Water heaters on the island lead a harder life than they would inland, and where yours sits matters as much as how old it is.
Salt air and exposed installations
Where a heater sits in an enclosure under an elevated house, salt air reaches the casing, the fittings and the flue. The tank may be sound while the connections around it corrode, so it is worth having someone look at the whole installation rather than only the unit.
Rentals fail at the worst moment
A heater that has been fine all winter with nobody using it will show its age the first week a full house is running showers back to back. If you let a property here, replacing a marginal heater in the off season costs far less than losing days of a booking and dealing with an unhappy review.
What is worth repairing
A thermostat, element, thermocouple or gas valve on a tank under about eight years old is normally worth fixing. If the tank itself is leaking rather than a fitting, it has rusted through and no repair will hold — we will tell you that plainly.
Worth doing in the off season
Flushing the tank, checking the anode rod and looking over the flue and fittings for corrosion. On the island the anode rod in particular is worth checking more often than the manual suggests.