My Watchdog 15 is showing a higher temperature than what my thermostat is showing.

In still air environments the onboard sensor is susceptible higher temperature readings due to circuit board heating. With that, air temperatures in a room are rarely, if ever, uniform throughout the space, due to convection currents, relative proximity to sources of heat and cold air, and other thermal effects. Our Watchdog products have an internal temperature offset that you can adjust to compensate for board heating. This is found by selecting the Configuration Wrench in Sensors-Overview.