{"product_id":"resideo-llc-rth21b-n-7-day-programmable-thermostat","title":"Resideo Llc RTH21B\/N 7 Day Programmable Thermostat","description":"\u003ch3\u003eProduct Description\u003c\/h3\u003e\n\u003cp\u003eThe RESIDEO LLC RTH21B\/N is a 7-day programmable thermostat built for residential heating and cooling systems. It supports 1 Heat \/ 1 Cool configurations and is compatible with forced air systems running gas, oil, or electric heat sources, as well as hot water heat and 750 mV millivolt systems. The thermostat offers multiple scheduling modes including 7-day, 5-1-1, 5-2, or 1-week programming, and scheduling can also be disabled entirely for manual operation. A large display with clear font makes daily use straightforward. Power is supplied by 2 AA batteries, not included. Licensed HVAC technicians and qualified installers handle residential thermostat replacements as part of standard system maintenance.\u003c\/p\u003e\n\u003cp\u003eThis thermostat is suited for residential applications where a simple, reliable programmable control is needed. It works with forced air systems using gas, oil, or electric heating, as well as hot water heat and 750 mV systems. It does not work with electric baseboard heat operating at 120 to 240 volts. The flexible scheduling options make it a practical fit for retrofit installations in single-stage residential HVAC systems where low-voltage thermostat wiring is already in place.\u003c\/p\u003e\n\u003ch4\u003eKey Features\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003eSupports 7-day, 5-1-1, 5-2, and 1-week programming schedules\u003c\/li\u003e\n  \u003cli\u003eCompatible with forced air (gas, oil, electric), hot water heat, and 750 mV millivolt systems\u003c\/li\u003e\n  \u003cli\u003e1 Heat \/ 1 Cool single-stage configuration\u003c\/li\u003e\n  \u003cli\u003eLarge display with clear font for easy reading and daily use\u003c\/li\u003e\n  \u003cli\u003eBattery-powered operation using 2 AA batteries (not included)\u003c\/li\u003e\n  \u003cli\u003eScheduling can be turned off for simple manual temperature control\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eCompatibility\u003c\/h4\u003e\n\u003cp\u003eCompatible with forced air systems using gas, oil, or electric heat sources, hot water heat systems, and 750 mV millivolt systems. Not compatible with electric baseboard heat operating at 120 to 240 volts. Designed as an OEM-style replacement for single-stage residential low-voltage thermostat applications.\u003c\/p\u003e\n\u003ch4\u003eInstallation Notes\u003c\/h4\u003e\n\u003cp\u003eInstallation should be performed by a licensed HVAC technician or qualified tradesperson in accordance with local mechanical codes. Always shut off power to the air handler or furnace control board before disconnecting the existing thermostat wiring. Confirm the system voltage is low-voltage (typically 24 volts) before installation, as this unit is not rated for line-voltage electric baseboard applications. Verify all wire connections are secure before restoring power and testing system operation.\u003c\/p\u003e\n\u003ch4\u003eTechnical Specifications\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSystem Configuration\u003c\/strong\u003e: 1 Heat \/ 1 Cool\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCompatible System Types\u003c\/strong\u003e: Forced air (gas, oil, electric), hot water heat, 750 mV millivolt\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eIncompatible System Types\u003c\/strong\u003e: Electric baseboard heat (120 to 240 volts)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eProgramming Options\u003c\/strong\u003e: 7-day, 5-1-1, 5-2, 1-week, or scheduling off\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePower Source\u003c\/strong\u003e: 2 AA batteries (not included)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePackage Quantity\u003c\/strong\u003e: 4 per package\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eWeight\u003c\/strong\u003e: 3.56 pounds\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eUnit of Measure\u003c\/strong\u003e: EA\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eStandard Information\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eBrand\u003c\/strong\u003e: RESIDEO LLC\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number\u003c\/strong\u003e: RTH21B\/N\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"RESIDEO","offers":[{"title":"Default Title","offer_id":51523986587954,"sku":"RTH21B\/N","price":250.96,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0270\/4519\/9983\/files\/c3636b71207374d07d451066ba0ae843.jpg?v=1785444644","url":"https:\/\/voomisupply.com\/products\/resideo-llc-rth21b-n-7-day-programmable-thermostat","provider":"Voomi Supply","version":"1.0","type":"link"}