Heat pump service calls often end with a request for phone control, and the PRO1 T721i handles that without a premium thermostat price. Sold here under the ALLTEMP listing, this T700-platform thermostat is Wi-Fi enabled with iOS and Android app scheduling, and runs 2-heat/1-cool heat pumps or 1-heat/1-cool conventional systems. HVAC contractors like the colour-coded terminals and universal subbase. Why HVAC techs pick it Heat pump (2H/1C) or conventional (1H/1C), including electric furnace and gas or oil heat. Wi-Fi scheduling from the app: 7-day, 5+1+1 or non-programmable. Dual fuel lockout, staging delay and emergency heat stage settings in tech setup. Separate heat and cool swing, room temperature calibration and selectable 5-minute compressor protection. 7 sq in display, glow-in-the-dark light button, 5-year warranty. Specifications Spec Detail Brand PRO1 IAQ (listed under ALLTEMP) Model T721i (T700 platform) Systems Heat pump 2H/1C or conventional 1H/1C; not millivolt Power 24 VAC hardwired, common wire required (18 to 30 VAC, Class 2) Wi-Fi 2.4 GHz, 802.11 b/g/n Control range 7°C to 32°C (44°F to 90°F) Load rating 1 A per terminal, 1.5 A total Swing Heat and cool each adjustable 0.2° to 2.0° Dimensions 4.7 x 4.3 x 0.9 in Warranty 5 years Pro tip from the counter The T721i won't run on batteries or power-stealing; it needs a 24 V common wire landed on the C terminal. Before selling it for a heat pump swap, open the old thermostat and check for a spare conductor in the cable, because a heat pump with auxiliary heat already needs O or B, Y, W2, G and R before the C wire is added. Best for: heat pump thermostat upgrades, dual fuel systems, rental and multi-unit HVAC service, contractors wanting app control on a budget Downloads: Installation manual (PDF) · Operation manual (PDF) We ship across Canada from Vaughan, ON. HVAC contractors can get trade pricing with a quote or at (905) 553-7171.