Tank or tankless?
| Type | How it works | Things to ask about |
|---|---|---|
| Tank (storage) | Heats and stores water in an insulated tank, ready to use. | Size for your household, venting for gas models, space and drain pan. |
| Tankless (on-demand) | Heats water as it flows through, with no storage tank. | Flow rate for your peak use, gas line or electrical capacity, venting and descaling. |
| Heat pump | Moves heat from the surrounding air into the water. | Space and ventilation around the unit, and any local rebates. |
Safe checks before you call
- Electric: check the breaker hasn't tripped.
- Gas: check the pilot light or ignition status as the manual describes, and that the gas supply is on.
- Check the thermostat setting.
- Look for water around the base. A leaking tank usually needs replacing, so turn off the water supply to it and the power or gas.
Never block or tamper with the temperature and pressure (T&P) relief valve. If you smell gas, leave the building and call 911 or your gas utility from outside.
Permits and licensing
Many cities and counties need a permit to replace a water heater, so it can be inspected for safe venting, gas connections, relief valve piping and, in some areas, seismic strapping. A licensed plumber usually pulls the permit. Ask whether it's included in the quote.
Comparing quotes
- Is the price for the unit, labor, permit, haul-away of the old heater and any code upgrades?
- What warranty comes with the tank or heat exchanger, and with labor?
- Is the unit sized for your household's hot water use?
- Are there utility or government rebates for high-efficiency models? Check your utility and ENERGY STAR.
Last updated: 14 October 2026
