Water heaters will have specs related to efficiency and recovery rates. Find one that meets your recovery rate needs and then make you decision based on cost vs. efficiency and warranty. I am convinced the only difference between a 5 year warranty and a 15 year warranty is the warranty... Unless you are going to an instantaneous heater or high efficiency you will find little difference if any in quality.
For what it’s worth I usually go for the least expensive with a 10 year warranty.
Rege
For what it’s worth I usually go for the least expensive with a 10 year warranty.
Rege