An under-sink water heater is not a smaller version of a whole-home unit. It is a different product doing a different job.

If you are shopping for an under sink water heater, the appeal is easy to see: put the heat where the water comes out and the wait disappears. What decides whether it works has little to do with the brochure — it is the circuit, the cabinet and the incoming water temperature.

Anlabeier, the instant electric water heater brand of Zhongshan Chongde Electric Co., Ltd., builds point-of-use and whole-home units on the same platform, which is why the checks below apply whether you are fitting one tap or a whole house.

Why People Put a Heater Under the Sink

• The distance between the heater and the tap is the reason hot water takes time. A unit under the sink removes that distance.
• Water sitting in a long pipe run between uses cools down and is then poured away. A point-of-use unit has no such run to lose heat into.
• Kitchens and guest bathrooms usually need hot water at one tap, not five. That is a sizing question, not a quality question.

Recommendation: decide what the tap is for before you compare models. A kitchen sink used for washing up and a guest bathroom used for a quick shower place different demands on flow.

Check 1 — Match the Power to the Outlet, Not the Room

An instant heater raises the water temperature as it passes, so colder inlet water needs more power to reach the same setpoint at the same flow.

• A unit at the low end of the range — Anlabeier's starts at 3.5 kW — suits a single outlet at modest flow.
• If that tap has to fill a sink quickly while the inlet water is cold, a larger unit buys flow, not luxury.
• Two outlets on one small unit is not a sizing trick; it is a complaint waiting to happen.
• Sizing by room size instead of by outlet is a common mistake in this category.

Recommendation: size for the coldest inlet water you see in the year, and for one tap at a time. If you are choosing for a whole property rather than a single sink, the walkthrough in Apartment, Villa, or Rental? How to Pick the Right Tankless Water Heater for Your Home covers the bigger picture.

Check 2 — The Electrical Supply Decides What Fits

This check stops many under-sink projects, and it has nothing to do with the cabinet.

• A 3.5 kW unit at 230 V draws roughly 15 A. That is not a plug-in appliance load.
• Many installations need a dedicated circuit and a protective device; what is required exactly depends on your local wiring rules.
• Wiring, breaker changes and earthing are work for a licensed electrician.
• If the unit includes ELCB or RCD protection, test it at the interval the manual gives.

Recommendation: get the electrician's answer before you order. "There is a spare way in the board" is worth more than any specification comparison.

Check 3 — Measure the Cabinet, Then Measure the Clearance

Under-sink cabinets are built for bottles, not for appliances.

• Measure height, width and depth with the pipes and the trap in place, not with the cabinet empty.
• Leave the service clearance the manual asks for; a unit boxed in against a shelf cannot be maintained.
• Kitchens and bathrooms are damp rooms. Check that the IP rating suits the location — IPX4 splash resistance is worth looking for in this position.
• Do not mount the unit against a heat source, or where a leak would run onto wiring.

Recommendation: photograph the cabinet with a tape measure in frame before you shop. It saves a return.

Check 4 — Point of Use Water Heater vs a Small Storage Tank

Both fit under a sink. They fail in different ways.

Recommendation: choose the instant unit when the circuit can carry it and the tap is used regularly. Choose the tank when the electrical supply cannot be upgraded.

Check 5 — Water Quality and the Scale Question

A small unit works harder in a hard-water area, because the element is the hottest surface in the system and scale settles there first.

• Scale insulates the element: the unit runs longer for the same result, and performance drops quietly.
• Descaling is routine, not a repair. Hard Water and Your Tankless Water Heater: A Descaling Guide walks through it.
• If your water is very hard, plan the descaling interval before installation, not after the first cold shower.

Installation: What the Job Actually Involves

• Water side: shut off the supply, connect to the cold inlet, check for leaks, flush before use.
• Electrical side: dedicated circuit, protective device, earthing — licensed electrician.
• Tankless Water Heater Installation: DIY or Call a Pro? sets out which parts of this are reasonable to do yourself, and the safety checklist in Water + Electricity = Danger? Not If Your Heater Passes These 5 Safety Checks is worth reading first.

Why Anlabeier Fits Under a Sink

Anlabeier is the instant electric water heater brand of Zhongshan Chongde Electric Co., Ltd., a manufacturer in Zhongshan, Guangdong, that has built instant electric water heaters since 2010. The range runs from 3.5 kW for a single outlet to 12 kW for a whole home, with stainless steel or cast aluminium heating elements chosen to cope with hard water, ELCB leakage protection, dry-heating cutoff, overheat protection and an IPX4 splash-resistant casing. The company holds more than 120 patents and works to CE, CB, RoHS, ETL and ISO9001 standards — the paperwork an installer or a distributor asks to see before a unit goes into a cabinet.

Conclusion

An under-sink heater is a small product with three large constraints: the circuit, the cabinet and the inlet water. Check those before you compare models and the choice becomes simple. Check them afterwards and you will be returning a unit that was never going to fit. Anlabeier units from Zhongshan Chongde Electric Co., Ltd. span both ends of the range, so the same checks apply whether the answer is 3.5 kW or 12 kW.

FAQ

Can a tankless water heater go under the sink?
Yes — when the cabinet has clearance, the location is not a freezing risk and the circuit can carry the unit. The circuit, not the space, is usually the limit.

Do you need a dedicated circuit for an under-sink water heater?
In many installations, yes — the load is well above what a general-purpose socket circuit is designed for. What your local rules require should be confirmed by a licensed electrician.

Is a point of use water heater worth it?
It is worth it when the wait is long and one tap is used often; it is a poor fit when the tap is occasional and the circuit cannot be upgraded.