Yes, you can turn off the water supply to your house without turning off your water heater. However, you should not leave the water heater powered on while the main water supply is shut off.
If the main water supply is off, the tank might run dry. If the heater keeps running without water, the burner can overheat and damage the unit. This can lead to expensive repairs or warrant a complete water heater replacement.
Shutting off the water supply does not immediately affect the water heater, but you must turn off the water heater's power source (breaker or gas valve). If the tank empties and continues to heat, the elements will burn out, potentially causing a fire or damaging the unit.
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.
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.
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.
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.
Signs a Water Heater is Going Bad
Yes, you can shut off the water to your house from the water heater, but doing so only stops the flow of hot water. Cold water will continue to flow to your toilets, sinks, and outdoor spigots.
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.
When your water is shut off, you must turn off your water heater to prevent the heating elements from "dry firing" and burning out. For electric heaters, switch off the dedicated circuit breaker. For gas heaters, turn the control dial to the “Off” or “Pilot” position.
Only heat the hot water twice a day
Try heating the water for an hour in the morning and an hour in the evening. Start the water heating about an hour before you need it. For example, if you shower at 08:30, start heating the water at 07:30. If you wash up in the evening at 19:30, then start the water heating at 18:30.
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.
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.
Electric hot water heaters (right) have the heating element slightly above the bottom of the heater and because hot water rises, water at the bottom of the tank can be a cooler temperature that is optimum for Legionella growth.
Between 77∘F and 113∘F (25∘C to 45∘C), Legionella bacteria thrive and multiply.
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.
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.
Legionella bacteria primarily cause two distinct illnesses, collectively known as legionellosis:
Yes, shutting off your main water valve can affect your water heater if you do not also turn off the power (breaker) or gas supply to it. Leaving it on can cause the tank to "dry fire," damaging heating elements or ruining the tank, especially if water drains back into the pipes.
The "135-degree rule" in plumbing states that the total (aggregate) horizontal change in direction for a drainage pipe—specifically trap arms—cannot exceed 135 degrees between the P-trap and the vent. Exceeding 135 degrees (such as using three 45-degree bends or a 90 and two 45s) requires a cleanout because sharp turns hinder flow and cause clogs.
Even when you're not home, water is running through your house. Sometimes a water pipe fails at the toilet or washing machine and causes water to pour out. If you are not home, this can cause major flooding and severe water damage.