The HDG Compact is a fully automatic wood chip and pellet boiler from HDG Bavaria in Germany, with models from the Compact 30 to the Compact 149. Automatic ignition and integrated combustion and output control come as standard, and a buffer tank management system is available.

Fuel burns on an air cooled tilting grate in a hot, modular combustion chamber, which keeps the output even. Lambda, flue gas and combustion chamber sensors control the primary and secondary air, and the welded boiler body is made from 4 to 5 mm steel plate with an integrated safety heat exchanger.

Two augers move the ash into external containers, either two 40 litre bins or one 230 litre container, and an automatic cleaning system keeps the boiler clean. The boiler can be supplied with HDG feeding systems, including a pellet suction system, is available with the feed on the left or the right, and is type tested to DIN EN 303-5.