drain water from the heater.

When to call a professional: If damage is suspected, a technician should inspect and replace any cracked components, including the heat exchanger.