The hydronic controls markets in France, Germany, Italy, Poland, and the United Kingdom are amongst the most developed in the world, collectively worth some € 2bn. Germany accounts for one third of the market value of these five important country markets, closely followed by the UK. The less developed Italian market is about half as big again, whilst France, whose nuclear power infrastructure means that there is a much smaller market for hydronic controls, accounts for just over one tenth of the market. Poland, with the smallest population of the countries studied and whose market is considerably less mature is only fractionally smaller than that of France. Control valves make up the lion’s share of the market by value, followed by radiator valves but these ratios are reversed when assessed by volume of units sold. By contrast, controllers and room thermostats account for only approximately 20% of the market value.