Water Heaters

[jitagon]

I had to install three separate water heaters in my house, owing to the builder one but last not having the forethought to install copper piping for a central water heater. After just a year all three of them have died. I have been told by one of the numerous plumbers/electricians it's because the water pressure isn't strong enough. I have a two-way water pump which takes the water from the well up to a tank, which then releases it into the house.

Is it the pressure, or is it that the heaters are rubbish? Yesterday I went to a couple of shops to source new heaters and was told that Panasonic was the best but that the unit itself was only guaranteed for one year, while the heater was guaranteed for five(!?). Bearing in mind that most water heaters here (indeed, almost anything here) has at most, a guarantee of one year if you're lucky, is it the quality of the product?