All licensed contractors must meet the installation requirements of the CAN/ULC S705.2 Installation Standard and all the installation requirements of the manufacturer. All manufacturers listed on this web site provide a comprehensive Quality Assurance Program which you can contact if you have any questions or problems. The Quality Assurance Program acts as a conciliator to resolve all issues. The Quality Assurance Program investigates any complaints and conducts inspections. If there are any deficiencies from the Standard, the contractor must correct the deficiencies and if he is unwilling or unable to do so, the 3rd party warranty provided under the Quality Assurance Program will correct the problem up to the limits set by the Program.