Should it take 4 hours to bake one loaf of bread in a machine?

The machine is not working, temperature must be bust. No loaf of bread takes 4 hours to bake. The only thing would be that the temperature is not right.

Until you get a new one, you can always just use it to prep the dough and then bake your bread in the oven, the old fashioned way.

Get yourself an oven thermometer (they're not that expensive) and test the temp of your bread machine. Also use it to calibrate your oven- always a good idea to do, not all ovens are the same, some are off by as much as 50-75 degrees, which can mean success or failure for baking.

I seem to remember my B&D bread machine taking 3 hours 50 minutes. Over 3 hours, at least. If the loaf is small and hard, you must be doing something wrong. Are you following a recipe that came with the machine, using the exact ingredients called for? Measuring correctly? Adding things in the right order? Using yeast that's the right kind and still good?

Possibly, if I remember correctly a bread machine mixed the ingredients for the dough, then kneads the dough, the dough then has to rise which can take a few hours and then is baked. Sometimes the dough is kneaded and/or the dough has to rise twice.