Nissan Altima Heater Operation


In the Heating mode, press the OFF position button to activate normal heating. Adjust the air flow control and fan speed, and set the temperature between the middle and hot positions.


For Ventilation, press the OFF position button, adjust the air flow control, fan speed, and temperature control to direct outside air to side and center vents.

Defrosting or Defogging

To clear windows, use the Defrosting or Defogging mode by pressing the defrost/defog button. Adjust the fan control and temperature dial as needed.

Bi-level Heating

Activate Bi-level Heating by pressing the OFF position button, adjusting air flow, fan speed, and temperature control for warmed air to side, center vents, and front/rear floor outlets.

Heating and Defogging

In Heating and Defogging mode, press the air flow control button, adjust fan speed and temperature to heat the interior and defog the windshield.

Operating Tips

Clear snow and ice from wiper blades and the air inlet for optimal Heater Operation.


  • Fan Control Dial: Turns the fan on/off and controls speed.
  • Air Flow Control Buttons: Select air flow outlets.

Common Issues: Why Does My Nissan Altima Heater Act Up?

Idle Heat Loss

If the heater loses heat at idle, several factors may contribute to the issue.

Alternator Strength

Check the alternator’s strength; a weak alternator may result in lower voltage at idle, impacting the heater fan’s performance.

Coolant Level and Quality

Ensure an adequate coolant level when cold and top up if necessary. Check for leaks, coolant age, and radiator condition.

System Blockages

Inspect for a clogged heater core, radiator, or faulty thermostat, as these can impede coolant flow and heat transfer.

Driving-Related Heater Issues

When the car’s heat only works while driving, consider the following possibilities.

Coolant Level

Verify the coolant level; low coolant might cause the heater to function only when driving due to higher water pump speeds.

Heater Hose Condition

Check for blocked or kinked heater hoses, which may collapse when soft and old.

Ducts and Diversion Issues

Inspect ducts for potential blockages or issues with the vacuum-controlled diversion system that may affect air distribution.

Electrical Factors

For potential electrical problems affecting the heater:

Blower Fan

A failing heater blower fan or charging system issues can result in insufficient voltage to spin the fan at idle.

Overall Recommendations

Regularly check coolant levels, inspect hoses, and address potential electrical issues to maintain optimal heater performance in your Nissan Altima.

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