Abstract: The invention concerns a control device for gas boilers. The overall functions involving control and safety are ensured by a control box (26) with microprocessor which centralizes data collected from the ambient thermostat (27), the temperature sensor (28) on the duct (21) for heating water return, the air output sensor (19), the drawing contact (31), the extraction fan (6) speed sensor (30), and the lighter (24), and it converts them into digital signals that are made to operate the lighter, the circulation pump (19), the gas inlet electrovalve (12) and the extraction fan according to the control data that the microprocessor has memorized. Application for forced draft steamtight gas boilers.

Abstract: The invention relates to a forced draft household gas boiler having a sealed enclosure for the combustion assembly of the boiler.A sealed shell (15) envelopes a cylindrical heat exchanger (6) and is suspended in the upper half of a frame (1) from a horizontal plate (4) so that a central inlet opening (11) of the heat exchanger is in the axis of an outlet tube (32) of a fan (29) which directs an air/gas mixture into the burner. An outlet opening (23) for the combustion products collected in the sealed shell (15) is located within the circumference of the shell and at least approximately in the axis of an evacuation pipe (18) for evacuating combustion products external of the boiler.