Tankless vs. Tank Water Heater
A tank water heater costs less to buy and install and is simple to replace. A tankless water heater costs more upfront but lasts longer, saves space, uses less energy on standby and never runs out of hot water, though it limits how many fixtures can run at once.
Last reviewed September 2026
Tankless vs. Tank: side by side
| Factor | Tankless | Tank |
|---|---|---|
| Installed cost | About $1,500–$5,000 | About $900–$2,000 |
| Lifespan | About 15–20 years | About 8–12 years |
| Hot water supply | Endless, limited by flow rate | Limited to tank size |
| Energy use | No standby heat loss | Keeps a tank hot all day |
| Space | Wall-mounted, compact | Large floor footprint |
| Maintenance | Yearly descaling | Yearly flushing, anode checks |
| Installation | May need new venting, gas line or electrical upgrade | Usually a like-for-like swap |
Which one should you choose?
Choose tankless if
- You plan to stay 10 or more years
- You often run out of hot water
- You want to free up floor space
- Your gas line or electrical panel can support it
Choose tank if
- You want the lowest upfront cost
- You need a quick replacement today
- Several showers and appliances run at once
- Your home would need big gas or electrical upgrades for tankless
Cost comparison
| Option | Typical cost |
|---|---|
| Tank water heater, installed | $900–$2,000 |
| Electric tankless, installed | $1,500–$3,500 |
| Gas tankless, installed | $2,500–$5,000 |
| Hybrid heat pump water heater, installed | $2,500–$4,500 |
Ranges are typical US prices compiled by FixHomeCost. Prices vary by region, home and contractor, so compare 2–3 local quotes.
Common questions
Is tankless worth it over a tank?
Often yes if you stay long enough to benefit from its longer life and lower standby losses. If you may move soon, a new tank is usually more cost-effective.
Why does my tankless heater go cold sometimes?
The flow may be too low to trigger it, scale may be interfering, or too many fixtures are running at once for its capacity.
Which lasts longer, tank or tankless?
Tankless units typically last about 15 to 20 years, compared with about 8 to 12 for tank heaters.
Do tankless water heaters save money?
They avoid standby heat loss, which saves energy, but the higher installation cost can take many years to recover.