I have a hotpoint double oven. The lower oven is not heating up at all. When it was swithched on yesterday we blew a circuit and the oven has not worked since then. The smaller upper oven continues to work. Help. Cheers

Most likely the heating element shorted against its grounded shield. It will have to be replaced. You can check this using an ohmmeter. Normally you disconnect the range from the wall or throw the circuit breaker (very important unless you have a death wish). Use the multimeter on the 240 volt AC scale to make sure the power has been turned off. After doing that, check the multimeter on a live circuit to make sure that it's working. Disconnect one side of the power going to the heating element and then switch the multimeter to a low ohm scale. The resistance should be below about 25 ohms. If it's burned out, it will have infinite resistance and one of the two sides will probably show a relatively low resistance to the shield (but you may have trouble getting one of the prods to connect to the shield).

Replacement should be pretty obvious once you've seen how it's put together.