One of the most common heating systems eligible for rate DT is the dual-energy forced air system made up of a fuel-burning forced-air system combined with a central heat pump. Although oil is the auxiliary energy source most commonly used by Rate DT customers, a compliant dual-energy system can use another type of fuel, such as natural gas or propane. To subscribe to rate DT, you must ask a heating contractor to fill out the Certificate of Eligibility – Dual Energy to certify that your dual-energy system conforms with the eligibility criteria for this rate. The contractor must confirm that your system has sufficient capacity to provide heat to the whole home when running on fuel and that it can automatically switch from electricity to another source of energy. You must sign the certificate to confirm that you want to pay rate DT and send the signed form to the address indicated. Note that you must pay for all related work: inspection of your dual-energy system, making it qualify for Rate DT, if necessary, and the installation of the indicator light, supplied free of charge by Hydro-Québec, which will tell you when the higher price applies.