How they differ
Storage heaters hold a fixed amount at temperature. When it is used up, you wait for recovery. On-demand units warm water only while it moves, so supply is continuous but limited by flow rate.
Considerations
- Simultaneous use of several showers and appliances
- Gas line size and venting route
- Water hardness and maintenance
- Space available
- Upfront and long-term costs
Installation
Tankless units often need larger gas lines and new venting. Tank heaters may reuse existing venting. Both need proper relief valves and connections.
Hard water shortens tankless life without regular descaling.
Help
See tankless service and tank replacement.
Space and venting
Tankless units mount on a wall and free floor space, useful in tight utility rooms. They need venting through an exterior wall within certain distances and clearances from windows and doors. Tank heaters take more floor space but may use existing vents.
Habits matter
Households that run several showers at once need a tankless unit sized for that flow, or they may see temperature drops. Very low-flow uses, like a trickle at a sink, may not trigger some tankless units. Tank heaters handle these situations simply but run out after heavy use.
Maintenance
Tankless heaters need descaling. Tank heaters benefit from flushing and anode checks. Both need venting checks on gas units.
When to put the tools down
Some of this is homeowner work and some is not. Stop and phone us if you see any of these:
- Showers going cold sooner than last winter
- Crackle and knock from sediment as it heats
- Brown tint on the hot side alone
- A puddle forming beneath the tank
- Anything involving the gas line, the venting or cutting into a wall
Quick answers
Will tankless cut my bills?
Standby losses drop, but savings depend on use, installation cost and maintenance.