Abstract: A heat generator comprising at least one thermal module comprising a magnetocaloric element crossed by a heat transfer fluid and two hot and cold chambers arranged on each side of the magnetocaloric element and containing a displacement device for directing the heat transfer fluid through the magnetocaloric element. A magnetic arrangement creates a magnetic field variation in each magnetocaloric element. A device for driving the displacement device, according to reciprocating movement in the concerned chamber, to displace the heat transfer fluid in synchronization with the magnetic field variation. The drive device contains a closed fluid circuit which connects the hot and cold chambers in which a working fluid is driven by a suction and discharge device. At least one switching interface is synchronized with the magnetic arrangement for alternately connecting each hot and cold chamber to suction and discharge sides of the suction and discharge device and inversely.