Xiaomi launches a new smart, silent and compact water heater: instant hot water

Harriet Pemberton • April 28, 2026 03:52

Homes keep getting smaller, mornings feel noisier, and everyone’s patience is under pressure.

A new under-sink device is designed to take the stress out of the scramble at the tap by combining quiet operation, precise temperatures, and phone-first control. Xiaomi is aiming at the awkward “dead time” between turning the tap and getting properly warm water, with a compact point-of-use water heater made for modern flats and busy household routines.

Xiaomi point‑of‑use water heater: the essentials

The idea is straightforward: fit the unit near a tap or shower, connect it to Wi‑Fi, choose an exact temperature in the Mi Home app, and get hot water without the usual wait. It’s built to be compact enough for a narrow wall or the cupboard beneath a sink. Sound levels are intended to stay low-closer to a quiet library than a clattering boiler-and the temperature is meant to hold steady rather than surging and dipping with small changes in flow.

Instant heat at the point of use shortens long pipe runs, reduces waste, and keeps the temperature where you set it.

What changes in day‑to‑day life

In many homes, water is wasted while the hot line warms through. Independent estimates commonly put that waste at 6–10 litres each time you run a tap waiting for heat. By producing heat right beside the outlet, this Xiaomi unit reduces those “dead legs” in the plumbing-so you spend less time waiting and send less lukewarm water down the drain.

It can also make routines feel calmer and more predictable. Instead of guessing at the mixer, you can rely on presets such as 37–38°C for a shower, 40–45°C for greasy pans, and around 35°C for children’s handwashing. The app supports profiles and scenes, so you can build a gentler night mode, add a guest safety limit, or set a geofenced “nearly home” warm-up (where your wider setup supports it).

Quiet hardware matters. When the heater fades into the background, kitchens and bathrooms feel less hectic, even when the household isn’t.

A UK practical note (electrics and compliance)

Because this is an electric water heater installed in a wet area (often under a sink), UK homes typically need careful attention to electrical protection and routing. Depending on your property and where it’s fitted, you may need an appropriately rated circuit, RCD protection, and installation that aligns with UK requirements (often handled under Part P by a qualified electrician). If you rent, get permission before any plumbing or wiring is altered.

How it works (and why it can feel quicker)

This is an electronic, on-demand heater designed for short pipe runs. Flow sensors and temperature probes work together to maintain your chosen set-point via rapid micro-adjustments. With less distance for water to travel, the system can avoid some of the temperature swings that are common with long pipe runs or large storage tanks. And because there’s less pipework to warm up, you get fewer cold starts and fewer minutes with the tap running.

Noise reduction is a clear priority. Xiaomi positions the unit around “home library” sound levels, replacing the typical hums and knocks with a soft, consistent whisper. That matters in smaller flats, where bathrooms may sit near bedrooms and open-plan kitchens often double as working space.

Placement, setup and everyday control

Where you put it is the most important decision: install the unit as close as possible to the outlet you use most. Shorter pipework, fewer tight bends, and well-made connections all improve comfort and efficiency. After that, pair it over Wi‑Fi, open the Mi Home app, and build your presets plus any safety limits.

Suggested temperature presets

Shower comfort: 37–39°C for most adults.
Kitchen sink: 40–45°C to cut through grease without unnecessary waste.
Hands and children: 34–36°C with an anti-scald cap enabled.
Night scene: lower maximum temperatures after a set time to rein in energy use.
Filter reminder: plan checks based on local water hardness.

Use case	Suggested preset	Why it helps
Quick rinse	35–36°C	Uses less energy and reduces scald risk for short bursts
Daily shower	37–39°C	Comfortable range with less fiddling at the valve
Greasy dishes	42–45°C	Helps cleaning and can shorten the job

Common mistakes to avoid

Installing it too far from the outlet. Distance undermines the whole point-of-use advantage.
Setting 50°C “just in case”. Higher targets can increase bills and raise scald risk.
Forgetting about limescale. Hard water can clog filters and blunt performance quickly.
Skipping leak checks after week one. Fittings can settle after repeated heat cycles.

Energy, water and noise: what you can realistically expect

On-demand electric heaters only draw power when water is actually flowing. That means short, sharp bursts rather than the steady background consumption of a storage tank keeping water hot all day. In practice, the biggest savings often come from less time running the tap and tighter temperature control, rather than anything miraculous. If you’re replacing a long, centralised hot-water route with a local unit, the wait should shrink and the morning queue at the bathroom should ease.

Quieter starts can change behaviour too. If the unit is near-silent, you’re less likely to delay running water because someone is asleep in the next room. In compact homes, that’s a genuine quality-of-life improvement rather than just a spec-sheet detail.

Less waiting, fewer litres wasted, and steadier temperature can add up to lower stress and a lighter bill at the end of the month.

Compatibility and smart controls

The heater works with Xiaomi’s Mi Home app and supports leading voice assistants where available, including straightforward commands such as power on/off, temperature changes, and switching profiles. With scenes, you can automate behaviours-lower limits overnight, a safer mode for guests, or eco presets on working days. For families, a child-safe maximum temperature lock helps prevent sudden spikes if someone changes the flow rate.

Smart-home tip (often overlooked)

If you already use Xiaomi scenes elsewhere, it can be worth tying hot-water presets to existing routines (wake-up, bedtime, “away”, or “guest mode”). Comfort improvements usually come from consistent, repeatable settings-rather than chasing the lowest possible temperature day by day.

Sizing and installation notes worth knowing

Point-of-use units perform best when they’re chosen for a specific job. A small hand-basin needs far less flow-and often a smaller temperature rise-than a rainfall shower. If you’re renting, confirm what you’re allowed to change before touching plumbing or electrics. Many compact heaters require a dedicated electrical circuit; check local requirements and use a qualified installer if you’re unsure. In older buildings, a quick load calculation can prevent nuisance trips at the consumer unit.

Rule of thumb: size the heater for the flow rate and temperature rise you need, not for the whole home.

A quick sizing example (typical, not model-specific)

Imagine your cold water arrives at 12°C and you want 38°C at the shower-an increase of 26°C. A modest shower head might run at around 6–8 litres per minute. Many point-of-use electric heaters that can hold that temperature at that flow sit in the mid-to-high kW range. For a single sink at 3–4 litres per minute, lower power is often enough. Exact figures vary by region and kit, but the principle stays the same: flow rate × temperature rise dictates the electrical load.

Maintenance checklist

Rinse or replace the anti-scale filter on schedule, adjusting for local water hardness.
Run the app’s cleaning cycle if the temperature starts drifting or flow drops.
Check hoses and fittings after the first week, then every few months.
Keep ventilation around the unit clear to avoid heat build-up inside the cupboard.

Who benefits most

Studio flats and smaller homes where the main hot-water cylinder sits far from the kitchen or bathroom.
Secondary sinks, garden rooms, garages, and annexes with long or impractical hot-water runs.
Households trying to cut idle energy use and water waste without re-plumbing the entire system.

In hard-water areas, pairing the unit with a small anti-scale cartridge can help protect the heating element and keep flow consistent. If you’re integrating it into a smart home, plan around real routines-morning presets, guest safety caps, and a weekend profile often deliver more comfort than obsessing over the absolute lowest temperature. And keep coming back to placement: an under-sink install saves space, but the shortest, straightest route to the outlet will nearly always feel faster and hold temperature better.