how to turn on heater in car

How To Turn On Heater In Car

As the weather turns cold, having a working heater in your car becomes essential for a comfortable driving experience. Sitting in a freezing vehicle trying to defrost the windows is an unpleasant way to start your morning commute.

This comprehensive guide will walk you through everything you need to know about turning on your car’s heater. We’ll cover the basic controls like temperature and fan speed, how to troubleshoot common issues, and maintenance tips to keep your heater running optimally all winter long.

Whether you drive an older model with manual dials or a newer vehicle with digital climate controls, the fundamentals are the same. Read on for a detailed look at how to operate your car’s heating system for toasty warm comfort on the road.

How Car Heating Systems Work

Before jumping into the specifics of adjusting your heater controls, it helps to understand how the system operates. Here’s a quick overview of how your car creates and circulates warm air: The cooling system circulates hot coolant from the engine through a heating core.

This core contains numerous small tubes and fins that allow the hot coolant to transfer its heat to the air. An electric blower motor pulls in cold outside air and forces it across the heating core. As the air passes through the core, it absorbs heat from the hot coolant.

The heated air then travels through a series of ducts and vents that direct it into the passenger compartment. The temperature of the air can be adjusted by controlling the blend of heated and unheated air. A thermostat senses the coolant temperature and controls the flow through the core to prevent overheating.

How Car Heating Systems Work
How Car Heating Systems Work

Turning on the Heater – Manual Controls

If your vehicle has a traditional heater setup with manual dials and controls, here are the basic steps to get warm air flowing:

  • Start the engine – Give your engine a couple minutes to warm up to operating temperature. Cold engines won’t produce enough heat.
  • Adjust temperature dial – Turn the dial clockwise toward the red section for hot and counterclockwise toward blue for cooler air. Set fan speed – Rotate fan control knob to the right to increase fan speed. Higher fan speed circulates air faster.
  • Direct vents – Adjust vent direction and open/close dash vents to direct airflow. Pointing vents at your feet helps warm quicker. Set airflow – Use the mode selector to choose airflow to feet, dashboard, windshield, or a mix.
  • Use recirculation if needed – The recirculation button circulates cabin air to heat faster. Don’t use it to defog windows. Turn on rear defroster if needed – Press the rear defogger button to clear fogged rear glass.

With manual systems, you’ll need to periodically adjust the settings as the cabin warms up. It’s normal to gradually taper down the heat and fan speed.

Turning On The Heat - Manual Controls
Turning on the Heat – Manual Controls

Operating Automatic Climate Control

If you have a newer vehicle equipped with automatic climate control, the process of heating the interior is even simpler. Here’s how to use auto climate control:

  • Press AUTO – The auto button activates the system to maintain your set temperature automatically.
  • Set desired temp – Use the up and down buttons to set your preferred cabin temperature.
  • Adjust fan speed if needed – You can manually increase fan speed for faster heating.
  • Point dash vents – Direct the dash vents toward you for enhanced comfort.
  • Use windshield defroster as needed – Press the defrost button to clear fog and ice from the windshield.

With automatic climate control, the system does the work of adjusting heat output and fan speed to maintain your set temp. Just set it and forget it!

Positioning Vents for Optimal Heating

Getting the vent position right makes a big difference in effectively heating the cabin. Here are some tips:

Point dash vents toward your upper body to warm your core. Direct floor vents at feet to keep toes from freezing. Angle center vents up slightly to circulate air without blowing directly on you. Adjust side window vents to prevent fogging and icing on the glass.

  • Keep the middle vent clear to maintain airflow to the back seat.

Take a moment to optimize the vent positions. Your passengers will appreciate the cozy warmth too.

Positioning Vents For Optimal Heating
Positioning Vents for Optimal Heating

Setting the Right Temperature

When using automatic climate control, choosing the right temperature setting makes all the difference. Here are some tips:

  • Start around 72°F and adjust as needed. You can fine-tune by 1-2° at a time.
  • Lower setting for warmer days, higher for colder days.
  • Heat only to a comfortable level to save fuel. Max heat uses more fuel.
  • Front and rear seats may require different temps for comfort.
  • Allow time for cabin to reach set temp before adjusting further.

Think about layers too. You may be comfortable at a lower cabin temp if wearing a sweater or jacket.

Tips for Faster Heating

Getting warm air flowing quickly makes cold weather driving much more pleasant. Here are some tips to heat up faster:

Start engine and turn on heat before driving. Sitting for 5-10 minutes allows the engine to warm up. Remove snow, ice from hood and undercarriage. This allows better airflow and heat transfer.

  • Switch to recirculation mode initially to reuse warmer cabin air.
  • Place sunshade in windshield to reduce cold radiating in.
  • Use seat warmers and heated steering wheel if equipped.
  • Wear warm layers like gloves and hats until cabin warms.

