Refurbished water heaters generally function well, but they also have a limited lifespan. While proper maintenance can keep a unit running longer, metal fatigue and corrosion might occur more quickly on a refurbished unit.
Most components on a water heater can be replaced, and experts know how to look for signs of strain when inspecting a unit. While there are no standards for refurbishing a unit, those selling used water heaters typically look for signs of metal fatigue and corrosion before restoring a unit. They also check safety values to make sure the water heater doesn't fail catastrophically.
Nevertheless, metal fatigue is often invisible, as water heaters undergo constant stress. Cold water enters the unit, causing the metal to contract. As the water heats up, the metal expands. Additionally, water heaters are often placed in garages, where they experience more temperature changes. Cracks too small to see in even a thorough inspection can form and spread over time.
Regardless of whether a water heater is new or used, regular inspections and maintenance is important. Water heaters often face corrosion when water collects at the bottom of the platform holding the take, so keeping the outside of the water heater dry can extend its life span. Regular review by an expert can help homeowners find signs of premature strain prior to a catastrophic failure.