Yes, turning off your water heater at night can save money on your energy bills, especially if you have an older, less efficient model or if your household uses very little hot water overnight. The savings depend on the type of water heater, its age, and your hot water usage patterns.
Understanding Water Heater Energy Consumption
Your water heater is a significant energy consumer in your home. It works by heating water and then maintaining that temperature, which requires continuous energy input. This process is known as standby heat loss.
What is Standby Heat Loss?
Standby heat loss occurs when your water heater expends energy to keep the stored water hot, even when no hot water is being used. This happens because the tank isn’t perfectly insulated, and heat gradually escapes into the surrounding air.
- Older models typically have poorer insulation, leading to higher standby losses.
- The longer the water sits in the tank, the more heat is lost.
- This constant reheating contributes to your electricity or gas bill.
How Much Energy Does a Water Heater Use?
The amount of energy a water heater uses varies greatly. For electric water heaters, it can account for 15-20% of your total electricity bill. Gas water heaters have similar proportional energy costs.
- A typical electric water heater might use between 3 to 5 kWh per day just to maintain temperature.
- Gas water heaters can lose a significant percentage of their heat through the flue.
Does Turning Off Your Water Heater at Night Save Money?
The short answer is yes, it can, but the extent of savings varies. By turning off your water heater, you eliminate standby heat loss during the hours it’s not in use. This prevents the unit from constantly reheating the water.
When Turning It Off Makes Sense
- Infrequent Overnight Use: If your household goes through a long period without using hot water, such as overnight, turning it off is beneficial. This is especially true for families with early risers who might not need hot water immediately.
- Older, Inefficient Models: Older water heaters are less insulated and lose heat more quickly, meaning they work harder to maintain temperature. Turning these off can lead to noticeable savings.
- Vacation or Extended Absences: If you’re away from home for several days or longer, turning off the water heater is a clear way to save energy and money.
When It Might Not Be Worth It
- New, High-Efficiency Models: Modern water heaters often have much better insulation and smart features that minimize standby losses. For these units, the energy saved by turning them off might be minimal.
- Constant Hot Water Demand: If your household uses hot water frequently throughout the night or very early morning (e.g., for overnight medical needs, early shift workers), turning it off might lead to inconvenience.
- Time and Effort: For some, the effort of turning the unit on and off daily might outweigh the small savings.
Types of Water Heaters and Their Savings Potential
The type of water heater you own significantly impacts potential savings.
Electric Water Heaters
Electric resistance water heaters are common and can be easily turned off using a switch or breaker. The savings come directly from stopping the electrical current that maintains the water temperature.
Gas Water Heaters
Gas water heaters can also be turned off, usually by adjusting a thermostat dial to the "pilot" or "off" setting. This stops the gas flow to the main burner, though the pilot light may remain on in some models.
Tankless (On-Demand) Water Heaters
Tankless water heaters heat water only when it’s needed, meaning they have virtually no standby heat loss. Turning these off at night will not yield significant savings, as they aren’t actively heating water when not in use.
How to Turn Off Your Water Heater
The process varies slightly depending on whether your water heater is electric or gas.
Turning Off an Electric Water Heater
- Locate the Breaker: Find the circuit breaker that controls your water heater in your home’s electrical panel. It will usually be labeled "Water Heater."
- Flip the Switch: Turn the breaker to the "off" position.
- Alternative (If Accessible): Some electric water heaters have an external power switch. You can flip this to the "off" position.
Turning Off a Gas Water Heater
- Locate the Gas Control Valve: Find the dial on the front of the water heater’s gas control valve.
- Turn to "Pilot" or "Off": Rotate the dial to the "pilot" or "off" setting. If you select "pilot," the pilot light will remain lit, consuming a small amount of gas. Setting it to "off" extinguishes the pilot light.
- Note: Be sure to follow the manufacturer’s instructions for relighting the pilot if you turn it off completely.
Calculating Potential Savings
Estimating your exact savings can be complex, but you can get a rough idea.
- Identify Standby Loss: Research the standby heat loss percentage for your specific water heater model. Manufacturers often provide this information.
- Estimate Daily Usage: Track your hot water usage over a few days to understand how much is used overnight.
- Energy Cost: Know your electricity or gas rate per kilowatt-hour (kWh) or therm.
Example Scenario: Let’s say your electric water heater loses 10% of its stored heat daily due to standby loss, and you have a 50-gallon tank. If you turn it off for 8 hours overnight, you prevent a portion of that loss. If your energy cost is $0.15 per kWh and your heater uses 4 kWh per day for standby losses, saving 25% of that loss by turning it off for 8 hours could equate to a small daily saving.
| Water Heater Type | Standby Loss Potential | Savings Potential (Overnight Off) | Convenience Factor |
|---|---|---|---|
| Older Electric | High | Moderate to High | Moderate |
| Older Gas | High | Moderate to High | Moderate |
| Newer Electric | Low | Low | High |
| Newer Gas | Low | Low | High |
| Tankless (On-Demand) | Negligible | Negligible | Very High |
Alternatives to Turning Off Your Water Heater
If turning your water heater off completely seems inconvenient, consider these alternatives.
Use a Timer
A water heater timer can automate the process. You can program it to turn off during specific hours (like overnight) and turn back on before you typically need hot water. This provides savings without manual intervention.
Install a Timer
- Electric Water Heaters: Timers are readily available for electric models and easily integrate with the circuit breaker.
- **Gas Water Heaters