Heat included in rent?

Hello. I’m hoping somebody can give me some help with a situation I’m dealing with.

We recently moved out of a place, and the landlord is being.. difficult so far. We are supposed to be getting our deposits back minus the outstanding gas bills, but he’s stopped responding to my emails and texts.

On our rental agreement it says heat is included in the rent, but not gas. Yet the only thing that uses gas at the house is heat. Would this mean that we aren’t legally responsible for the gas bill? Or would the RTB favour the landlord in this situation, since gas isn’t included.

I am about to email him asking for the full deposits back, but I just wanted to get an outside opinion before I send anything.

Thank you.