A fuel connection unit (10) for a fuel-operated vehicle heater (18) includes a connection unit body (12), which can be arranged at a heater housing (16). A fuel release line connection area (32) connects a fuel release line leading to a combustion chamber. A fuel feed line connection area (46) projects from the connection unit body (12) for connecting a fuel feed line. At least one functional unit (50), for influencing the flow of fuel in a fuel flow volume (36) formed in the connection unit body (12), is provided in the connection unit body (12).

A fuel gas-operated vehicle heater includes a burner area with a combustion chamber (60) formed in a combustion chamber housing (58). The combustion chamber housing (58) includes a circumferential wall (62) defining the combustion chamber (60) in relation to a housing longitudinal axis radially outwards and a bottom area (64) axially defining the combustion chamber (60). The bottom area (64) has a fuel gas feed chamber (116) between a first bottom wall (106) defining the combustion chamber (60) and a second bottom wall (112). A fuel gas feed line (118) opens into the fuel gas feed chamber (116). A fuel gas inlet opening assembly is provided in the first bottom wall (106) for the entry of fuel gas from the fuel gas feed chamber (116) into the combustion chamber (60).

An evaporator assembly (10), in particular for a fuel-operated vehicle heater (12), comprising a pot-like evaporator reception (14), an evaporator body (16) inserted into the pot-like evaporator reception (14), a plate-like designed hold-down element (18), which is fixed to the evaporator reception (14) and fixes the evaporator body (16) in the evaporator reception (14), and wherein the plate-like designed hold-down element (18) has at least one retaining claw (22), which has an upper part (26) on an upper side (24) of the plate-like designed hold-down element (18) and a lower part (30) on a lower side (28) of the plate-like designed hold-down element (18), wherein the upper part (26) and the lower part (30) point away from the plate-like designed hold-down element (18).

A fuel connection unit for a fuel-operated vehicle heater includes a connection unit body (12) to be mounted on a heater body (78). A fuel release line connection area (16) is positioned such that it meshes with or faces an interior (80) of the heater body (78). The fuel release line connection area (16) connects a fuel release line (104), extending in the interior (80), with a fuel feed line connection area (20) to be positioned exposed on an outer side of the heater body (78), for connecting a fuel feed line.

A vehicle heater includes a heater housing (12) elongated in a direction of a housing longitudinal axis (L). A housing circumferential wall (34) defines a combustion air flow space (40). A combustion chamber assembly unit (14) is carried on the heater housing and has a combustion chamber (20) receiving combustion air from the combustion air flow space. A combustion air blower (42), with a combustion air blower housing (44), is carried on the heater housing. A combustion air inlet opening (56), in the combustion air blower housing, provides the inlet for combustion air into the combustion air blower. A combustion air connection unit (64), carried on the heater housing, has a combustion air passage duct (74) open outwardly in a first duct opening area (76) for receiving combustion air. The combustion air passage duct is open towards the combustion air inlet opening in a second duct opening area (78).

A method for operating a fuel-operated vehicle heater, wherein after receipt of a switch-off signal by a control unit of the fuel-operated vehicle heater, a shutdown phase is initiated, during which remaining fuel present in the fuel-operated vehicle heater is combusted, and wherein a restart phase is initiated by the control unit after receipt of a switch-on signal during the shutdown phase, without the shutdown phase being terminated after complete combustion of the remaining fuel.

A fuel-operated vehicle heater includes a burner area (12) with a combustion chamber (14); a fuel pump (24); and a combustion air blower (28). A pressure sensor (38) detects a feed back pressure. An actuating unit (36) actuates the fuel pump (24) with a predefined value of a pump operating variable, and actuates the combustion air blower with a predefined value of a blower operating variable. A heater process includes detecting the feed back pressure in case of a feed operating state set during the combustion operation and comparing the detected feed back pressure (P.sub.e) with an expected feed back pressure (P.sub.E) for the set feed operating state. If the detected feed back pressure deviates from the expected feed back pressure the pump operating variable is changed such that the feed back pressure changes toward the expected feed pressure and/or essentially corresponds to the expected feed back pressure.

A vehicle temperature control system, for electric motor-powered vehicles or hybrid vehicles, includes a heater (18), which can be operated electrically or/and with fuel, with a first heat exchanger device (16) for transferring heat provided in the heater (18) to a first heat carrier medium provided in a first heat carrier medium circuit (12). An operating material tank (20) holds a liquid operating material (24). A second heat exchanger device (26) provides heat transfer between the first heat carrier medium provided in the first heat carrier medium circuit (12) and energy storage material (36) contained in the operating material tank (20). A third heat exchanger device (38) provides heat transfer between the first heat carrier medium provided in the first heat carrier medium circuit (12) and a second heat carrier medium provided in a second heat carrier medium circuit (40).

A combustion chamber assembly unit for a fuel-operated vehicle heater includes a mixing chamber (20) extending in a direction of a combustion chamber assembly unit longitudinal axis (L) for generating an air/fuel mixture. A fuel feed device (38) feeds fuel to the mixing chamber (20) and a combustion air feed device feeds combustion air to the mixing chamber (20). A diffuser device (22) is arranged downstream in relation to the mixing chamber (20) in the direction of the combustion chamber assembly unit longitudinal axis (L). The fuel feed device (38) includes an evaporator device (36). The combustion air feed device (18) includes a swirling flow generation device (14). The swirling flow generation device (14) is arranged with the evaporator device (36) upstream in relation to the mixing chamber (20) in the direction of the combustion chamber assembly unit longitudinal axis (L).

A method to operate a fuel-operated vehicle heater comprising the lowering of a combustion air ratio λ between supplied combustion air and supplied fuel to a combustion chamber of the fuel-operated vehicle heater from a starting value λ.sub.start>1 to a range λ<λ.sub.start for a time period Δt.