Hotpoint BFV620 boiling water?

As soon as my Hotpoint has filled with cold water, it's making a boiling water sound, with steam coming from the top rotor, and no water jets. The water at the bottom remains cold, so I think the recirculation pump is faulty, and the water around the element is getting over-heated due to no movement. Before I buy a new pump (£70-80), would you agree that it's likely to be the fault, or some other (?control?) problem?