On start up is fine but within 5 minutes on red temp gauge, have checked oil water coolant doesn’t appear to have any leaks
When the temp gauge goes up into the red, lift the hood and look, and touch gently: is the motor hot?
If the motor isn't overheating, then the temperature gauge, wiring, or coolant sensor is faulty.
If, on the other hand, the motor is indeed overheating, then the thermostat has failed closed, or the waterpump has failed, or the waterpump drive belt has failed, or one of the coolant hoses or radiator has failed internally and is obstructing the flow of coolant.
@Solar Mike is quite correct: excessive heat can quickly and seriously damage the motor.