Landlord's obligation to maintain house?

This property is located in Ontario. In the seven months that we have rented our home, we have had three water leaks. The latest caused significant damage to the family room, dining room, and two bathrooms. We were in a hotel for a week, followed by three weeks of waiting for the repair work to begin. We have a month of repairs in front of us. In the mean time, we have clearly not been able to have full use of the house. Not to mention the disruption of workmen in and out of the house all day. Is this cause for us to terminate our lease? Or, is this cause for us to ask for a refund from our landlord for the 3 months of the lease we have not had full use of the property?