When measuring the voltage of coolant what is the limit before the system needs to be flushed?

The voltage of coolant should generally be below 0.3 volts to ensure it is not excessively corrosive. If the voltage exceeds this threshold, it indicates the presence of electrical conductivity that can lead to corrosion and damage to the cooling system components. Regular monitoring and flushing the system when voltage rises above this limit can help maintain system integrity and prevent costly repairs.