Rheem is one of the largest and most respected brands for tankless, on-demand hot water heaters. Water heaters should last between 8 and 12 years, and they're a pretty expensive purchase when the time comes to replace one.
Why is my tankless water heater not getting hot enough?
Because tankless units only heat water as it's needed, running too many hot water appliances at the same time could mean the unit just can't keep up. ... On the other hand, your “no hot water” problem could be cause by a bigger issue such as: Plugged heat exchanger (due to hard water) A blocked vent/air intake.May 8, 2018
What size tankless water heater do I need for a family of 4?
Number Of Family Members: Gas Tankless Heater Size (GPM) Electric Tankless Heater Size (kW)
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What size tankless water heater do I need for a family of 3? 7-9 GPM 15-23 kW
What size tankless water heater do I need for a family of 4? 8-10 GPM 20-28 kW