Fluid heater with freeze protection

A heater apparatus for heating fluid, the heater apparatus comprising:

• a thermally conductive mass;
• a fluid flow path formed of a first flow path portion extending across one surface of the thermally conductive mass and a second flow path portion extending across an opposed surface of the thermally conductive mass, the first and second flow path portions disposed in fluid flow communication through the thermally conductive mass, the fluid flow path defined by open-ended channels formed in the thermally conductive mass, the open-ends of the channels facing outward from the thermally conductive mass;
• at least one heating element thermally mounted in the thermally conductive mass and substantially contacted by the mass, the heating means imparting heat to the thermally conductive mass so that fluid in the first and second flow path portions absorbs heat from the thermally conductive mass;
• control means, including power switch means connected to the at least one heating element, for activating the at least one heating element;
• a housing carrying the thermally conductive mass in an interior cavity;
• and
• fluid expansion means mounted on the mass for reversibly allowing phase change expansion of fluid in the fluid flow path when the fluid is in at least a substantially solid state.

A vehicle window wash apparatus comprises:

• a fluid source for supplying wash fluid;
• a fluid discharge device fluidically coupled to the fluid source for discharging fluid from the reservoir;
• a heater means disposed in fluid flow communication between the fluid source and the fluid discharge device;
• a controller, coupled to the heater means for supplying power to the heater means;
• the heater apparatus including:
• a thermally conductive mass having an inlet and an outlet;
• a fluid flow path formed in the mass between the inlet and the outlet, the fluid flow path substantially enveloping the heating means so that fluid in the fluid flow path absorbs heat from the thermally conductive mass;
• control means, connected to the heating means, for activating the heating means;
• the fluid flow path open to the exterior of the thermally conductive mass;
• a housing carrying the thermally conductive mass in an interior cavity;
• and
• fluid expansion means carried in the housing for reversibly allowing expansion of fluid in the fluid flow path when the fluid is in at least a substantially solid state.