You’re getting ready for a summer trip, bags packed, thermostat adjusted, mail paused. But one thing homeowners often forget is their water heater. Should it stay on while you’re away, or is it better to shut it off?
At Hard Knox Plumbing, we talk to Knoxville homeowners every year about this. The truth is, your water heater doesn’t need to keep running when no one’s home using hot water. In fact, leaving it on could cost you extra money, or worse, cause a problem while you’re gone.
Why This Matters More Than You Think
A water heater doesn’t stop working just because the house is empty. It continues to heat and reheat water to maintain the set temperature. That’s wasted energy, and it adds to your power bill for no reason.
More importantly, if your heater is already aging or dealing with mineral buildup—a common problem in Knoxville, it may be at higher risk of failure. A slow leak or pressure valve issue while you’re away could lead to serious water damage.
If your trip lasts more than three days, it’s worth adjusting your system to save energy and avoid any problems.
When It’s Best to Turn It Off
For most tank-style water heaters, turning the system off or setting it to “vacation” mode before leaving for a week or more is a smart move. These systems use energy even when no one is home. By turning them off at the breaker (electric) or setting them to pilot mode (gas), you reduce wear and energy costs.
You can also shut off the cold water valve going into the tank to prevent added pressure while you’re away. For trips longer than two weeks, some homeowners choose to drain the tank as well.
What If You Don’t Need to Shut It Off?
If you’re gone for just a couple of days, there’s no strong reason to shut it off completely, especially if you have a tankless water heater, which only runs when hot water is needed. Many newer models also offer a low-energy or vacation setting, which lowers the water temperature without fully turning off the unit.
Homes with certain plumbing setups, such as attic installations or systems prone to airlocks, may benefit from keeping the heater in low mode rather than shutting it off. If you’re unsure which option is better, we’re happy to take a look before you leave town.
How to Handle It Safely
If you decide to turn off your water heater, don’t just unplug it or flip a random switch. Do it the right way to avoid issues when you get back. Electric models should be turned off at the breaker. Gas units can be dialed down to “vacation” or “pilot.”
For added peace of mind, shut off your home’s main water valve. That way, even if something does go wrong, no water will continue flowing into your system. You might also consider installing a smart leak sensor, which alerts you if anything starts leaking while you’re away.
Avoid These Common Mistakes
Many people think it takes more power to restart a heater than it does to leave it on. That’s not true with modern systems. Others think they can safely shut off the main water supply and leave the heater running, but that can lead to pressure buildup and damage.
Even tankless systems aren’t completely hands-off. If you haven’t descaled yours recently, now is a good time. Hard water is a common issue in Knoxville, and it can shorten the life of your system.
What We Recommend
If you’re going away for more than three days, we recommend turning your heater off or using its vacation setting. That simple step can save money, prevent problems, and help your system last longer.
And if you’re unsure what kind of heater you have or how to manage it safely, call Hard Knox Plumbing. We’ll take a look at your system, help you shut it down if needed, and even check your shut-off valves while we’re at it.
Plan Ahead for Future Trips
Want to be fully prepared next time you leave town? Here are a few smart options:
- Install a smart leak detector that alerts your phone
- Schedule regular plumbing maintenance before long trips
- Upgrade to a heater with vacation mode or remote monitoring
FAQ: Water Heater Tips Before Summer Travel
Do I need to shut off my heater if I’m gone for just two days?
No. For short trips, it’s fine to leave it on or use a low setting.
Will turning off my heater cause damage?
Modern heaters are designed to be turned off safely. There’s no risk as long as it’s done properly.
In case your water heater is presenting damage, check how we can help you solve it.
How long does it take to reheat the water when I return?
Most systems will reheat in 30–60 minutes, depending on the model and tank size.
Should I drain the tank too?
Only if you’ll be gone for more than two weeks, or if your system is older and more prone to leaks.
Learn more about water heaters here
Can I leave the heater on and just shut off the main water valve?
That’s not a great idea. If water stops flowing in and your heater keeps running, it can cause pressure issues. Always adjust both together.
Ready to Leave Town Without Worry?
Give Hard Knox Plumbing a call before your next trip. We’ll help you prep your system the right way so you can relax and enjoy your time away.
- Call now to 865.381.7486 to schedule a pre-trip inspection
- Request a quote today clicking here
- Emergency plumbing service available 24/7 throughout Knoxville
Your water heater will be in good hands, just like your home.