The Honeywell Round Connected Modulation Thermostat Y87C2004 is a wired smart thermostat designed for precise temperature control in residential heating systems. This model features advanced modulation technology that continuously adjusts the boiler output to maintain consistent room temperatures and eliminate temperature fluctuations, thereby improving energy efficiency. The device supports remote control and programming via smartphone apps and voice assistants through Wi-Fi connectivity. With its classic round design of approximately 85 mm in diameter and 30 mm in depth, it fits various decor styles and offers a clear digital temperature display. The thermostat provides multiple operating modes, including manual control, programmable schedules, and vacation modes for flexible temperature management. It is compatible with most modern central heating systems and supports the OpenTherm protocol for optimal boiler communication. Installation requires professional setup with a standard two-wire connection, and the device operates within a temperature range of 5 °C to 30 °C with adjustment steps of 0.5 °C. The thermostat includes features such as frost protection, open window detection, and adaptive learning capability that optimizes heating patterns based on usage behavior. Constructed with durable materials and intuitive controls, this Honeywell thermostat delivers reliable performance for year-round comfort management and helps reduce energy consumption through intelligent temperature regulation.