A look at statistics compiled by the Gas Appliance Manufacturers Association (GAMA) indicates that heating unit shipments have been cyclical, in general, over the last five years. The numbers have bounced up and down, sometimes showing strong positive or negative swings.
Shipments then slipped 0.7% in 2000 and another 1.3% in 2001, but the output remains at more than 3 million units for the third consecutive year, suggesting that the market may have found its level for the time being.