Questions people ask
What size water heater do I need?
Size a tank by its first hour rating, not just its gallons. Add up the hot water your home uses in its busiest hour (about 20 gallons per shower in the Department of Energy worksheet), then pick a heater whose first hour rating at least matches that total. The DOE example of three showers, a shave and some hand dishwashing comes to 66 gallons.
How long does a tank water heater last?
Fixr puts tank water heaters at 8 to 12 years. Hard water, a spent anode rod and skipped flushing shorten that; regular anode checks and flushing help a tank reach the top of the range.
How much does it cost to replace a water heater?
Fixr’s 2026 installed ranges are $700 to $2,700 for a gas tank, $500 to $3,500 for an electric tank, and $1,200 to $4,600 for a heat pump (hybrid) model. Venting, gas line, electrical and code upgrades push a job toward the top.
Do I need an expansion tank?
You need some form of thermal expansion control when the water system is closed, which happens when a check valve, backflow preventer or pressure reducing valve stops heated water from pushing back into the street main. Many jurisdictions apply this when a water heater is replaced. A small potable expansion tank on the cold line is the usual fix.
How often should I flush a water heater?
Rheem recommends flushing once a year, and every six months where the water is hard. Flushing drains the sediment that settles on the bottom of the tank.
Sources: DOE Energy Saver, Fixr, Rheem, NC Office of State Fire Marshal. We have not tested these products; see how we choose.