Final answer:
Routine maintenance for a thermostat generally includes replacing the batteries. Other home maintenance tasks involve changing filters to prevent dust and pollutants from circulating. Professional assistance is needed for tasks such as lubricating fan motors or adjusting refrigerant levels.
Step-by-step explanation:
Routine maintenance for a thermostat controlling residential heating and cooling can involve several tasks, but from the options provided, the correct answer is b. Replacing the thermostat batteries.
It is essential to ensure that your thermostat is always functioning correctly as it regulates the temperature in your home. In addition to replacing batteries, other routines include changing filters regularly on your central heater and air conditioner, as these filters trap dust and other pollutants.
Although not directly related to thermostats, turning the thermostat down can save energy, as the heating system must work harder to replace the heat lost when there's a large temperature difference between the inside and outside. It is not typical for a homeowner to lubricate the fan motor or adjust refrigerant levels as these tasks are usually performed by a professional.