Shanghai Jastar Industrial Co., Ltd.
Instant · Under-sink 3,500 / 5,500 W 110 / 220 V 30 – 55 °C OEM / ODM

5.5 kW Instant Electric Water Heater — Under-Sink and Basin, Copper Ports

A 140 × 60 × 180 mm unit at 1 kg, built for the points a storage heater does not reach: bathroom sinks, kitchen sinks, laundry taps and office washrooms. 3,500–5,500 W across 110 V and 220 V, copper inlet and outlet, outlet held between 30–55 °C.

Model
GB-21
Rated power
3,500 / 5,500 W
Voltage / Frequency
110 / 220 V ~ · 50 / 60 Hz
Heating element
Stainless steel cup, 3.5–5.5 kW
Hot water in
≈ 2 seconds
Temperature range
30 – 55 °C
Control
Rotary knob with LED display
Water ports
Copper inlet and outlet
Power cable
≥ 2.5 mm² copper core
Unit size
140 × 60 × 180 mm
Carton
24 pcs · 565 × 485 × 390 mm · 26 kg

MOQ 100 pcs for custom panel colour, pattern and logo · 1,000 pcs for custom packaging. Samples from 1 pc — the sample price is higher than the bulk price, and we refund the difference once you place a bulk order within 30 days of receiving the sample. Prices are quoted per order, EXW Shanghai — tell us your quantity and destination port and we will reply within one working day.

CE RoHS 100% tested before shipment

Why this model

One unit for sink, basin and laundry

1 kg, 140 mm wide, copper ports, 24 to a carton.

Sink, basin, laundry, office

Sink, basin, laundry, office

The mounting and the 1 kg body suit cupboards and vanities. 24 pieces to a 26 kg carton keeps the landed cost per piece low.

Copper inlet and outlet

Copper inlet and outlet

Copper ports rather than plated fittings, which is what the trade asks for on point-of-use units in hard-water areas.

3,500–5,500 W, two seconds

3,500–5,500 W, two seconds

Available as 110 V and 220 V from the same body, with water reaching temperature in about two seconds.

Multi-application by design

Multi-application by design

Reverse-osmosis points, utility rooms, staff kitchens and small offices are all covered by the same unit and the same spares.

Specifications

Technical data — GB-21

Every unit is pressure-tested and function-tested before packing. Custom panel finish and power connection available for OEM orders.

Electrical & performance
Rated power3,500 / 5,500 W
Rated voltage110 / 220 V ~ · 50 / 60 Hz
Heating elementStainless steel cup, 3.5–5.5 kW
Heating time≈ 2 seconds
Temperature range30 – 55 °C
ControlRotary knob with LED temperature display
Water portsCopper inlet and outlet
Power cable≥ 2.5 mm² copper core
Power connectionPlug standard to order (EU / US / UK / AU / Africa)
ProtectionWater–electricity separation · Over-temperature protection · Dry-heat protection · Leakage protection
Waterproof ratingIPX4
CertificationCE · RoHS
Water, dimensions & packing
Unit size140 × 60 × 180 mm
Inner box240 × 100 × 200 mm
Pcs per carton24 pcs
Carton size565 × 485 × 390 mm
Gross weight26 kg
LoadingLCL and FCL both available

OEM & ODM

Make it your own brand

We build for importers, wholesalers and own-brand retailers — from a panel colour change to a fully customised product and gift box.

Panel colour, pattern & logo

Body colour and front panel in your colour and pattern, with your logo printed or laser-etched. Artwork proof before mass production.

MOQ 100 pcs

Packaging

Custom printed inner box and master carton, colour or gift box, barcode and retail labelling. Export cartons are drop-tested.

MOQ 1,000 pcs

Power connection

Plug standard (EU / US / UK / AU / Africa) and cable length matched to your market. Shower set included or optional as listed above.

No extra MOQ

Documents & certification

CE and RoHS test reports, product photos, specification sheets and packing lists for your own listings and customs clearance.

Ready to share

Samples & price protection

Test one unit before you commit to a container

Every model is available as a sample, and every price step you reach is paid back to you — the sample itself included.

Samples from 1 pc

Order a single unit to test it, open it up and show your own customers. No minimum quantity, any model in the range, shipped with its CE and RoHS test reports.

MOQ 1 pc

The sample price difference comes back

A single unit is charged above the bulk price, because of one-off handling and air freight. Place a bulk order for the same model within 30 days of receiving the sample and we refund the difference.

30-day rebate

Earlier shipments are rebated too

Our four price tiers — 10–99 / 100–999 / 1,000–9,999 / 10,000+ pcs — are counted cumulatively over the 30 days after you receive the goods. Reach a higher tier and we refund the difference on the units you have already shipped.

Cumulative over 30 days

Tell us which model you want to test and we will send the sample invoice the same working day.

Request a quotation for GB-21

Send us your quantity, destination port and power connection requirements — we will come back with prices and lead time within one working day.

Product Catalog 2026

Browse the full range — instant water heaters, hot water taps and bathroom & desk heaters — in one PDF.