Sourcing immersion-heater timers from China

UK duty on synchronous-motor heater timers

Read from the UK Trade Tariff on 4 October 2026, heading 9107 covers time switches with clock or watch movement or with synchronous motor. Synchronous-motor immersion-heater time switches fall within the supplied line 9107 00 00 90, carrying 4% duty for goods from China. The extract lists no anti-dumping or countervailing duty and no suspension. It contains only this commodity line.

The UK Trade Tariff attaches a DCMS Export Licence control to this code. Its note provides a document waiver for goods manufactured or produced less than 50 years ago, or falling within the stated exceptions. Ask your customs broker to confirm how this entry and any document waiver should be handled for the shipment.

Confirm the commodity code using the actual timing mechanism and product specification. A digital timer without a clock movement or synchronous motor may fall under heading 8536 instead. See the wider timer switches guide for other formats.

Specify the motor, heater load and terminals

Specify a synchronous-motor timing mechanism, supply voltage and frequency, resistive heater-load rating, switching interval and programme arrangement. Agree the dial direction, switching segments, manual override and behaviour after a power interruption. Include mounting dimensions, cable-entry positions, terminal capacity and a wiring diagram. Confirm whether the timer switches the heater directly or operates a separate contactor.

Confirm with the relevant authority how the Electrical Equipment (Safety) Regulations 2016 apply to mains timers, including declaration of conformity, CE or UKCA marking and importer identification requirements for Great Britain. Obtain the declaration of conformity and matching safety reports, and check the marking and importer identification. Instructions must be in easily understandable English. Ask for restricted-substance compliance documentation: electrical equipment is within the hazardous-substance rules unless specifically excluded.

Check whether the design falls within the electromagnetic compatibility rules, which cover equipment liable to generate electromagnetic disturbance, subject to exceptions. Waste electrical equipment obligations also apply; producers must register annually. Resolve documentation and registration before sale, with support from testing and certification.

Worked duty example

Illustrative example, not a quote: 1,000 synchronous-motor immersion-heater time switches, illustrative order under 9107 00 00 90, invoiced at £25,000 free on board, with £1,500 of freight and insurance to the UK. The customs value is £26,500. Duty at 4% is £1,060. Import VAT at 20% is charged on the customs value plus duty, £27,560, so it is £5,512. Import taxes total £6,572; a VAT-registered importer can usually reclaim the VAT, so the lasting cost is the £1,060 of duty. The import duty and VAT guide explains each step.

Inspection checklist

Timing: compare dial travel with a reference clock, run the agreed switching programmes and check manual override and restart behaviour after a power interruption.

Heater load: test samples at the agreed resistive load, looking for excessive heating, intermittent switching or contacts that remain closed after the timer switches off.

Terminals and enclosure: compare terminal markings with the wiring diagram, check screw retention and cable access, and inspect the dial, switching segments, cover and mounting points for damage.

Documents and labels: match the model, load rating and supply details to the declaration and test reports; check conformity marking, importer details and English instructions. Use the quality inspection guide to agree the inspection scope.

What goes wrong

A timer can keep time on the inspection bench yet overheat when switching an immersion heater. Weak contacts, loose terminals and an unsupported heater-load rating are the failures to target. Dial segments can break or move, and a poorly retained override can leave the heater running.

A motor intended for a different supply frequency can upset the programme timing. Agree the intended supply and test it on the approved sample. Keep that sample alongside the wiring diagram and component specification, and compare production units before shipment.

Cambridge China Bridge sources these products for UK businesses, checking the factory and the documents before shipment. See factory verification. For own-brand ranges, see sourcing for brands.