Vehicular heater

A vehicular heater mounted on a vehicle having a power unit, the vehicular heater comprising:

• a blower that blows vent air into a vehicle compartment which is a space to be heated;
• a heat medium circuit connected to a heater core that heats the vent air blown by the blower via heat exchange with a heat medium;
• a pump that circulates the heat medium in the heat medium circuit;
• a valve configured to switch the heat medium circuit;
• and
• a controller configured to control the valve and the pump, wherein
• the heat medium circuit includes:
• a first flow path connected to the heater core through the power unit;
• and
• a second flow path arranged in parallel with the first flow path and connected to the heater core through a heat source device different from the power unit,
• the valve switches the heat medium circuit such that:
• when the power unit is operating, the first flow path includes a circuit bypassing the heat source device;
• and
• when the power unit is not operating, the second flow path includes a circuit bypassing the power unit,
• the valve is disposed in the heal medium circuit at a position different than a position of a connecting portion that connects and is between the first flow path and the second flow path,
• the controller controls the valve and the pump to adjust a first flow rate of the heat medium flowing into the first flow path and a second flow rate of the heat medium flowing into the second flow path, and
• when the power unit is operating, the controller:
• controls the valve and the pump such that the heat medium flows in both the first flow path and the second flow path;
• and
• adjusts the second flow rate to a flow rate determined for reducing a thermal shock load in the second flow path.