Let’s be honest, most of us don’t think about our water heater until something goes wrong. It’s that silent workhorse tucked away in a closet or basement, faithfully providing hot showers and clean dishes. But when you hear a strange noise, spot a puddle, or are heading out for a long vacation, suddenly knowing How To Turn Off A Water Heater becomes the most important piece of information you need. And you need it fast.
Don’t worry, you’ve come to the right place. As the head tech here at Water Heater World, I’ve seen it all. I’m here to walk you through this simple but crucial process. Whether you have a gas or electric model, this guide will give you the confidence to shut down your unit safely and correctly, preventing potential damage and giving you peace of mind.
First, Why Would You Need to Turn Off Your Water Heater?
Before we dive into the “how,” let’s quickly cover the “why.” Knowing the reason can help you decide if a full shutdown is necessary.
- There’s a Leak: This is the most common emergency. If you see water pooling around the base of your unit, shutting it down immediately is your first line of defense to prevent major water damage.
- You’re Going on Vacation: Leaving for more than a few days? Turning off your water heater is a smart way to save energy and eliminate the risk of a leak while you’re away.
- Performing Maintenance: If you’re planning to drain the tank to clear out sediment or replace the anode rod, a complete shutdown is a non-negotiable part of the process.
- No Hot Water: If your hot water has suddenly gone on strike, turning the unit off and on again (after a short wait) can sometimes reset it. If not, it needs to be off before any troubleshooting or repairs begin.
- Strange Noises: Loud popping, rumbling, or whistling can be a sign of major sediment buildup or a failing heating element. It’s best to turn it off and call a professional.
How to Turn Off Your Water Heater: The Main Event
The process differs slightly depending on whether you have an electric or a gas water heater. Not sure which one you have? It’s easy to tell. A gas heater will have a gas line (usually a flexible metal tube) running to it and a pilot light or electronic ignition control box near the bottom. An electric heater will have a thick electrical cable running from the wall directly into the unit.
Find your type below and follow the steps. Safety first, always!
For an Electric Water Heater
Shutting down an electric model is all about cutting the power before you do anything else. This prevents the heating elements from burning out.
- Cut the Power at the Breaker Box: This is the most important step. Head to your home’s main electrical panel (or breaker box). Find the circuit breaker dedicated to your water heater. It’s usually a double-pole breaker (it’s twice as wide as the standard ones) and should be labeled “Water Heater.” Flip it to the OFF position.
- Turn Off the Water Supply: Locate the cold water inlet pipe on your water heater (it’s often on the top and may be labeled blue). You’ll find a shut-off valve on this pipe. It will either be a lever handle or a round, wheel-like handle.
- For a lever handle, turn it a quarter turn so it’s perpendicular to the pipe.
- For a round handle, turn it clockwise (“righty-tighty”) until it stops.
- Drain the Tank (Optional but Recommended for Repairs): If you’re turning the unit off for maintenance, you’ll now need to drain it. Connect a garden hose to the drain valve at the bottom of the tank and run the other end to a floor drain or outside. Open a hot water faucet somewhere in the house to let air in, then open the drain valve.
Critical Safety Warning: Never drain a water heater without first turning off the power at the circuit breaker. If the heating elements are exposed to air while energized, they will burn out in seconds, leading to a costly repair.
For a Gas Water Heater
With a gas model, your priority is to safely shut off the gas supply.
- Turn the Gas Control Knob to OFF: Look for the gas control valve on the front of the heater, near the bottom. It will have a dial with settings like “ON,” “PILOT,” and “OFF.” Press down slightly and turn the dial to the OFF position. This will stop the flow of gas to both the main burner and the pilot light.
- Vacation Tip: If you’re just going away for a while, you can often turn the dial to the “PILOT” setting. This keeps the pilot light lit but stops the main burner from firing up, saving gas. For longer trips or repairs, turning it completely “OFF” is best.
- Shut Off the Main Gas Supply (Optional but Recommended for Repairs): For added safety, you can also close the manual gas shut-off valve located on the gas pipe leading to the control valve. Turn the handle a quarter turn so it’s perpendicular to the pipe.
- Turn Off the Water Supply: Just like with an electric model, find the cold water inlet pipe and turn the shut-off valve clockwise or a quarter turn to the closed position.
