What to Look For In a Tankless Water Heater 10834

If you’re considering upgrading to a tankless water heater or purchasing one for an RV, you’re likely already aware of the numerous benefits over the traditional storage-tank model.

how a tankless water heater works

For one thing, tankless water heaters, also known as demand-type water heaters, are more energy efficient because there is no heat loss from standing water. Thus with no cumbersome tank of water, tankless water heaters are much smaller, and have less risk of spillage, avoiding potentially thousands of dollars in property damage.

Of course, the most compelling benefit is the comfort factor. Nothing is worse than needing a nice hot shower on a cold morning only to realize your water is only lukewarm and getting colder. Now you’ll have to wait another hour or two for your shower, and all because your water heater from the 1990s has to refill.

But before you rush to purchase your own ticket to heating water in the 21st century, there are a few key things you’ll want to consider before bringing your own tankless water heater home and what criteria to use when selecting the right model:

Water Usage

You will want to have at least a ballpark figure of your water usage before you begin shopping for a tankless water heater. Here is a quick reference for basic water-consumption of appliances:

  • Toilet: ½ –  gallons per minute
  • Bathtub: 2 –  4 gallons per minute
  • Shower: 1 ½ – 3 gallons per minute
  • Kitchen Sink: 1 – ½ gallons per minute
  • Dishwasher: 1 – 3 gallons per minute

When choosing a regular water heater, you might need to consider how often you might use these appliances in one day, however with a tankless water heater, the more important question is how often you think you might use multiple appliances all at once. Tankless water heaters can provide on-demand heating of water anywhere from two gallons a minute to an incredible six gallons per minute, depending on the model.


While one of the benefits to a tankless water heater is that there is less storage space required, you still want to make sure you have chosen an area for it that can be easily connected You can install your tankless water heater to the outside of your house or RV as well. Even if you live in an area that regularly drops below 0 degrees Fahrenheit or you are attaching your tankless water heater to a recreational vehicle sometimes parked in freezing climates, all you need is an anti-freeze kit that attaches onto your unit. Making sure your install location is important, as there may be certain codes or regulations regarding ventilation.

Cost & Rebates

Of course, when considering what model to buy, or whether to upgrade at all, it’s important to consider your unique needs and financial situation. A tankless water heater may cost slightly more than repairing your current water heater, however, you need to factor in the long-term savings in energy costs.

When you are ready to purchase, don’t forget to check if there are any tax credits or rebates in your state. You can get up to $300 from the federal government alone for a gas-powered tankless water heater if it meets efficiency requirements.

Electric or Gas

Depending on where you live and what electric grid you are on, either a gas or electric hookup may be cheaper or more expensive. Gas-powered tankless water heaters are on average less expensive per unit and have slightly higher flow rates.

While some tankless water heaters come with electric hookups, many find that propane-powered versions are an easier installation and that occasionally having to replace the propane is well-worth the increased rate of flow in gas units. This is because even though tankless water-heaters provide more reliable on-demand heating, they can still be stretched too far (especially the electric variety) if you are running multiple showers, laundry, and dishwasher all at the same time.


While we all wish we were a little bit handier, for those less mechanically inclined, a tankless water heater is a much simpler appliance to maintain than a giant, pilot-lit tank of water. When purchasing a tankless water heater, make sure you go with one that has a display you know you’ll be able to operate.

If you need hot water for a shower in your RV, you may be able to avoid purchasing an entire home system. Many find that a simple portable tankless water heater can make all the difference at a fraction of the cost.

Your Peace of Mind

So whether you’re looking to heat your RV, make your family stop fighting over showers, lower your monthly bills, or you just want to be a little more energy efficient in your daily life, check out a tankless water heater that’s right for your life.

If you have any questions or concerns, leave them below!


  1. Great information to have on the front-end of the purchase of a tankless water heater. I’ve been considering this purchase for some time and this information proved valuable in determining type and size, as well as accessory equipment (had never heard or been informed of anti-freeze kits in previous research).

