Rheem Performance Review


Rheem’s Performance model is a great value for those who have an indoor electric-only setup in their home. The Rheem Performance model is a beautiful and slim design that’s simple to install, requires no venting, and has a digital temperature display that you can configure to your liking.

The temperature range is 80 – 140°F, and is 99.8% energy efficient according to the manufacturer. There are 3 heating elements which are copper for better durability and easy replacement. If you’re unsure what model you’re looking for still, we have a buyers guide write up here on our site www.iwaefficient.com.


  • Digital temperature control in 1°F increments
  • Maximum 6.6 GPM, average 5.3 GPM
  • Temperature range 80 – 140 °F
  • Self-modulation technology for advanced efficiency
  • 0.3 GPM activation flow
  • 3 / 4 inch fittings
  • Flex hose compatible
  • 27 kw, 112 amps that requires 3 x 40 breakers, 240 volts, 8 AWG


The Rheem Performance model comes with a 5 year limited warranty on the heater elements and a 1 year warranty on parts.

Advantages & Disadvantages


  • Inexpensive
  • Great for small to medium size homes with low demand
  • Self-modulation technology
  • 5 year limited warranty
  • No ventilation required
  • Easy to replace heater elements


  • Requires frequent maintenance & cleaning from scale and sediment build-up
  • Heater elements may need to be replaced
  • Requires dedicated wiring and breakers


The Rheem Performance is a great choice for those looking for a strong electric tankless unit with small to average sized homes. It is simple and straightforward to use, with impressive energy efficiency to boot. Its self-modulation technology is a no brainer that gives it an edge over other electric type tankless heaters, while remaining inexpensive to buy.

If you need something a little more conventional, doesn’t need ventilation and is easy to maintain the Rheem Performance is definitely worth considering and a great value for the money.

What people have to say

“I wanted this unit in particular because it has a really slim design that would be perfect for my detached garage. Please keep in mind it needs dedicated 3×40 amp breakers but besides that it’s great.”
“This is a replacement for an old electric tankless heater I had bought 7 years ago. I’m happy to see the price in general for tankless units has come down. Love the digital temp control and display, and the threaded heating elements.”
“Very pretty and slim design, saves a lot of space and uses less energy than a regular water heater.”
“Got this when my old heater was rusted out and started leaking. Had this for a couple weeks now and I’m very happy with the money spent, besides needing an electrician to come set up and get it wired, well worth the money.”
“Although I had to upgrade my breakers when having that professionally wired, it’s well worth the money in savings and I look forward to it paying for itself. Not ever going back to typically tank heaters!”
“Perfect for our big family who needs to shower back to back in the morning or evening, no wait time anymore!”
“Great that it only uses energy when needed, rather than a tank keeping the water hot 24/7 so i’m looking forward to seeing the change on my electric bill that’s coming up”
“Happy with performance, recommended it to my parents and friends.”
“Excited to have this installed finally, i only recommend you have a licensed electrician to do the work to make sure it’s wired and everything is done properly.”