The Texas summer can feel like it’ll never end, but by late September, cooler evenings and early mornings start to raise the question: when should you switch from AC to heat? With fluctuating temperatures between warm afternoons and chilly nights, many homeowners aren’t sure when it’s time to switch from AC to heating mode—or how to do it safely.
At Superior AC & Heat, we’ve seen what happens when heating systems are neglected until the last minute. Whether you’re a first-time homeowner or a seasoned pro, it pays to understand the ideal timing and steps for a smooth seasonal transition. Learn how to prepare with our fall HVAC maintenance guide.
Ideal temperature to switch on your heat
There’s no set calendar date to turn on the heat, but most HVAC professionals agree that once nighttime lows dip consistently into the low 60s or high 50s, it’s time to consider it. This typically happens in late September or early October for many areas in Texas.
If indoor temps drop below 68°F and you’re reaching for extra blankets, it’s a sign your comfort level is dipping. Instead of toughing it out, go ahead and warm things up. Waiting too long can stress your system with a cold start and make your home uncomfortable fast.
HVAC experts also suggest that when outdoor temperatures stay below 60°F or your home feels chilly despite extra layers, it’s time to switch.
How to prep your system before turning on the heat
Before switching from AC to heat, there are a few simple but important steps every Texas homeowner should take:
- Change your air filter – A fresh filter helps improve airflow and system efficiency during the switch.
- Adjust your thermostat settings – Set it to heating mode and choose a target temperature between 68–72°F. For more advice, visit our best thermostat setting blog post
- Test your system early – Turn the heat on for 15–20 minutes during a cool morning to make sure it runs smoothly.
- Listen for odd sounds – Banging, squealing, or grinding could signal a problem.
- Smell something burning? – A brief dusty smell is normal after months of AC use; it should go away quickly.
These steps help ensure your furnace or heat pump is ready before you actually need it, avoiding last-minute surprises.
Common problems if you wait too long
Delaying the switch from AC to heat can create a few issues:
- Burnout from cold starts: When a system hasn’t run for months and is fired up under stress, it can strain components.
- Unexpected breakdowns: Problems that went unnoticed during spring may surface when the system is fired up.
- Busy repair schedules: Once the first cold snap hits, HVAC companies get slammed with calls. Getting service may take days.
To prepare early, consider our furnace inspection checklist to ensure everything is in working order.
Energy-saving tips for fall heating
Once you do switch from AC to heat, a few smart habits can help keep energy costs under control:
- Keep thermostat at 68°F when home
- Lower it to 60–65°F at night or while away
- Use ceiling fans in reverse to distribute warm air
- Seal air leaks around windows and doors
- Keep curtains open during sunny hours for natural warmth
Heating costs in Texas can still add up—especially if your system isn’t running efficiently. Learn about ways to prevent those spikes in our HVAC efficiency blog.
When professional maintenance makes a difference
Getting a professional HVAC inspection in late September or early October is the best way to catch issues early. Here’s what Superior AC & Heat includes in our seasonal tune-ups:
- Checking and cleaning burners and heat exchangers
- Verifying carbon monoxide safety and ventilation
- Testing system startup and shutdown performance
- Inspecting and calibrating your thermostat
- Replacing dirty or clogged filters
For further help, find out why your air conditioner won’t turn on
Why this matters for Texas homes
Texas weather can be unpredictable. You might see 85°F during the day and 50°F by night. Your system needs to be flexible—and ready. A seamless transition helps avoid discomfort, higher bills, and emergency repairs.
Many Texans don’t think much about their furnace until it’s too late. But your HVAC works best when you plan ahead. Early fall is the ideal time to switch modes, test performance, and ensure your system is clean and calibrated.
Get help from Superior AC & Heat
When you’re ready to switch from AC to heat, Superior AC & Heat is here to help. Our expert technicians provide fast, affordable tune-ups, smart thermostat guidance, and full inspections to prepare your home for the colder season ahead.
Don’t wait for a cold front to catch your system off guard. Schedule your fall heating checkup today with our heating experts in Texas, and make sure your home stays warm, safe, and energy-efficient all season long.
Call Superior AC & Heat now—we’ll help you transition from AC to heat with confidence.
