xwdzswgs Tankless Water Heater Electric 110V, 3000W Instant Electric Water Heater, Under Sink Water Heater with Digital Display, On Demand Hot Water heater Electric for Kitchen Bathroom Washin

A small box under my kitchen sink changed the way I get hot water—within its limits. This 110V, 3000W under‑sink tankless unit is designed to serve a single fixture, and after living with it for a few weeks, I have a good sense of where it shines and where it falls short.

What it is and what it isn’t

This is a compact, point‑of‑use electric heater intended to eliminate the wait for warm water at a sink far from a main water heater. It has a simple digital display, a basic thermostat, 1/2‑inch NPT connections, and multiple safety protections (water/electric isolation, overheat shutoff, dry‑fire protection, and IPX4 splash resistance). It’s vertical‑mount only, and it doesn’t have a pump; it relies entirely on your home’s water pressure.

Importantly, 3000W at 110–120V is not enough power to supply a typical shower or fill a bathtub with genuinely hot water at normal flow. Expect it to support handwashing, light dish duty, or a utility sink—especially in small apartments, RVs, shops, or outbuildings—provided you manage the flow rate.

Installation experience

• Orientation: The heater must be installed vertically. Mounting horizontally triggered an E2 fault during my testing. Once oriented correctly and fully purged of air, the error cleared.
• Plumbing: The unit uses standard 1/2‑inch NPT fittings. I used Teflon tape and braided stainless supply lines. Before power‑up, I opened the faucet to purge air and checked for leaks.
• Electrical: At 3000W, current draw is roughly 25–27A at 120V. That puts it beyond a shared 15A or 20A circuit. I treated it like a small appliance water heater and had it on a dedicated 30A breaker with appropriately sized conductors and a GFCI device, per local code. If you’re not sure about wiring and breaker sizing, involve an electrician. Do not share this with a garbage disposal, dishwasher, or anything else on the same circuit.
• Space and mounting: The housing is slim and light. It tucks neatly on the back wall of the sink base and leaves room for a trap, a filter, or a small RO tank if you have one.

Overall, installation is straightforward for a competent DIYer, but the electrical requirement is the gating factor. Treat it seriously.

Controls and interface

The front display is bright and easy to read. A long press toggles Fahrenheit/Celsius. You set a target temperature, but like all low‑power tankless units, the setpoint is a request, not a guarantee. The heater will do what it can given incoming water temperature and flow rate. There’s no advanced scheduling or mobile app, which is fine for a point‑of‑use device.

In use, I heard a faint relay click on start and stop, but otherwise it’s nearly silent.

Performance and flow management

Water heating math sets expectations here. With 3000W:

• At about 0.5 GPM, I measured a temperature rise in the neighborhood of 35–40°F.
• At about 0.3 GPM, the rise climbed to roughly 60–70°F.

Incoming water temperature matters a lot. With 55°F inlet water, I could comfortably wash hands at normal aerated flow (about 0.5 GPM) and rinse dishes at a slightly reduced flow. At lower inlet temperatures (winter in a cold climate), I had to use the faucet’s built‑in flow restrictor or partially close the supply stop to keep the outlet hot. With warm‑season inlet temperatures (65–70°F), the output felt properly hot even at moderate flow.

Key takeaway: the hotter you want the water, the more you need to limit flow. This is normal for a low‑wattage tankless heater. If you expect “scalding hot at any flow,” this is not the product for that job.

I did not attempt to run a shower with it; even with a low‑flow head, the result would be tepid in most homes. For a shower, look at 240V units in the 8–12kW range.

Everyday use

• Handwashing: Excellent. Instant warmth at the tap without waiting for the main water heater to send hot through a long run.
• Light dish duty: Good with a low‑flow spray or aerator. Removing flow restrictors to get a fat stream will cool the output.
• Utility sink or garage: Works well for quick rinse tasks.
• Bathroom vanity: Ideal, especially if the bathroom is far from the main heater.

The benefit I appreciated most was water savings. Not having to run a faucet for 30–60 seconds waiting for hot water felt great. For modest use, the energy draw is short and efficient.

Safety and reliability observations

• IPX4 is appropriate for under‑sink splashes, but I would still keep the unit high and away from the base floor.
• Dry‑fire protection worked; on an air‑locked first start, the unit faulted rather than overheat. Purging air fixed it.
• Heat at the cord and plug is a concern if someone tries to run this from a standard shared receptacle. On a dedicated, properly sized circuit, the housing stayed cool and operation was stable.
• The inlet screen is small and can clog in older plumbing. It’s worth installing a small inline mesh screen upstream if you have sediment.

Build quality

The enclosure is ABS with a clean, smooth finish; brass fittings are solid. The mounting points are reinforced. The display lens doesn’t scratch easily, and the buttons have positive feedback. It looks better than the price would suggest and doesn’t rattle or buzz.

Where it fits best

• A sink that’s a long way from your main water heater
• A workshop or garden sink where you occasionally need warm water
• An RV or small apartment with limited electrical capacity but a dedicated 120V circuit available
• Retrofit situations where adding a recirculation loop isn’t practical

Where it doesn’t fit

• Showers, bathtubs, or multi‑fixture loads
• Very cold‑inlet regions without flow management
• Installations lacking a dedicated 25–30A, 120V circuit

If you need higher output at typical sink flows without throttling, a 240V, 6–8kW unit is a better point‑of‑use choice. If you want whole‑home performance or a shower, plan on 12–18kW (or more) at 240V and appropriate wiring.

Tips to get the best results

• Mount vertically. Horizontal installation will cause faults and heating element issues.
• Purge air before energizing. Open the faucet fully and run water until flow is smooth.
• Use 1/2‑inch flexible connectors and Teflon tape; avoid overtightening.
• Add a low‑flow aerator (1.0–1.2 GPM) to your faucet; it improves perceived heat.
• Dedicate a properly sized circuit with GFCI protection. Don’t use extension cords.
• Expect the thermostat to be a limiter, not a promise. Adjust flow to control temperature.

Value

As a targeted fix for a single sink, the value is strong. It costs far less than adding a recirculation loop, and it avoids the standby losses of a small tank heater. For households that use a distant sink frequently for short tasks, the water and time savings are real.

Recommendation

I recommend this under‑sink tankless heater for point‑of‑use applications where you can provide a dedicated 120V/30A circuit and you understand the flow‑versus‑temperature tradeoff. It delivers quick, consistent warm‑to‑hot water for a single sink, it’s compact and quiet, and its safety features and simple controls are well suited to daily use. I would not recommend it for showers, tubs, or anyone expecting “whole‑house” performance, and I’d avoid it if you can’t meet the electrical requirements. Installed correctly and used within its design envelope, it’s a practical, efficient upgrade that does exactly what it promises for the right use case.