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[COLOR="Blue"]I was told that this is the thermostat, and it was easy to replace. [/COLOR]
I doubt it is the thermostat. Even if the thermostat never opens the breaker should be able to provide enough power so that it does not trip.

I would check the heating element.
Unplug the unit and both wires at the heating element.
Measure the element, should be about 8 to 12 ohms.
Next measure from each element connector to the case/frame, both should be infinite ohms. If not the lement is grounded and need replacement.

There is also the possibility that the breaker has a problem and is tripping at too low of a current. To check this you would need a clamp on amp meter.

It can be but you have to check it.

There can be a number of causes, the heating element is just the one I think is the most likely.

If you do not own a meter, I would suggest you purchase a one. You can get a decent digital multimeter for under $20.00. You do not need fancy though it is nice if the leads are a couple feet long.
If it saves ordering one unnecessary part it has paid for itself and you end up owning a useful tool.
Most places will not let you return electrical parts so if you order it, you own it.
A couple things to watch when measuring ohms and continuity
1. Always remove power from the machine otherwise you could blow your meter.
2. Always disconnect at least one side of any device you are checking. This eliminates the possibility of measuring an alternate/parallel circuit path.
3. When checking for closed contacts and continuity use the lowest scale (Usually 200 ohms). Then try higher scales. This scale is 0 to 200 ohms so if the device you are measuring is 300 ohms this scale would show an open circuit which it is not, you are just measuring outside the scale's dynamic range.
4. When you start always short the meter leads together. This will tell you that the meter is working and if there is any 0 offset.

There is a good STICKY at the start of this forum about it's use.