Sourcing cast iron boiler sections from China
Cast iron boiler sections supplied as parts from China carry 0% UK duty; complete central heating boilers carry 2%. Check whether pressure equipment or gas appliance rules apply to the supplied section or assembly before sale. Cambridge China Bridge sources cast iron boiler sections.
0% duty on cast iron boiler parts
Heading 8403 covers central heating boilers and their parts, excluding boilers of heading 8402. This guide concerns cast iron sections supplied as boiler parts. The table includes the other heading lines for classification comparison; they do not describe alternative codes for the same cast iron section.
Read from the UK Trade Tariff on 1 October 2026, cast iron boiler parts under 8403 90 10 00 carry 0% duty on goods from China. Complete boilers carry 2%, while other-material boiler parts carry 0%. The supplied snapshot lists no anti-dumping or countervailing duties, suspensions or attached import controls.
Give your customs broker the drawings, material description and packing list, stating whether you are buying loose replacement sections or an assembled boiler. Confirm the commodity code before ordering. For complete equipment, see central heating boilers.
| Goods | Commodity code | Duty | Anti-dumping or countervailing duty on China |
|---|---|---|---|
| Cast iron central heating boiler parts, including replacement sections | 8403 90 10 00 | 0% | None |
| Other-material central heating boiler parts, for comparison | 8403 90 90 00 | 0% | None |
| Complete cast iron central heating boilers, for comparison | 8403 10 10 00 | 2% | None |
| Other complete central heating boilers, for comparison | 8403 10 90 00 | 2% | None |
Section drawings, mating joints and compliance scope
Specify the boiler model, drawing revision, cast iron grade and whether each casting is a front, intermediate or rear section. Agree waterway geometry, wall thickness, nipple seats, joint faces, tie-rod positions, threads and machining tolerances. Identify the seals and connecting nipples to be supplied. Approve a sample assembled against the intended mating sections.
Pressure equipment safety rules cover equipment and assemblies with maximum allowable pressure above 0.5 bar. Ask a compliance adviser to establish the scope for your supplied section or assembly. Gas appliances and fittings within scope require conformity assessment. Agree the applicable compliance route before sale, using testing and certification support.
Worked duty example
Illustrative example, not a quote: Illustrative order: 40 replacement cast iron boiler sections under 8403 90 10 00, invoiced at £8,000 free on board, with £1,200 of freight and insurance to the UK. The customs value is £9,200. Duty at 0% is £0. Import VAT at 20% is charged on the customs value plus duty, £9,200, so it is £1,840. With no duty, the only import tax is the VAT, which a VAT-registered importer can usually reclaim. The import duty and VAT guide explains each step.
Inspection checklist
Casting condition: check for cracks, visible porosity, cold shuts, blocked waterways and grinding repairs. Match material reports and casting identification to the agreed specification.
Joint fit: measure nipple seats, joint-face alignment, threads and tie-rod holes against the drawing. Trial-assemble samples with the intended seals and mating sections.
Leak testing: agree a hydraulic test method, pressure, hold time and acceptance criteria with the boiler designer. Record results against identifiable sections and check assembled joints.
Arrival and packing: check for cracked lugs, chipped edges, rust and damaged joint faces after unpacking. Match section types and quantities to the packing list and retain batch identification.
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What goes wrong
A casting can resemble the original while its nipple seats or waterways differ. The result can be a joint that will not seal or a section that cannot be assembled with existing stock. Porosity can cause leakage, while inadequate separation inside crates can leave edges and mounting lugs damaged.
Freeze the approved drawing and mating sample before production. Require approval for material changes and casting repairs, and repeat fit and leak checks after changes. Agree which records accompany each batch and use a written inspection brief before shipment.
Cambridge China Bridge sources these products for UK businesses, checking the factory and the documents before shipment. See factory verification. For machinery and equipment, see machinery imports.
Frequently asked questions
What is the UK import duty on cast iron boiler sections from China?
Sections supplied as cast iron boiler parts under 8403 90 10 00 carry 0% duty. Complete central heating boilers carry 2%. The snapshot lists no anti-dumping or countervailing duties.
Do cast iron boiler sections need CE or UKCA marking?
Establish the applicable product rules and assessment route for the supplied section or assembly before specifying a marking. Gas appliances and fittings within scope require conformity assessment.
Can a Chinese factory copy an existing boiler section?
Use an approved drawing and mating sample. Check waterway geometry, wall thickness, nipple seats and joint alignment rather than accepting an external resemblance.
How should I inspect replacement boiler sections?
Check casting defects, dimensions and joint fit, then follow the hydraulic test method agreed with the boiler designer. On arrival, check for transit cracks, rust and damaged joint faces.