Tankless Hot Water Heaters

Instant On Demand Tankless Hot Water Heaters Are Here To Stay!

Rheem Electric Water Heater Tankless vs 50 Gallon

Rheem Electric Water Heater Tankless vs 50 Gallon

It seems, we as humans want everything now and on demand.  This includes wanting hot water in our homes fast. With people wanting their hot water in an instant we are seeing the popularity of the  new instant tankless hot water heaters growing as Homeowners are realizing the benefits and the great features which are giving a boost to its much gaining popularity.

In this post you will find out about the features and what you should know when considering this option. This post focuses on comparing the tankless electric water heater to the standard tank type water heater we are all familiar with.

Quick View – Rheem Tankless RTE-18 vs. 50 Gallon Water Heater

Some BIG Differences for Consideration

Just by looking at the image above, the huge size difference is obvious between the two heating units.  The heater on the left is a Rheem Tankless Water Heater RTE 18 and the second is a Rheem 50 Gallon Hot Water Heater.  This image is an actual representation of the size difference of the two units.

Quick Reference –
Features of Tankless vs. 50 gallon Tank Water Heater

Hot Water Heaters Charts

Hot Water Heaters Charts

As you can see there are some great differences between the two water heater units. Below are some additional points to consider..

NEVER Run Out Of  Hot Water @ 5 GPM

Tankless Instant Hot Water Heater Texas Home Exteriors

Tankless Instant Hot Water Heater Texas Home Exteriors

With the Rheem RTE 18 Tankless Hot Water Heater, you will NEVER run out of hot water. This is because the water is heated on demand. If you so desired, you could take a shower for a month and never run out of hot water. A typical shower will use about 2 GPM. This is why when you take a long shower with a typical tanked water heater, the water goes cold and the 30 40 or 50 gallon unit can not keep up.

When this happens, their is a wait for that 30, 40 or 50 gallons of water heat up again, how long depends on the tank size of your heater and the temperature you like the water. Keep in mind that the usage flow rate for a tanked water heater is only about .75 GPM, this is why it will never catch up with the 2 GPM flow rate shower or bath you are trying to enjoy.

Installation Cost – One Person Installation vs. Two

Although the tankless water heater option may cost a small amount of more money up front, the installation cost should cost you less for a few reasons. First of all, you do not need a water heater drain pan/leak catcher underneath as the traditional tanked unit to catch overflow from the pop off valve (not to mention events like a leak from the rusted out bottom happen, then a pan is a must with this option). And, it is quite easy for one person to install the tankless water heater vs. the required two people needed for the tanked water heaters, should lower the cost of installation.

Electric Usage Tankless vs. A Standard Tanked

Is energy efficiency important to you? Well then here is something to think about, a tankless water heater only uses electricity when being used, on demand. The tankless unit will use about twice the electric draw @ 35 amp (approx) over a tank unit but the running time is less than 1/10 of the time. Most standard 30, 40 and 50 + gallon water heaters run in long cycles on and off 24/7/365 days a year. But keep in mind that this draw on costly electric is slow @ 15 amp (approx) but it is all day long 7/365. The tankless instant hot water heater uses twice the electric, however runs approximately 1/10 of the time rewarding you with 35-65% on average saving in electric usage. 

No Hot Water Relief Valve Needed

Traditional tank water heaters fill up then begin heating process. During this process and the heating of so many gallons water at a time, the water expands as it heats requiring there be a hot water pressure relief valve in necessary. The hot water pressure relief valve is designed to allow the water to escape so the tank does not have to endure too much pressure or even possibly explode which could be dangerous and could flood your home with how water. A tankless water heater needs no tank and therefore does not require the installation of an expansion valve.

Size of Heating Unit

This is where the tankless water heating unit wins over big time and one of the most obvious reasons. The units are significantly smaller than the tank water heaters and there is even make a version that is about half the size represented here for compact space like placement under sinks or in a motor home, etc. Try putting a traditional tank water heater under most sinks.

The Down Side to Tankless

Most homeowners love the ease and performance of their tankless water heater. However there is one drawback we have found.  Because the unit draws more current in short intervals of usages, as opposed to a slow 24/7365 usage pattern, you can see the effects of with your home lights flashing during the strong current draw. This is very slightly noticeable but it is something the public should be aware of, please respond if you have a remedy for this issue.

Quick Bullet Points To Consider Benefits of Tankless Water Heaters

  • Simple & Fast Installation
  • Space Saving
  • Much Less Energy Usage
  • Longer Warranty (no possible leaking tank)
  • No Drain Pan Needed
  • No Extra Initial Cost
  • Increased Dependability


So in a nutshell, the tankless instant hot water heaters are  a great option for heating water and they are here to stay. They provide all the hot water one could desire in a easy-to-install compact unit that takes up much less space. The unit can be easily installed by one person and the energy efficiency of the unit will save homeowners money. In this day and age, this is a very good thing to have if you are a homeowner and want lower utility bills. Note: a licensed electrician and plumber is needed for installation. 

Questions or Comments?

Here at Texas Home Exteriors, we encourage you to ask any questions, share your thoughts and comments below on the tankless water heaters. Thank you most kindly. Texas Home Exteriors INC.

This entry was posted in Energy Efficiency, Inside Your Home, Texas Home Exteriors. Bookmark the permalink.

11 Responses to Tankless Hot Water Heaters

  1. Michelle says:

    This is a great article thank you for posting. A tankless instant water heater is something that my husband and I are considering. I will show him this as soon as he gets home thanks again! Michelle

    • Greg Kapitan says:


      Thank you for comments about our Texas Home Exteriors blog post on Tankless Hot Water Heaters. We are glad that you have enjoyed it and are considering this smart energy saving option for your home. Greg Kapitan

  2. Ann says:

    Wow! I had no idea that this would be such a great product at such a minimum price difference. We have a family of four with a 50 gallon hot water tank and there is always a wait for hot water especially during the winter months. Thanks for this great information. Very well written article.

  3. Kimberly Kovatch says:

    Excellent tankless water heater article that you have made here. I certainly appreciate this site. Continue the good work TX Home Exteriors!

    • Greg Kapitan says:


      Thanks so much! As you can imagine, there are so many homeowners that have no idea that the tankless water heaters even exist. Yes, you will save money big time with the installation of one when the time for replacement comes. Thanks again!! Greg Kapitan of Texas Home Exteriors.

  4. Hugh Markuson says:

    Appreciating the persistence you put into your blog as this is good information.

  5. Gary Ware says:

    “Because the unit draws more current in short intervals of usages, as opposed to a slow 24/7365 usage pattern, you can see the effects of with your home lights flashing during the strong current draw. This is very slightly noticeable but it is something the public should be aware of, please respond if you have a remedy for this issue.” 1. Use NG instead of Electric, 2. Increase gauge of wire to panel and to tank. Excellent comparisons.

    • Greg Kapitan says:


      Wow, it sounds like you know what you are talking about. Thank you for this good advice. That makes total sense to increase that weir dimaniter to the panel and tankless unit. Thanks for your compliment about our blog. Greg

  6. Valerie says:

    One other thing I think this article failed to mention is that when your power goes out, especially for an extended period of time, you have no hot water! We had a tankless, a hurricane knocked out the power for a while and we had to take some cold showers!

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