What is the fuse rating for 3kw immersion heater?

The fuse rating for a 3kW immersion heater is typically 13 amps. This is based on the formula that calculates the current draw (I) using the power (P) and voltage (V): I = P/V. For a standard UK voltage of 230V, a 3kW heater would draw approximately 13 amps. It's important to ensure that the circuit is also properly rated to handle the load.