The honest starting point in Arizona: there is no utility rebate for repairing or replacing a gas furnace. Most Arizona homes heat with heat pumps, Southwest Gas dropped its furnace rebate for the 2026 program year, and the electric utilities have never rebated gas furnaces. For a furnace household, the real, available lever is the smart thermostat — and for APS customers that is Cool Rewards.
Cool Rewards pays a $50 credit to enroll an eligible Wi-Fi thermostat in the demand-response program and $35 per year per thermostat to keep it enrolled, on top of a discount of up to $85 when you buy a qualifying thermostat through the APS marketplace. In exchange, APS can make brief temperature adjustments during summer peak-demand events between June 1 and September 30, which you can override at the thermostat.
One change to note: APS's older standalone thermostat-purchase rebate ended December 31, 2025 under an Arizona Corporation Commission decision, so the marketplace discount plus the Cool Rewards enrollment credit are now the path, not a separate mail-in rebate. Because a smart thermostat manages heating as well as cooling, the device still earns its keep through the furnace season even though the utility's events are summer-only.
Enrolling is low-effort: buy or already own a supported Wi-Fi thermostat — ecobee, Google Nest, and Honeywell Home models are generally eligible — and opt in through the APS marketplace or your account. During a summer event APS adjusts your setpoint briefly, and you can override it; through the heating season the thermostat simply runs your furnace on an efficient schedule with no events at all.
Territory is the catch in metro Phoenix: APS and SRP divide the valley street by street, and the two programs are not interchangeable. Check which utility bills your electricity before enrolling. If you are actually facing a furnace replacement rather than a thermostat upgrade, the Arizona reality is that you'll fund that yourself — so weigh the repair-vs-replace decision on the equipment's age and a combustion-analysis safety check, not on a rebate that doesn't exist.