The reliability of heaters in G8DA, G8DB code motors installed in Focus is great. This is factory size of heating module for 2003 Ford Focus with G8DA, G8DB engine. During winter using of Ford Focus heat exchanger is in operation. If you need to replace it, buy 180 mm height, 238 mm width and 43 mm in depth equipment. Interior climate control in 2003 cars with 1.6 volume of engine is efficient.
If the device is broken, you may find in 1.6 Focus interior some lack of coolant. While repairing Ford Focus 1.6 purchase radiator with 180 mm X 238 mm X 43 mm (height, width, depth). One more problem in 2006 year of production Ford is bad heating.