how to turn off tankless water heater

3 min read 06-02-2025

Tankless water heaters, also known as on-demand water heaters, offer energy efficiency and endless hot water. But knowing how to properly turn them off is crucial for safety and maintenance. This comprehensive guide will walk you through turning off your tankless water heater, covering various models and scenarios. Understanding how to shut down your unit is essential, whether for repairs, relocation, or simply preventing energy waste when away from home.

Why Turn Off Your Tankless Water Heater?

Before diving into the specifics, let's understand why you might need to turn off your tankless water heater:

Maintenance and Repairs: Turning off the unit is a necessary safety precaution before undertaking any maintenance or repair work. This prevents accidental scalding or electrical shocks.
Relocation or Moving: If you're moving and need to disconnect your tankless water heater, knowing how to properly shut it down is essential. Improper disconnection can lead to damage.
Energy Conservation: When you're away for an extended period, turning off your tankless water heater can save you money on your energy bill, especially if you have an electric model.
Emergency Situations: In case of a power outage or other emergencies, knowing how to quickly shut down your water heater is a valuable skill.

How to Turn Off Your Tankless Water Heater: A Comprehensive Guide

The process of turning off your tankless water heater varies depending on the type (gas or electric) and brand. However, the general steps are similar:

Step 1: Locate the Main Power Supply

Electric Tankless Water Heater: Locate the circuit breaker that controls your water heater. This is typically found in your electrical panel. Turn the breaker to the "off" position. Confirm the power is off by checking with a voltage tester.
Gas Tankless Water Heater: For gas units, you'll need to turn off the gas supply. Locate the gas shut-off valve, usually found near the water heater itself. Turn the valve clockwise to the "off" position. You should hear a distinct click. Verify that the gas is off using a gas leak detector.

Step 2: Turn Off the Water Supply

Regardless of whether your heater is gas or electric, you need to shut off the water supply to prevent leaks and water damage during maintenance or repairs. Locate the shut-off valves on the cold water supply lines leading to your tankless water heater. These valves are usually located close to the unit itself. Turn these valves clockwise to the "off" position.

Step 3: (Optional) Drain the Water Heater

Draining your tankless water heater isn't always necessary but is recommended before major repairs or relocation. Consult your water heater's manual for specific instructions on how to drain it safely. This usually involves opening a drain valve near the unit's base.

Step 4: Additional Considerations for Gas Water Heaters

Gas tankless water heaters require extra caution. Always ensure the gas supply is completely off before beginning any work. Never attempt repairs or maintenance on a gas unit unless you are properly trained and qualified to do so. If you are unsure, always contact a qualified plumber or gas technician.

Step 5: Turning the Water Heater Back On

To restart your tankless water heater, reverse the steps above: Turn on the water supply, then the gas (if applicable), and finally, the electrical breaker.

Troubleshooting

If your tankless water heater doesn’t turn on after following these steps, check the following:

Check the circuit breaker or gas valve again. It's possible the switch was accidentally flipped or the valve was not completely turned off.
Look for error codes. Your water heater might display error codes on a digital display. Consult your owner's manual to troubleshoot these codes.
Inspect the water supply lines for leaks. A leak can interrupt the water flow to the heater, preventing it from functioning correctly.
Check your gas supply (if applicable). If your gas supply is interrupted, call your gas company.

If the problem persists, call a qualified technician for assistance. Don't attempt any repairs yourself unless you're knowledgeable about plumbing and electrical systems.

Conclusion

Knowing how to turn off your tankless water heater is a crucial skill for every homeowner. By following these step-by-step instructions, you can safely and efficiently shut down your unit for maintenance, repairs, or energy conservation. Remember, safety is paramount, so always consult your owner's manual and, if in doubt, contact a qualified professional. Properly maintaining and operating your tankless water heater ensures years of reliable hot water.