Market evolution: Boiler parts (CN 840390) — 2015–2025

Introduction

This report examines the EU's external trade in parts of central heating boilers (customs code 840390) over the period 2015–2025. The EU has remained a major net exporter throughout the decade, with exports consistently exceeding imports by a wide margin. However, the overall surplus has narrowed, declining from approximately €463 million in 2015 to €390 million in 2025 (−15.8%), as imports grew faster (+28.3%) than exports (−7.5%). Meanwhile, EU production value in this segment surged from €760 million to €2.2 billion (+189.5%), suggesting a significant expansion of the domestic manufacturing base even as the trade balance tightened. The following sections analyse the principal dynamics behind these headline figures.

1. A Shifting Geographic Map: From the UK and Russia Towards Türkiye, China and the Western Balkans

1.1. The United Kingdom remains the EU's largest partner but is losing ground on both sides

Throughout the period, the United Kingdom was the single most important destination for EU boiler-part exports and a leading source of imports. However, both flows have declined:

The persistent erosion of bilateral trade is consistent with the structural effects of Brexit — the UK's departure from the EU single market and customs union introduced non-tariff barriers (customs formalities, rules of origin, regulatory divergence) that have gradually reoriented supply chains on both sides of the Channel. Yet the UK remains by far the top export destination and its share, while shrinking, has no single rival at comparable scale.

1.2. Türkiye has become a major two-way partner, driven by its role as a heating-equipment assembly hub

The rapid growth on both sides reflects Türkiye's expanding boiler-manufacturing sector, which imports European components for assembly and increasingly ships finished or semi-finished parts back to the EU. Notably, a sharp import price shock was detected in 2023, when the unit value of EU imports from Türkiye jumped by 37.2% (with an abnormality score of 27.9), coinciding with a period of elevated Turkish inflation and currency depreciation.

1.3. China's role has evolved from a modest supplier to a fast-growing export market

EU imports from China grew moderately (from €19.0 M to €22.5 M, +18.9%) but remain well below their 2022 peak of €49.6 M, suggesting some reshoring or diversification away from Chinese supply chains in recent years. Conversely, EU exports to China surged from €8.2 M to €33.4 M (+308.4%), making China the fastest-growing top export partner. This likely reflects the growing Chinese demand for high-efficiency European boiler components as the country expands district-heating infrastructure.

1.4. Russia's collapse as an export market mirrors geopolitical disruption

EU exports to Russia fell from €21.4 M in 2015 to just €2.9 M in 2025 (−86.3%), with a detected price shock in 2021 (unit value +48.0%). The collapse accelerated from 2022 onwards following the EU's sanctions regimes imposed after Russia's invasion of Ukraine.

1.5. Western Balkan partners have surged on both trade flows

Bosnia and Herzegovina in particular has become a notable import source, likely reflecting EU manufacturers' nearshoring strategies — leveraging lower labour costs, geographic proximity, and preferential trade access under the Stabilisation and Association Agreement.

2. A Diversifying but More Concentrated Manufacturing Landscape Within the EU

2.1. Italy, Slovakia and Germany dominate exports, but their trajectories diverge sharply

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Germany's steep decline is striking: once the second-largest EU exporter, it has been overtaken by both Slovakia and France. This likely reflects broader deindustrialisation trends in German manufacturing, rising energy costs, and competitive pressures. Slovakia's strong position is consistent with its well-developed boiler-component industry and high revealed comparative advantage (RCA of 8.75). France's rise suggests capacity expansion or product repositioning.

2.2. On the import side, Ireland and Austria have emerged as major new importers

Ireland's extraordinary import growth is notable; it went from one of the smallest importers to the second-largest by 2025. This may reflect the relocation of distribution or assembly operations to Ireland, or the impact of large-scale residential and commercial heating-system installations driven by Ireland's energy-renovation programmes.

2.3. The EU's export concentration has declined, signalling a more diversified partner base

The Herfindahl-Hirschman Index (HHI) for exports fell from 2,509 to 2,057 over the period (−18.0%). While still above the 2,500 threshold that marks "high concentration" in 2015, the EU's export structure has become less dependent on any single partner. On the import side, the HHI also declined from 1,643 to 1,396 (−15.0%), confirming a broad-based diversification of supply sources. This trend reduces vulnerability to single-country disruptions, though individual volatility — as measured by the coefficient of variation — remains high for several smaller partners (e.g., Iran, Serbia, Russia).

3. Growing EU Self-Sufficiency in Production, Yet Rising Import Reliance in Cast-Iron Segments

3.1. EU production value has nearly tripled, outpacing trade growth

According to PRODCOM data, EU production value grew from €760 million to €2.2 billion (+189.5%) over the period, with the steepest increase occurring from 2020 onwards. This expansion may reflect several factors: (i) the EU's energy transition policies (e.g., the Renovation Wave, Fit for 55) driving demand for modern, efficient heating systems and their components; (ii) rising unit prices inflating nominal production values; and (iii) post-COVID supply-chain reshoring.

3.2. The EU maintains a strong net-exporter position, with import reliance remaining negative

The net import reliance ratio has been consistently negative (indicating a trade surplus), oscillating between −17.4% and −48.1%, and standing at −21.3% in 2025. The export propensity — the share of EU production exported outside the bloc — stood at 23.2%, with the salience score indicating that export orientation is slightly more defining of this sector than trade intensity. In other words, the EU's boiler-parts industry remains structurally outward-looking.

3.3. Within the sub-product breakdown, cast-iron parts (84039010) show the fastest import growth

The heading 840390 bundles two sub-products. The vast majority of trade falls under 84039090 (general parts), but cast-iron parts (84039010) display notable trends:

The import unit price for cast-iron parts has risen from €1,654/t to €3,672/t (+122.0%), far outpacing general parts. This may reflect a shift in sourcing: as EU foundries face higher energy and environmental compliance costs, cast-iron boiler components are increasingly procured from lower-cost third-country suppliers (notably Türkiye and Bosnia-Herzegovina), driving up both volumes and unit values.

On the export side, cast-iron parts have remained a small and declining share of total EU exports, with volumes falling from 3,724 t to 1,888 t (−49.3%) over the period. This further supports the interpretation of a gradual offshoring of cast-iron component production.

Conclusion

The EU boiler-parts market (CN 840390) has undergone a quiet but significant transformation over the decade to 2025. While the bloc remains a strong net exporter — with production value nearly tripling — the trade surplus has narrowed by 16%, and the geographic centre of gravity has shifted. The United Kingdom's dominance has eroded (likely Brexit-related), Russia has virtually disappeared as a customer (sanctions), and Türkiye, China, and the Western Balkans have gained prominence as both suppliers and buyers. Within the EU, Slovakia and France have consolidated their export positions, while Germany and Italy have seen notable declines. The concentration of trade has decreased, offering greater resilience to partner-specific shocks. However, rising imports of cast-iron parts at rapidly increasing prices point to a structural relocation of lower-value-added production outside the EU — a trend that, combined with the EU's ambitious energy-renovation agenda, will continue to shape the competitive landscape for central heating boiler components in the years ahead.