The short answer is yes, as long as you don't mind using cold water. Shutting off the input to your water heater will not affect your home's main water supply. You can still run appliances like your washing machine or dishwasher, flush your toilet, and use your shower, sink, or garden hose.
A tank water heater keeps a fairly hefty reserve of heated water, but the water is only going to stay hot for so long, maybe an hour or two, with the power keeping its element from doing its job. So yes, if you have a tank water heater and the power went out recently, you're probably good to take a shower!
Your water heater may be turning off because it is short-circuiting or because it has other electrical problems. Such damage may have developed from water damage, impact or wear-and-tear. This is also a problem that's better left to the professionals.
How long will a hot water heater stay hot without power is a common question among users of hot water. Actually, the answer is 60-70 minutes (for a gas tank water heater) 120 minutes (for an electric tank water heater).
It's generally best to avoid turning your water heater off too regularly. Some homeowners try to save money by switching off their water heaters when they don't need them, but the savings are unlikely to be significant enough to justify the additional wear and tear on your machine.
Electric Heater
Ideally speaking, an electric water heater takes around 60 to 80 minutes to release hot water with a tank capacity of 40-gallon. If the tank capacity is 80-gallon, the recovery time can be more than two hours.
Your water heater has a tank that contains water. As long as you don't use the water, it stays in the water heater (this depends on the type of water heater). If, for any reason, the water levels fall in the tank, then it's best to turn off the water heater.
Turning off the source of the heat (gas, electric) while you're away will not damage your water heater.
In the average home, the water heater will run for about three hours each day. Total run time can range from one to two hours for new tankless water heaters to five or more hours for older tank style water heaters.
Generally speaking, a gas water heater should not be turned off unless you are leaving the house for an extended period of time. Even then the better choice for gas water heaters is to just turn the temperature down. In fact, many water heaters have a “vacation” setting on the temperature control.
It heats the water with a burner at the bottom of the tank. The burner turns on whenever the standby water dips below the desired temperature or new water is pumped in to replace any water that's being used. For a tank water heater, water is always being heated or kept hot.
Next, touch the water heater's temperature-pressure (TP) relief valve and the hot water outlet pipe above the water heater (see water heater diagrams above) to see if it's warm or cold. If you feel warmth, your water heater is probably working.
It's generally a good idea to drain your water heater at least once a year, according to both BobVila.com and The Family Handyman. If you live in an area with hard water, though, Angie's List says you may need to drain it more frequently.
How Long Can You Turn Off Water to a Toilet? Like turning off your toilet's water for a night, it's safe to do so for a week. While you can keep your toilet water off for as long as you'd like, we wouldn't recommend it unless you have a problem with your toilet's plumbing system.
While frequently turning on and off the water can cause too much pressure to be put on the water pipes, turning it off doesn't harm the system. Locate the mains water supply valve in your house, which may be in the basement or in a crawl space.
Many homeowners ask us if they should turn off their water heater between uses to save money. Our professional answer after crunching the numbers? No, unless you're going on vacation for a month or longer, you shouldn't turn off your water heater.
For Electric Water Heaters
But if you have an electric heater, here's some good news: you don't need to keep them switched off during summers. Your kitchen and dishwasher need warm water to run properly. You don't have to use hot water for showers but it's excellent for cleaning purposes.
The average adult uses about 10 gallons of water per shower (at a rate of 2 gallons of water per minute). If you assume that an 80-gallon tank has about 55 gallons of hot water to dispense before refilling, that means you have 27 or so minutes of total shower time before running out of hot water.
How Long Will It Take to Get Hot Water Again? The average gas heater takes between thirty and forty minutes to heat a full tank of water. The exact time depends on the capacity. For comparison's sake: An electric heater takes at least an hour, usually up to 80 minutes, to warm up.
The Pilot Light Is on But No Hot Water
Luckily, it's usually an easy fix: Just ensure the unit's gas valve is turned all the way on. (No need to touch the gas knob that controls the pilot light itself, since the pilot is working.) If this doesn't fix the issue, your unit may have a faulty thermocouple.
Because of its heavy workload, it is important to keep an eye (or ear) on how the water heater is functioning. While it is not uncommon for a water heater to make noise, sounds such as humming, knocking, screeching, or tapping should be addressed to rule out the need for repairs or replacement parts.
Sediment Build-Up
As the particles collect on the bottom of the tank, the water heater can't effectively heat your water, resulting in lukewarm water only. To resolve this issue, open the drain valve on your water heater and see if there is sediment. The water will not be clear if there is sediment build-up.