How do you tell if a baseboard heater has gone bad?

It won't make heat any more. :rolleyes:

You are in the cold?

If you have a clamp on Am-Meter, you can turn the heat on and measure the current draw with the heat on and then off. Check the connections at the heater to make sure they are tight. Check the voltage at the heater.

You can even phrase your question better so we understand your problem,

Good morning, by the way.