Shanghai Jastar Industrial Co., Ltd.
Booster pump · Dual knob 3,500 / 5,500 W Built-in booster pump Shower set included OEM / ODM

5.5 kW Instant Electric Water Heater — Dual Knob Control, Built-in Booster Pump

A 210 × 65 × 340 mm wall unit with a built-in booster pump — it draws from a roof tank or a weak main and still holds a usable shower. Two knobs keep the jobs separate: one sets the outlet between 30–55 °C, the other sets pump speed. 3,500–5,500 W stainless steel cup element, hot water in about two seconds, shower set in the box.

Model
GB-12
Rated power
3,500 / 5,500 W
Voltage / Frequency
110 / 220 V ~ · 50 / 60 Hz
Heating element
Stainless steel cup, 5.5 kW
Hot water in
≈ 2 seconds
Temperature range
30 – 55 °C
Control
Dual knob — temperature and pump
Booster pump
Built-in · 0.02 – 0.6 MPa
Power cable
≥ 2.5 mm² copper core
Unit size
210 × 65 × 340 mm
Carton
12 pcs · 645 × 380 × 590 mm · 38 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

Built-in pump, two knobs, no plumbing surprises

For properties where shower pressure — not heating power — is the real problem.

Built-in booster pump

Built-in booster pump

A pump inside the case lifts supply pressure across a 0.02–0.6 MPa working range, so a tank on the roof or a long run of small-bore pipe no longer means a dribbling shower.

Shower set in the box

Shower set in the box

The unit ships with the riser rail, hose and hand shower, so one order covers the whole installation instead of three purchase orders.

2.5 mm² copper cable

2.5 mm² copper cable

Specified for ≥ 2.5 mm² copper core — check the circuit before quoting, because a 5.5 kW load on 1.5 mm² is the most common failure in retrofit bathrooms.

What the pump actually fixes

What the pump actually fixes

The comparison in the gallery shows the same unit with and without the booster: weak flow and a cold-start trip on one side, stable flow on the other. That is the conversation to have with a buyer who has already tried a pump-less heater.

Specifications

Technical data — GB-12

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, 5.5 kW
Heating time≈ 2 seconds
Temperature range30 – 55 °C
ControlDual knob — temperature and pump speed
Booster pumpBuilt-in · 0.02 – 0.6 MPa working range
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 size210 × 65 × 340 mm
Inner box370 × 105 × 290 mm
Pcs per carton12 pcs
Carton size645 × 380 × 590 mm
Gross weight38 kg
Shower setIncluded
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.

Product details

Full product presentation

GB-12 multi-point hot water supply diagram for shower, basin and kitchen GB-12 shown across six installation scenarios GB-12 product information table: power, voltage, IPX4 and element GB-12 dimension drawing, packing size and carton loading

Request a quotation for GB-12

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.