This is a smart thermostat used daily as the control point for HVAC comfort and energy savings. Because it's wall-mounted and powered continuously, failures are often tied to power/voltage issues, sensor drift, or Wi-Fi module problems.
Repair is usually worthwhile if the issue is wiring, a power adapter/module, or configuration-many "failures" are actually HVAC control wiring problems. If the thermostat hardware itself has a failing touch interface, persistent reboot loops, or Wi-Fi instability that persists after resets, replacement is typically more economical than repair.
Use the threshold as a firm cap unless the thermostat is very new and under warranty. A key tipping factor is comfort risk: if you're losing heat/AC control intermittently, the cost of downtime can exceed a modest replacement price.
Also consider software support and ecosystem fit; newer models may bring better sensors and automation that improve real-world value even if the old unit still partly functions.