Glass-lined tanks are insulated steel cylinders with an enamel coating on the inside – the lining helps prevent corrosion. If it’s not installed properly, the water heater can explode. There are standards that regulate the safety of installation and design of water heaters. Certification marks on them from approved agencies indicate compliance with approved standards.
Conventional residential water heaters have life expectancies that vary, typically having a lifespan of roughly 10 years based on the following factors: usage volume, correct installation, maintenance, and construction quality.
A water heater should normally be installed upright. Installing a water heater on its side will place stress on it due to inadequate support for the pipes and heater as a whole, and may cause a shorter lifespan. Water heaters should be installed in well-ventilated areas, not just for fire safety and nitrous-oxide buildup, but because poor ventilation can also shorten its lifespan. It should also not be placed in an area susceptible to flood damage, as water can rust out the pipes and exterior. A water heater is best placed in an easily accessible area for maintenance, and should also be readily visible for fire and health-hazard requirements.
The life expectancy of the water heater depends on the volume of water used. If large quantities of water are being used, the water heater will have to work harder to heat it. The greater the volume of water, the greater the abrasive effect of the water will be on the pipes, tank materials, etc.
Cheaper water heater models will have a shorter lifespan, while more expensive models will generally last longer. Check the warranty as a good indication of a water heater’s construction quality, as longer warranties naturally imply sound construction. According to a 2007 Consumer Report that deconstructed 18 different models of water heaters, models with longer warranties were of superior manufacturing quality, with 9- and 12-year models usually having larger or higher-wattage heating elements, as well as thicker insulation. Models with larger heating elements have a much better resistance to mineral buildup or scum.
Porcelain casing provides an additional layer of protection against rusting and a greater level of heat insulation. Some models come with a self-cleaning feature that can flush the pipes of mineral deposit buildup, which can affect the unit’s lifespan. Models with larger or thicker anodes are better-equipped to fight corrosion.
Maintenance & Parts Replacement
If you have hard water, that is another consideration when looking at estimating the lifespan of a water heater. If you live in an area where there’s a higher mineral content to the water, water heaters have shorter a lifespan, since mineral buildup reduces its efficiency. Even with soft water, some mineral deposition is still a possibility. To counteract mineral buildup, periodically flush the water heater system. This process also heats the water in the tank. Pricier models typically come equipped with a self-flushing feature. While manual flushing is required in some models, it’s important to not damage the water heater valve, which is easy to break due to it being made of plastic.
Although an older model may appear to be well-maintained, is the maintenance worth it? Warranties often do not include labor costs, so if the total repair cost per year is greater than 10% of the cost of buying and installing a new water heater, it’s not worth replacing any parts that have been damaged.