Best practices: Turn water heater off at night, on in the morning?

If you’ve wondered about the right way to use your water heater, in this video Gary Bunzer, the RV Doctor, answers a question from a viewer of a recent live webcast about whether it is best to leave an electric water heater on all the time or just turn it on when hot water is needed.  Subscribe to the FREE weekly RV Travel newsletter for more of what interests RVers.



7 Thoughts to “Best practices: Turn water heater off at night, on in the morning?”

  1. RVTraveler

    Sorry, But I have to disagree with this video assessment and here is why…

    1st, there is the electricity cost. The water heater will run off and on all night long to keep the water within a few degrees range. This will vary with the weather as temps get colder. Now, if you are in the park on a nightly basis and there is no additional cost for electricity (Parks build this into the nightly rate), then by all means, let it run all night.

    2nd, the element has a fixed resistance and amperage load. It does not vary with water temperature. It can be a fresh cold tank or it can be a warm tank in need of a “top off”. The resistance of the element stays the same. It’s about time duration. Either shorter bursts of wattage or longer bursts of wattage. An element does not “instantly” become hot. It takes a certain mount of time to build up heat once it is turned on and hot water is called for. So again, from the point of “time”, this makes no difference on whether the heating element lasts longer or not.

    3rd, the biggest contributor to water heater element failure is manufacturing quality and/or corrosion.

    Starting with manufacturing quality…It depends on the materials that the element is made from. There are not that many different manufacturers, so product quality will be a mute point. You get what you get.

    Then corrosion will be the real deciding factor. Do you have hard water or soft water? Is the element sealed to protect from water intrusion? In hard water, minerals attach the surface of the element and the tank. That’s why we use anode rods (Magnesium, aluminum, aluminum zinc, zinc – each have a purpose). The anode rod helps to protect other parts of the water heater (including the element). If you have the proper rod and perform your maintenance routinely, you will have an element that lasts longer.

    So, I’m with the husband in this case. turning on the water heater when it is needed would actually make the element last longer and save electricity (ultimately money). Use it when you need it. Turn it off when you don’t. On average, it will take about 15 minutes to warm up the water. To reduce that time, turn on the propane side at the same time. You’ll have hot water in 5-7 minutes (and if you are still not convinced that the element is not damaged each time you have it on, then by using propane, this will reduce the amount of time that the element is on).

    Now, if only the RV industry would install a “timer” on the water heater…Then, you could have it automatically come on and off at hours of convenience. That save money all the way around…try it at home and you will see that you can save $50 to $80 or more a month on your electricity…How do I know? I have one! I paid the bills before and now after installing the time clock!

    1. Roger Marble

      RV Traveler. I have an “add-on” electric heater to my 6 gal hot water tank. I included a 110V manual electric timer. The heater is rated 4 amps and the timer switch is rated 10 amp. Since it is a manual spring wound timer it will shut off. This doesn’t respond to the original question but my hot water tank is well insulated so doesn’t get “cold” by morning. I find that by the time the coffee is done I have water hot enough to wash up in. If I am in hurry I can turn on gas and electric and have plenty of hot water in just a few minutes.

  2. Booneyrat

    I agree with RV Traveler in his analogy. Another big problem,as stated,is hard it is wise to invest in a portable water softener which will reduce the amount of scale buildup inside your water heater,as well as help protect the plumbing in your RV. We have all seen the calcium buildup on faucets and toilets, a properly maintained water softener will stop most of that,especially when traveling in the American Southwest where hard water is prevalent.

  3. Bob Difley

    Thanks RV Traveler for sharing the benefits of your personal research. Something to think about – and not a difficult tweak to the system.

  4. Bill

    The fallacy with RVTravellers’ argument is that we don’t know how long the element needs to run during the night. Yes, the element uses a little electricity heating itself up, but that power still goes into heating water since the element starts at the same temperature as the water. So if the tank is insulated well enough that the element only comes on for a minute fifteen times a night, it will use the same amount of electricity as if it runs for fifteen minutes heating cold water in the morning. Using the propane to heat the water faster does not save you money since no campgrounds include propane in their rates. As to corrosion, most chemical reactions do proceed at faster rates at higher temperatures, but if you are replacing the anode every year anyway that doesn’t matter either.

  5. Paul

    I agree with this suggestion if you have an electric hot water heater. But in our case our hot water heater is gas only so I don’t see a need to keep the hot water switch on during the night. All it is doing is draining my LP tanks which I have to pay to have re-filled. We don’t camp when we have to worry about freezing temperatures. And the gas will heat up the water pretty quickly in the morning once turned back on.

    1. Kevin

      Same here. I turn my propane water heater on only when needed. Usually this is about 15 minutes before a shower. I turn it off again about 30 minutes after finishing my bathroom rituals. The water is still hot many hours later. I’ve noticed this cuts my propane usage nearly in half.

Comments are closed.