Programmable Thermostat

This replacement thermostat is compatible with the Resideo TH1100DH1004/U and delivers reliable temperature control for heat-only HVAC systems in residential and light commercial applications. The non-programmable design provides straightforward operation ideal for facilities requiring simple, dependable heating management without complex scheduling features. The unit features a digital backlit display that illuminates via convenient up/down buttons, showing current temperature readings and displaying "Heat On" status during operation. Temperature adjustment is precise to 1 Degrees F increments, with selectable operating ranges including standard mode (40-90 Degrees F) and garage mode (35-90 Degrees F) to accommodate various installation environments. This thermostat is engineered for versatile system compatibility, functioning with gas, oil, electric, millivolt (750 mV), and 24V heating systems. Its simple slide switch offers Heat or Off positions, eliminating unnecessary controls for heat-only applications. The unit supports dual power options, operating via three included AAA batteries for portable or temporary installations, or hardwired connection at 24VAC for permanent system integration. Designed in a horizontal mounting orientation, this replacement thermostat provides an economical solution for maintenance, replacement, or retrofit projects where Resideo/Honeywell Home PRO 1000 units are specified. The durable construction and straightforward interface make it suitable for warehouses, basements, utility spaces, and other settings where reliable heat-only temperature regulation is required without advanced programming capabilities.