How to prevent your tankless water heater from freezing

Unlike traditional tank water heaters, which have a reservoir of hot water in them at all times, tankless water heaters do not, they only heat water as it is needed.  Unfortunately, this can make them prone to freezing when the temperature drops, especially the ones that are installed on the outside wall of a home.  We understand that a tankless water heater is a significant investment, and no one wants to be without hot water, so what can you do to ensure that your tankless water heater does not freeze and get damaged?

All tankless water heaters have anti-frost protection built into them.  As long as the unit has power, the gas is on and no valves have been shut, then the unit will be able to keep itself from freezing.  However, where we often see problems is when that unit loses power during the freezing period.  Once the unit loses power it can no longer protect itself from freezing up and when it does it will often crack water lines and heat exchangers.  If this occurs, most manufacturers will not warranty the damage because the unit lost power.  So back to the original question…what can we do to prevent our tankless water heaters from freezing?

1. Ensure the unit has power.
   - If power goes out, have a backup generator or battery backup ready to supply power to the tankless water heater.
2. Insulate any exposed water lines (such as the connection points below the tankless).
3. In the event, the tankless water loses power, and you cannot supply a backup power supply, then turn the unit off, turn the water inlet valve off, turn the gas shut-off valve to the off position, and then drain the water heater (see your manufacturer's instructions)
4. Follow your manufacturer's instructions.  Click on some popular name-brand links below:
   • Rinnai
   • Navien
   • Rheem

Did you know?

Tankless water heater manufacturers recommend their units be flushed at least once a year to eliminate the buildup of calcium and other minerals within the unit — and even more often if you have hard water. Keep your tankless water heater running efficiently by signing up for Okaloosa Gas’ Tankless Water Heater Maintenance Program.

Our Tankless Water Heater Maintenance Program includes:

• Thorough flushing of the unit
• Clean and inspect burner assembly
• No charge on labor for warranty replacements
• Technical support on Rinnai codes
• No-worry advanced scheduling with reminders

If your tankless water heater is under four years old:

Okaloosa Gas customers can sign up for our Tankless Water Heater Maintenance Program for $80* per year with a three year minimum contract. If you own more than one natural gas tankless unit at the same location, receive the second one for only $40.

If your tankless water heater is over four years old:

Okaloosa Gas customers can sign up for our Tankless Water Heater Maintenance Program once their tankless unit is inspected before qualifying for the program. If the unit passes inspection, you can sign up for the program for $80* per year with a three year minimum contract. If you own more than one natural gas tankless unit at the same location, receive the second one for only $40.

Otherwise, you can elect to have the tankless system de-limed for our regular price of $100. If you own more than one natural gas tankless unit at the same location receive the additional units for $45 each.

*Maintenance program does not qualify for homes that have a circulating system.

Call 850-729-4700 or fill out the Tankless Water Heater Maintenance form to schedule an appointment.

Water Heater Maintenance Form

Please complete the form and we will respond to your request within 24-hours of normal business operating hours.