Important Note on Gas: If you smell gas at any point during this process or near your water heater, stop immediately. Do not use any electronics or create a spark. Leave the house and call your gas company’s emergency line from a safe distance.
What About Tankless Water Heaters?
Also known as on-demand water heaters, these are a bit different. Since they don’t store hot water, the process is simpler.
- Unplug It or Turn Off the Breaker: Most tankless units are electric. Simply unplug the unit from the wall. If it’s hardwired, turn off the corresponding breaker in your electrical panel. For a gas tankless unit, turn the gas valve off.
- Shut Off the Water: There will be cold and hot water valves connected to the unit. Turn both the cold water inlet and the hot water outlet valves to the closed position. This isolates the unit completely.
Okay, It’s Off. Now What? Turning It Back On
So, you’ve fixed the leak or you’re back from vacation. Turning your water heater back on is basically the reverse process, but the order is extremely important.
Restarting an Electric Water Heater
- Ensure the Tank is Full: This is the most critical step. Before you do anything with the power, the tank must be completely full of water. To do this, make sure the drain valve is closed, then open the cold water supply valve. Go to the faucet closest to the heater and turn on the hot water tap. You’ll hear sputtering and hissing as air is forced out. Once you have a steady, solid stream of water, the tank is full.
- Turn the Power Back On: Go back to your breaker box and flip the water heater’s circuit breaker back to the ON position. It will take some time (often 30-60 minutes) for the water to heat up fully.
Restarting a Gas Water Heater
- Ensure the Tank is Full: Follow the exact same procedure as for the electric model above. A full tank is essential.
- Turn the Water and Gas Supply On: Open the cold water supply valve. Then, open the main gas shut-off valve on the pipe.
- Relight the Pilot: This can be the tricky part. Turn the gas control knob to the “PILOT” position. Press and hold the knob or a separate “igniter” button down. While holding it, press the red or black piezo ignition button several times until you see the pilot flame light up through the small viewing window.
- Keep Holding: You must continue to hold the control knob down for about 30-60 seconds after the pilot is lit. This heats up a safety sensor called a thermocouple.
- Turn to “ON”: Release the control knob. If the pilot flame stays lit, you’re golden! Now you can turn the dial to the “ON” position and set your desired temperature. You should hear the main burner kick on with a “whoosh” sound.
A Pro Tip from Our Lead Technician, John Carter: “I always tell homeowners to take a picture of their gas control valve and shut-off valves before they touch anything. When it’s time to turn things back on, you have a perfect reference. It’s a simple trick that has saved dozens of my clients from confusion and frustration.”
Frequently Asked Questions (FAQ)
Q: Is it bad to turn your water heater off and on?
A: Not at all, as long as you do it correctly! For short periods (like a weekend trip), the energy savings may be minimal. But for extended absences or maintenance, it’s a recommended and safe practice.
Q: How long can a water heater be turned off?
A: Indefinitely. As long as the power or gas is off, it’s simply a storage tank for water. The main concern with leaving it off for very long periods in cold climates is the risk of the water inside freezing and bursting the tank.
Q: Do I need to drain my water heater if I turn it off for vacation?
A: No, you don’t need to drain it. Simply shutting off the power/gas and the main water supply to the unit is sufficient for a vacation.
Q: What happens if you forget to turn on the water before the electricity?
A: This is called “dry firing.” For an electric water heater, the upper heating element will be exposed to air instead of being submerged in water. It will overheat and burn out almost instantly, requiring a replacement.
Q: My water shut-off valve is stuck. What should I do?
A: Older gate valves can seize up from mineral deposits. Try gently working it back and forth. If it won’t budge with reasonable force, don’t force it to the point of breaking. You may need to shut off the main water supply to your entire house and call a plumber to replace the faulty valve.
Your Go-To Source for Water Heater Knowledge
Knowing how to turn off a water heater is a fundamental skill for any homeowner. It empowers you to act quickly in an emergency, save money while you’re away, and perform basic maintenance safely. By following these steps, you can handle the situation like a pro. Remember, when in doubt, especially if you smell gas or are unsure about your electrical system, the safest move is always to call a qualified professional. At Water Heater World, we’re dedicated to turning complex problems into simple solutions for you.