Water heaters
Tank vs. Tankless Water Heaters
Updated · Written by the SteadWell team
Short answerTank heaters cost less to buy and install and need little maintenance. Tankless heaters provide continuous hot water and use less standby energy, but cost more upfront, may need gas line or venting upgrades, and need yearly descaling.
How they differ
A tank keeps a set volume of water hot all the time. A tankless unit heats water only when a tap opens. That's the source of every trade-off below.
Choose a tank if…
- Your budget is focused on upfront cost
- Your gas line is small or you're on electric with limited panel capacity
- You'd rather not schedule yearly maintenance
Choose tankless if…
- You run out of hot water with a tank
- You want to free up floor space
- You plan to stay in the home long enough for energy savings to add up
The installation questions that decide it
Gas tankless units often need a larger gas line than a tank, plus new venting. Electric tankless units can need a large electrical service. Those costs vary more than the unit price does, so get them assessed before you choose.
This guide is general information, not a substitute for an on-site assessment. Read our editorial standards.