Point-of-use tankless water heater guide

A point of use tankless water heater puts hot water right where you need it. Here’s when it makes sense and how to size it.

Updated November 5, 2026 · 3 min read · By Tankless Water Heater Shop Editorial Team · How we write guides

Key takeaways

Point-of-use heaters serve one fixture and eliminate the wait for hot water at far sinks.
120V units suit hand washing; 240V units are needed for kitchen sinks and showers.
A mini tank (2.5–7 gallons) is an alternative when you need full faucet flow briefly.

When point of use makes sense

A far bathroom or kitchen where you wait a minute or more for hot water.
Additions, garages, workshops and offices without hot water plumbing.
Wet bars, break rooms and hand sinks.
Tiny homes and studios where one or two fixtures are all you need.
Supplementing a main tank or tankless heater for one high-use fixture.

Sizing a point-of-use tankless water heater

Fixture	Flow	Warm climate (45°F rise)	Cold climate (75°F rise)
Hand washing (0.5 GPM aerator)	0.5 GPM	3.3 kW (120V possible)	5.5 kW (240V)
Bathroom faucet	1.0 GPM	6.6 kW	11 kW
Kitchen sink	1.5 GPM	9.9 kW	16.5 kW
Shower	2.0 GPM	13 kW	22 kW

Calculated as kW = GPM × temperature rise × 0.1465. Shower figures assume full hot flow; mixing with cold water lowers the real requirement somewhat.

120V vs 240V

A 120V circuit limits a heater to about 3.5 kW, enough for a hand-washing sink with a low-flow aerator. Anything bigger needs 240V and a dedicated double-pole breaker. See point-of-use water heaters for options.

Most point of use electric tankless water heater models, also called point of use water heaters electric, are 240V for this reason.

Tankless vs mini tank

	Point-of-use tankless	Mini tank (2.5–7 gal)
Hot water supply	Continuous, limited flow	Full flow until stored water runs out
Electrical	120V or 240V, higher amps	Often 120V plug-in
Size	Very compact	Larger, under-sink
Best for	Hand washing, steady use	Kitchen sinks, short bursts

Installation tips

Mount as close to the fixture as possible.
Check the minimum activation flow against your faucet aerator.
Use the breaker and wire size specified in the manual.
Install isolation valves where possible for maintenance.

Shop point-of-use heaters

Under-sink tankless and mini-tank heaters with voltage and amperage on every listing.

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Frequently asked questions

What is a point-of-use tankless water heater?

A small electric water heater installed at or near one fixture, such as under a sink or next to a shower, that heats water on demand. It delivers hot water within seconds because the pipe run is short.

Can a point-of-use water heater supply a shower?

Yes, if it is a 240V unit with enough power for your climate, typically 9–13 kW in warm areas and 13–18 kW in colder areas. A 120V unit is not powerful enough for a comfortable shower.

Is point of use better than a recirculation pump?

For one or two far fixtures, a point-of-use heater is often simpler and cheaper. For several far fixtures, a recirculation system on the main heater may be better.

ShopPoint-of-use and under-sink water heaters ShopElectric tankless water heaters GuideRecirculation pump guide GuideBosch tankless water heaters GuideStiebel Eltron Tempra and DHC

This guide is general information for U.S. homeowners, not professional advice. Gas, electrical and venting work must follow the manufacturer’s instructions and local codes, and in most areas requires a licensed plumber, electrician or gas fitter and a permit. Specifications and prices change; always confirm details on the product page and in the installation manual.