    Thank you

    1. I installed mine outside my food truck and just ran I line to the propane tank already on board with shut off valves. Water was easy. They come with hoses. I hooked one up in my driveway to my house Hose and propane tank to check. Worked great. I could shower in driveway. Didn’t but could have

  2. Tankless are fine, but there is a major problem – they waste water. It takes a considerable volume of water before the hot water is dispensed. If you are dry camping this wasted water could become a serious problem. We have one but I am not sure I would replace it if it failed.

    1. How is this , because if it is installed in the same placement as tank type it still travels through the same lenth of pipe, and it is heated at the same point, so something must not be working correctly.

  3. I would encourage anyone interested in a tankless water heater for their RV to do a lot of research. My new (2015) motorhome came with a tankless water heater. My wife and I both hated it. I replaced that tankless with a good old-fashiioned 6-gallon tank type, and now we’re both happy again. I understand now that the newer tankless water heaters have some of the issues worked out, but even so, you will very likely waste more water with a tankless, thereby filling the gray tank faster, and use more electricity also. If your off the grid, and have a small RV, water management is much more important than saving the propane it takes to heat up your tank water heater.

    1. Amen, just got a new rv with thankless Girard, hate it, wastes all sorts of water to get hot every time you interrupt the flow

  4. What are the possibilities of a combination solar/propane for my fifth-wheel. I’m considering a similar unit to replace the gas water heater in my home.

  5. I agree completely with Jason B. Our new 2015 class c motor home came with a tankless (we call it thankless) water heater. When taking a shower, the water temperature varies from bone chilling to scalding. there is no way to keep a constant reasonable temperature. We have tried many suggestions, and tips from several sources over the last 2 plus years but to no avail. Our previous 2 motor homes had the standard tank type water heaters. We never had a problem with excessive propane or water usage. This RV has a full body paint scheme and we will have an additional step in matching the replacement access panel to the outside when replacing this hated device.

  6. I’m glad you mentioned that tankless water heaters are much smaller and have less risk of spillage. My husband and I have been thinking about getting a new water heater, but we don’t have the room for a bigger one. I like how a tankless water heater would be smaller and could fit in the space we have. Thank you for the information!

  7. I agree with most of what you have said. Also, I’m glad you mentioned that tank-less water heaters are much smaller and have less risk of spillage. Great blog, thanks for sharing this!

  8. What kind of cost is there to purchase and change to this system we now have a 6 gal and it’s never enough

  9. I was wondering ( I live in a 5th wheel) if a portable hot water heater can be put in an RV to keep water hot for showers? Or what would be best and cheapest? I’m not goin to do it now but maybe in the future. Thanks

  10. I also live in my 5th wheel n my electric/propane water heater went out. This was two years ago. Purchased a Girrard tankless on demand water heater. Not only has this given me hot water in less than ten seconds but you can believe this or not.. l have a two hundred gal. portable hot tub n can fill it up without running out of hot water! I’m not kidding man!

  11. Since the cost of a whole house is very expensive I am put smaller ones on each area of water usage
    except the washer (Cold water) in the RV some with 4 g/m are 140 dollars and easy to connect if you are handy with tools

    1. Hi Len,

      Appreciate the comment. Could you elaborate as to why? What has your experience been like?


  12. Atwood tankless in my 2014 newmar needed a $5 reset switch. Atwood said no longer available, no longer made. 4 yr old water heater and cant get simple part. Atwoods answer to my problem , “buy a new water heater “.

  13. I wish the article would go further into the difference between propane, 110volt, 120volt, 208volt, and 240volt. I have a 30Amp 5th wheel and what I am finding out is 110v or 120volt is not enough to take a shower with, let alone rinsing soap out of my wife’s long hair. That is the problem I am having with my 6gal tank. I see people complaining about the time it takes to get hot water and how much water it uses. I have found Truma on demand hot water heater to be a hybrid with instant hot water, they also offer a combination hot water heater/furnace. I am still looking for a solution. If I go tankless, I will probably loose the ability to use shore power to heat my hot water. I’m thinking about getting a 120v and plumbing it into the inlet of the 6gal water heater & use it when I have shore power.

Leave a Reply

Your email address will not be published.