A home’s water heater is very important in providing comfort to the residents. Lack of a hot water supply is detrimental to cleaning and bathing. Before there were indoor plumbing tanks of water were brought into the house, heated in the fireplace and used as needed. Today, there are two basic types of water heaters: tank and tankless. The energy supply is natural gas, propane, oil and electric. Tank sizes run from 5 gallons used in public restrooms to 100 gallons for a private residence. Tankless system sizes are measured in their output BTUs.
What does a home inspector look when looking at a water heater? We determine the type and fuel supply. We determine its age and look at the overall condition of the unit. We comment on any corrosion on the unit. We look at the vent pipe if present. We look for proper slope, proper connection to other fossil-fuel-burning appliances, and comment on any corrosion.
Fossil fuel-powered units used to be lit by a fire source and a thermocouple. Today, gas and propane units are lit the same way gas and propane barbecue grills are lit. This is for the safety of the occupants. Oil-fired water heaters require an open fire source to light. Do not try to light any fossil fuel starter if you are uncomfortable. Electric water heaters are powered by a dedicated circuit breaker and one to two heat sources in the side of the tank. The thermostat cover is removed and the temperature is adjusted with a flat head screwdriver.
Fossil fuel-powered units last 10-15 years, electric units will last 15-20 years. The tankless units do not have enough data to make a life span prediction. The units will leak from the tank seams or around the valves and supply pipes. Virtually all leaks start very slowly, there are events where the leak overwhelmed the area it was stored in, but these are exceedingly rare. One returns from outside the house notice a small leak on the floor and it is draining to the low spot in the room. In Michigan, nearly all water heaters are located in the basement, where floor drains are required. Where water heaters are not located on the lowest level, the water heater should be equipped with an overflow pan that can drain into the plumbing drain system. If you have one of these make sure the input into the drain is not clogged. If your water heater is located in the utility closet without an overflow pan above the crawl space, I have seen severe water damage to the floor joists and subfloor caused by a leaking water heater that went unnoticed.
Water heater replacement is relatively easy, it is most impacted by its location in less than desirable locations. One calls a qualified plumbing contractor to replace a water heater. The plumber goes to the plumbing supply store and buys a water heater. The qualified plumbing contractor arrives at the house and will replace the water heater in about an hour. The makes water heaters off the shelf items. For older units we inform the buyers: “Budget for replacement” is the term we use for older systems. In Michigan, the worst place for a water heater is an unconditioned space such as a crawl space, or an uninsulated garage or closet. We highly recommend the relocation of these units into the conditioned space of the house.
There are two water supply pipes in the top of the water heater, a temperature/pressure relief (T/PR) valve located in the top or the top part of the side, and a drain valve located at the bottom of the side. If any of these valves leak it is a pipe or valve problem, not a water heater problem. A qualified plumbing contractor can repair or replace these items as needed.