Water Heaters: Repair, Replacement & Buying Guide
A water heater is usually either a storage tank that keeps hot water ready, or a tankless unit that heats water as it flows. When one acts up, start with the symptom below: many problems are a single part, and you only need a new heater when the tank itself leaks or the repair costs more than the heater is worth.
Water heating is about 18% of a typical home's energy use, per the Department of Energy, so the type you replace it with matters for years.
Start with the problem
- No hot water at all. Start with no hot water, or go straight to electric heater, no hot water or pilot lit but no hot water.
- Not enough hot water. See not hot enough and runs out of hot water.
- Leaks. Leaking water heater covers where it's coming from, with separate pages for leaks from the bottom, leaks from the top and a leaking relief valve.
- Noises, smells and color. Popping and rumbling, rotten egg smell, rusty hot water.
- Gas pilot problems. Pilot light basics, won't stay lit, and the thermocouple.
- Tankless error codes. Rinnai error codes.
Repair, parts and upkeep
Most repairs are one part. Read water heater repair first, then the part: elements and thermostats, anode rod, relief valve or expansion tank.
HomeGuide puts a typical tank repair at $150 to $700, and suggests replacing instead when the heater is over 10 years old or the repair tops half the price of a new one. Routine maintenance, mainly a flush and an anode check, is what stretches the lifespan.
Replacing or buying
A standard tank costs $600 to $3,100 installed, a tankless unit $1,400 to $5,600, and a hybrid heat pump $2,000 to $4,600, per HomeGuide. Start with water heater cost and replacement cost, then pick a type:
- Gas vs electric
- Tankless vs tank
- Heat pump water heaters and their installation cost
- Tankless installation cost
- Point-of-use heaters
Size it before you buy with the sizing guide. Buying at a big-box store? See Home Depot vs Lowe's installation cost. The installation guide covers what the job involves.
FAQ
What is a water heater?
It's the appliance that heats and supplies your home's hot water. Storage models keep a tank of water hot. Tankless models heat water only when a tap opens, and heat pump models pull heat from the surrounding air into a tank.
Where should I buy a water heater?
Plumbing supply houses, big-box stores and plumbers all sell them, and HomeGuide notes that Lowe's and Home Depot arrange installation through licensed plumbers. The installed price matters more than the shelf price, so compare full quotes.
What is the best type of water heater?
For most homes replacing a tank, a like-for-like tank is the cheapest to install. A heat pump model costs more up front and less to run, and tankless suits homes with the gas supply and venting to support it. Match the choice to your fuel, space and budget.
Can a hot water tank freeze?
Yes, in an unheated garage, crawlspace or a vacant house in winter. If power or gas is off during a freeze, drain the tank to protect it. Insulate exposed pipes as well.
All guides in this section
Fix it
How-to
Cost
Buy
Learn
Look up an error code
Sources
- HomeGuideWater Heater Installation Cost (opens in a new tab)
- HomeGuideWater Heater Repair Cost (opens in a new tab)
- U.S. Department of EnergyWater Heating (opens in a new tab)