A point-of-use heater sits at one fixture. Mini tanks of a few gallons store hot water and plug into 120 volts in most models; small tankless units of 3 to 8 kW heat on demand at hand-washing flows. They fix a long wait at a far sink, serve an addition or a garage, or take a load off the main heater.
Mini tank or tankless?
| Mini tank | Small tankless | |
|---|---|---|
| Delivers | Stored gallons at full flow, then recovers | Endless, at a flow its power can lift |
| Power | Usually 120 V | 3.5 kW and under on 120 V; larger on 240 V |
| Best at | Short draws at a sink | One low-flow fixture |
What a small tankless can lift
A 3.5 kW unit lifts 0.5 GPM by about 48°F, fine for a 0.5 GPM bathroom faucet; WaterSense bathroom faucets run 1.5 GPM or less, and the federal maximum is 2.2 GPM, at which the same unit lifts only about 11°F.
Examples
Mini tanks: VEVOR FJI-POR-70S2 18-Gallon Mini-Tank Water Heater, VEVOR FJI-POR-50S2 12-Gallon Mini-Tank Water Heater and GEESEN GX10 Mini-Tank Water Heater. Small tankless: Bosch 7738007417 8.5 kW Point-of-Use Tankless Water Heater, Titan N85 8.5 kW Point-of-Use Tankless Water Heater and EcoSmart ECO 8 Point-of-Use Tankless Water Heater.
