Abstract: A device using oil for heating the operator's cab of a machine driven by an air-cooled internal combustion engine, especially the operator's cab of a vehicle. The lubricating oil of the internal combustion engine is recooled in an oil cooler and is entirely or partially branched off from the oil cooler and is fed through valves, regulating and control devices to a heat exchanger in the operator's cab. The device includes a manually adjustable rotary valve for opening and closing the heating system together with two oil pressure dependent bypass valves in the heating circuit and with a bypass valve for a lubricating oil filter from a compact valve block. The valve block together with a support for the lubricating oil filter is designed as a one-piece housing and is flanged to the machine housing. Connecting bores for the supply and return conduits to the heating system in the operator's cab are arranged in the one-piece housing.