I had a similar problem once with my cat.
About 5 years ago a tenant moved into our house, and she had a cat.
Unfortunentally, our cat, who had been living in the house for several years didn't take this quite as had expected her to.
In hindsight, I am at a loss to understand why our family didn't anticipate any problems with having a strange cat move in to the house, but anyway, we didn't.
So, our cat decided to protest this enchrochment into her territory by urinating in any hole she could find. She used the air vents in the floors, until we covered them. Then, she decided to use our stovetop elements. Obviously, we were not pleased. It took us a week to figure out why it smelled every time we turned on the stove, and we only figured it out then because the cat decided to relieve herself on the stove right infront of my mom.
Since then, we have gotten a new stove, but we still have the same cat.
Oh ya, we saw the cat using the stove mere days before we had to cook thanksgiving dinner.