Even the most advanced HVAC system can't overcome poor thermostat habits. These common mistakes cost Bay Area homeowners hundreds of dollars annually.
Mistake 1: Constant Temperature Adjustments
The Problem:
Frequently adjusting the thermostat up and down wastes energy and stresses your system.
Why It's Wasteful:
Systems work most efficiently at steady settings
Constant changes cause more on/off cycling
Temperature swings create comfort issues
The Fix:
Set it and forget it (mostly)
Use programmable schedules
Adjust by 2-3 degrees max for comfort tweaks
Mistake 2: Setting Extreme Temperatures to Heat/Cool Faster
The Problem:
Setting the thermostat to 60°F in summer or 85°F in winter thinking it will reach your desired temperature faster.
Why It Doesn't Work:
HVAC systems deliver air at the same temperature regardless of thermostat setting
You're just asking the system to overshoot your comfort zone
Results in temperature overshooting and wasted energy
The Fix:
Set to your actual desired temperature
Be patient—systems work at consistent rates
Consider a larger system if heating/cooling takes too long
Mistake 3: Leaving the Same Temperature 24/7
The Problem:
Maintaining the same temperature when you're asleep or away from home.
The Waste:
Cooling/heating an empty house
Missing 10-20% potential savings
System runs unnecessarily
The Fix:
Raise cooling setpoint 7-10°F when away
Lower heating setpoint 10-15°F when away
Use programmable schedules for automatic adjustments
Consider smart thermostats with geofencing
Mistake 4: Blocking the Thermostat
The Problem:
Furniture, curtains, or other objects near the thermostat affect its temperature readings.
The Result:
Thermostat reads incorrect temperature
System runs too long or short-cycles
Rooms never reach comfortable temperature
The Fix:
Keep 4+ feet clearance around thermostat
Remove nearby heat sources (lamps, electronics)
Ensure thermostat isn't in direct sunlight
Consider relocating if position is problematic
Mistake 5: Wrong Fan Setting
The Problem:
Leaving the fan set to "ON" instead of "AUTO" year-round.
ON vs. AUTO:
ON: Fan runs continuously
AUTO: Fan runs only when heating/cooling
When "ON" Hurts:
Increases electricity use ($10-50/month)
Can increase humidity in summer
Wears out fan motor faster
When "ON" Helps:
Improves air filtration
Evens out temperatures between rooms
Useful during wildfire smoke events
The Fix:
Use "AUTO" as default, switch to "ON" for specific purposes.
Mistake 6: Ignoring Maintenance Reminders
The Problem:
Dismissing or ignoring filter change and maintenance reminders.
The Cost:
Dirty filters reduce efficiency 5-15%
System works harder, wearing out faster
Indoor air quality suffers
The Fix:
Set phone reminders for monthly filter checks
Change filters when dirty (usually 1-3 months)
Schedule annual professional maintenance
Mistake 7: Incorrect Programming
The Problem:
Programmable thermostats set incorrectly or not programmed at all.
Common Errors:
Wrong time/day settings
Schedule doesn't match actual patterns
Forgetting to update after schedule changes
The Fix:
Review and update programming quarterly
Use smart thermostats that learn automatically
Keep instructions handy for adjustments
Mistake 8: Closing Vents in Unused Rooms
The Problem:
Closing multiple supply vents to "redirect" air to other rooms.
Why It Backfires:
Creates pressure imbalances
Can damage ductwork
Reduces system efficiency
May cause comfort problems elsewhere
The Fix:
Keep most vents open
Close no more than 20% of vents
Consider zoning for true room-by-room control
Mistake 9: Poor Thermostat Placement
The Problem:
Thermostats installed in bad locations give inaccurate readings.
Problem Locations:
Near exterior doors or windows
In direct sunlight
Near kitchen or bathroom
On exterior walls
Near supply vents
The Fix:
Relocate to interior wall
Choose central location
Avoid heat-generating areas
Professional relocation costs $100-300
Calculating Your Losses
Estimate your annual thermostat-related waste:
Constant adjustments: $50-100/year
No setback programming: $100-200/year
Wrong fan setting: $100-150/year
Poor maintenance: $50-150/year
Total potential savings: $300-600/year
Simple habit changes and proper thermostat use can significantly reduce your energy bills without sacrificing comfort.