Bests & Worsts Reviews from Amazon

This review has no bearing on the seller but rather the unit itself and manufacturer's guidance prior to purchasing. I called Stiebel Eltron to find out what unit I should purchase given the amount of fixtures and flow rate of each in my house (1 shower head - 1.9 GPM, 3 sink faucets ranging from 1.2 to 1.5 GPM). I also explained that a future addition of a master bed/bath is potentially coming down the pipeline and that I would like to have the water heater be able to handle that load as well. The customer service rep I spoke to pointed to the Tempra/Plus Sizing Guide that shows my average tap water temperature (52* F) and that the Tempra 29 Plus will handle up to 3.7 GPM max flow rate. Or "you will be able to run two showers and a sink faucet all at the same time and not affect the temperature or flow rate." Which is fine for my needs. So I bought it. After running all the electrical needed to the unit (not a cheap endeavor) the unit was hooked up. Pros: I love the easy to use interface, the unit itself is tiny and extremely quiet when in use. Silent in fact. Cons: The Tempra 29 Plus is not a 3.7 gpm unit based on 52* F tap water. What is buried in their literature, that the customer service rep did not point out, is a graph that shows Flow Rate vs Temperature Rise. If I set the unit to 120* (normal temperature setting) that equates to a 68* F temperature rise. A 68* temperature rise, according to their graph, shows that the Tempra 29 will only handle approx 2.6 GPM flow rate. Which means I can only run one shower without affecting temperature or flow rate. Once a faucet is turned on, or any other fixture, the flow rate severely drops because the actual max flow rate is exceeded. So why the discrepancy between the sizing guide and the Temperature Rise vs Flow Rate graph? Makes no sense. It also makes no sense that this unit is literally only a one fixture unit being sold as a three fixture unit. Another thing to note is the temperature of the water, even if it's just one shower running, would fluctuate. The water temperature was not consistent throughout a shower period. I called and spoke to tech support several times throughout a two day period. They did not have any solutions for me. So I am currently in the process of returning the unit to Amazon. I will update this review to include how that went.