Leaving a water heater on all day is normal and expected for most residential tank-style heaters, which are designed to keep a constant supply of hot water ready. While it results in steady, standby energy loss, the main risks occur only if the water supply is shut off while the heater remains active.
Yes, it is perfectly okay and, in fact, recommended to leave your water heater on for everyday use. Constantly reheating a tank of cold water wastes more energy and causes more wear and tear than maintaining a steady temperature.
Overheating risks: The heater elements or burners keep heating with no water to absorb the energy. Pressure issues: Valves may become stressed, leading to leaks. Costly heater repairs: Damage may require professional heater repair or complete replacement.
To effectively control Legionella bacteria, the CDC recommends storing hot water at 𝟏𝟒𝟎∘𝐅 (𝟔𝟎∘𝐂) and maintaining circulating hot water above 𝟏𝟐𝟎∘𝐅 (𝟒𝟗∘𝐂).
Potential Risks of Leaving It On
Leaving your water heater on during a winter vacation can pose several risks, including leaks and unnecessary energy consumption. Water heaters, especially older models, can develop leaks over time, which may go unnoticed if you're away. This can lead to water damage and costly repairs.
This isn't about draining the tank or water being in the tank— it's about the loss of pressure and introduction of air during the break. That's why turning the breaker off until water pressure is fully restored and the air is flushed out is a safe, precautionary step!
Shut Off The Water Heater
If you have a gas water heater, you can turn the heater off at the source and shut off the gas valve. If you have an electric heater, it can be turned off at the breaker. Once off, you can open the valve or spigot on the water heater to drain the water into a pail or bucket.
The first signs of Legionnaires’ disease typically appear 2 to 14 days after exposure to Legionella bacteria. Early symptoms are often flu-like and include:
Run your shower for 5 to 10 minutes to flush out stagnant water. If the property has been vacant for several weeks, some experts recommend running it for up to 20 minutes.
Domestic water heaters, particularly electric devices, can certainly be contaminated by Legionella. In Quebec, a study of 211 homes (178 electric water heaters, 33 oil or gas water heaters) found Legionella contamination in 40% of electric water heaters.
To prevent catastrophic leaks while you are away, turn off your home's main water supply valve, open a high faucet to relieve pressure, and turn off your water heater. This simple routine takes just a few minutes and protects your home from severe water damage.
As a precautionary measure and to prevent damage and potential hazards, it's always best to turn off your water heater (both the heating element/gas supply and the water supply valve to the heater) if the main water supply to your house is shut off.
Typically, if I turn off the water to my water heater, I would also turn off the power to the water heater. Water turned off won't prevent issues. The pipes would have to be DRAINED to avoid an issue. Otherwise it's just water sitting in the pipes that is going to freeze.
Risks of Leaving Your Geyser On
Overheating can lead to dangerous pressure build-up inside the tank. In extreme cases, this can result in leaks or even severe malfunctioning.
If a standard showerhead is fitted, it will use around an extra half a gallon each minute, accounting for a 25-gallon emittance every 10 minutes, or 50 gallons throughout a 20-minute shower. *1 gallon = 4.54 litres.
Signs a Water Heater is Going Bad
Legionella bacteria in water can be effectively eradicated using high temperatures, chemical oxidizers, or specialized physical sterilization.
An unused shower poses a risk for Legionella growth because stagnant water in pipes creates an ideal environment for bacteria to multiply. You catch Legionnaires’ disease by breathing in aerosolized water droplets. To safely clear the system, you should flush the plumbing and disinfect the showerhead.
Legionella bacteria can multiply and reach dangerous levels in water within a matter of days to a few weeks, depending entirely on the environmental conditions.
Legionnaires' disease is usually contracted by breathing in small, contaminated water droplets (mist or aerosol) that contain Legionella bacteria. It is not spread person-to-person.
Symptoms of a Legionella infection typically appear 2 to 14 days after exposure to the bacteria, with an average incubation period of 5 to 6 days.
Between 77∘F and 113∘F (25∘C to 45∘C), Legionella bacteria thrive and multiply.
To compensate for heat loss, you may need to slightly increase the water heater's thermostat setting during winter. The recommended temperature is between 120–140°F for most households.
If you have an electric water heater, it is recommended that you shut off the power and the cold water supply to the water heater if you are going away for any length of time. You will save electricity and limit any damage in case the tank leaks.
Q: Can a water heater freeze in a cold garage? A: It's possible, especially in very cold climates. To prevent freezing, ensure proper insulation on pipes, choose a model rated for cold environments, and consider installing a unit with built-in freeze protection.