potty on carpet

Question
I moved to a apartment where the previous owner had a dog.  My dog has the tendency to pee on the carpet because he can smell the scent.  I have bought a gate to keep him from going in my living room, I have purchased a crate which I use when I'm at work.  I hate to see him in the crate so much but I can't trust him outside of it.  He will go to the bathroom at night while I'm asleep.  I take him outside 3 - 4 time per day.  I am considering having the carpet cleaned again. Do you think this will help eliminate my problem?  He is 2 years old and part terrier.  I really love him but I'm getting discouraged with this problem because it seems to have gotten worse since I've moved into my apartment.  HELP!!

Answer
First of all, try to change your thinking concerning the crate.  If used properly, and NOT as punishment, your dog will enjoy his crate.  Dogs like having a small area to "hole" up in; it makes them feel safe and protected.

You are correct in that any remaining scents of urine or stool will counteract your attempts at housebreaking.  I am including information here on removal of stains.

My suggestion would be to crate him whenever you are not able to supervise his behavior, especially when you are not at home.  If you continue to "feel sorry" for him when he's crated, consider giving him something like a Nylabone or Kong in his crate in case he gets bored:

http://www.marinhumanesociety.com/Behavior/Handouts/KongsHomeAlone.pdf

http://www.hsmo.org/m_obedience/behavior/dogcrate.html
http://www.ddfl.org/behavior/crate-train.pdf

http://www.ddfl.org/behavior/clean-stains.pdf
http://www.hsmo.org/m_obedience/documents/CanineHousesoilingProblems.pdf
http://www.ddfl.org/behavior/retrain-dog.pdf
http://www.ddfl.org/behavior/pup-housetrain.pdf
http://www.marinhumanesociety.com/Behavior/Handouts/Housetraining.pdf