A continuous flow regulator for vehicle heating systems includes a body configured to be connected in-line with coolant flowing through the heating coil of the heating system. A spring biased ball valve assembly is disposed in the body and is configured to restrict flow through the regulator in response to increasing flow rate of coolant and to open flow through the regulator in response to decreasing flow rate of coolant. Flow rate of coolant is therefore continuously adjusted and regulated to protect the heater core from corrosion due to high coolant flows therethrough.