With a little preparation, you can walk out to a toasty interior and be on your way in cold weather.

Tips For Faster Heating
Tips for Faster Heating

Defrosting the Windshield

One of the key functions of the heating system is defogging and defrosting the windshield. Here are some tips for clearing fogged or icy windows fast:

Use defrost mode directing air flow to windshield. Turn temperature dial to highest heat setting. Engage air conditioning for dehumidifying if equipped. Increase fan speed to highest setting. Angle side window vents toward the glass.

  • Use rear window defogger if equipped.
  • Warm engine helps too so let it idle a few minutes.

Being able to see clearly is absolutely vital for safe winter driving. Keep these windshield defrosting tips handy until springtime.

Recirculate vs. Fresh Air Mode

Many heaters have a recirculate option that discontinues drawing in fresh outside air. This setting can be advantageous in some conditions but disadvantageous in others:

Advantages of recirculation mode:

  • Heats cabin air faster as doesn’t add cold outside air.
  • Can block out foul exhaust or other outside odors/fumes.
  • Cuts airflow through system on very dusty roads.

Disadvantages of recirculation mode:

  • Air can become stale without fresh air intake.
  • Windows fog more easily without drier outside air.
  • Doesn’t clear windshield as fast as using fresh air.

Use your discretion toggling between regular and recirculated air flow depending on conditions.

Recirculate Vs. Fresh Air Mode
Recirculate vs. Fresh Air Mode

Heating Tips for Hybrid/Electric Vehicles

Hybrid and electric vehicles heat the cabin a little differently than gas engines. Here are some key tips:

Limited engine heat so rely more on electric resistance heaters. Preheat while plugged in to conserve battery for driving range. Avoid prolonged idling. Doesn’t help warm electric vehicles.

Use seat and steering wheel warmers to supplement. Keep an eye on cabin preconditioning settings for optimal heating. Focus vents on occupants not glass to retain heat better.

Though electric vehicles don’t generate waste engine heat, their cabin heating can still keep pace with conventional cars using these strategies.

Adjusting Rear Heat and Controls

Don’t forget about keeping rear seat passengers comfortable too. Here are some tips:

Sync front and rear climate zones if equipped. Set same temperature for both. Adjust rear vents to point up slightly and towards passengers. Clear objects blocking rear floor vents and under seat ducts.

  • Check rear intake grilles behind rear wheels are not blocked.
  • Use child safety lock if kids are messing with settings.
  • Rear and front heated seats can be controlled independently.

Taking a moment to optimize the rear heat will pay dividends in passenger comfort.

Adjusting Rear Heat and Controls

Common Heating System Problems

While car heating systems are generally quite reliable, problems can occur. Here are some of the most common heating issues:

Lack of heat:

  • Low coolant level
  • Air trapped in system
  • Failed thermostat
  • Heater core leak/clog
  • Water pump failure
  • Blower motor failure


How do you run heat in a car?

Most cars use the engine’s coolant system to provide heat inside the cabin. As the engine runs, it heats up the coolant. The hot coolant then circulates through a heater core, which uses a fan to blow air across the hot core and into the cabin. This warms up the interior of the car.

Do you turn AC on for heater in car?

No, you do not need to turn on the AC to get heat in a car. The AC or air conditioning cools and dehumidifies the air, while the heater uses hot coolant from the engine to warm up the air. They are separate systems. To get heat, you just turn the temperature dial or switch to heat without needing to activate the AC.

Where is the heater switch in a car?

The heater switch is usually located on the center console or dashboard. It allows you to control the temperature inside the cabin. Turning the switch clockwise raises the temperature and engages the heater. Turning it counterclockwise lowers the temperature. Many modern cars have digital controls instead of a physical dial or switch.

How do you turn on an engine heater?

Many cars have an engine block heater or oil pan heater as an option. These are used in very cold climates to help start the engine. To use it, you plug the heater cord into a regular electrical outlet when the car is parked. This warms the engine coolant or oil so the engine can start easier in extreme cold. The heater turns on automatically when plugged in and doesn’t have a separate switch.


In summary, there are a few simple steps to turn on the heater in most cars. First, start the engine to allow the coolant to circulate and warm up. Next, locate the temperature control dial or buttons, which are usually on the center console or dashboard.

Turn the dial or press the button to raise the temperature setting from cold to hot. Many cars have a red side for hot and a blue side for cold. The heater blows air across the hot heater core and into the cabin to provide heat.

Monitor the temperature gauge to see the engine warming up. Finally, adjust the fan speed and temperature setting as needed for comfort. Following these basic steps will allow you to efficiently turn on and control the heater in your car.

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