Hello: the high recovery thermos tend to last less because the tank has up to 5 ventilation tubes that pass through many more solder points than a common thermos, you can buy the brand sherman are in price and rehem manufacturers are good for you last you have to change the magnecio anode once a year buy a thermo common, make sure that the water that feeds the thermos is from the tank because if it is running or pressurized water, it takes away life from the thermos greetings