QA

Quick Answer: What Would Cause A Car Heater To Blow Cold Air

Low Coolant Level The coolant (usually a mixture of water and antifreeze) in your engine doesn’t just work to keep the engine from overheating: It’s also the source of heat supporting the heating system. If there isn’t enough coolant in your system, the heater core will blow cold air into your car.

What do I do if my heater is blowing cold air?

How To Troubleshoot Furnace Blowing Cold Air Step 1: Check Thermostat Setting. First and most importantly, make sure your thermostat is set to Heating Mode. Step 2: Evaluate and Adjust Your Vents: Step 3: Assess Furnace Filters and Replace Filters If They Are Dirty. Step 4: Call An HVAC Pro.

Why is my heat not blowing hot air in my car?

The heater core looks (and works) similar to your car’s radiator — it’s made up of a series of narrow tubes and fins. Faulty heater cores and low or contaminated coolant levels often come hand in hand, and both issues may lead to your engine overheating and your heater not blowing hot air.

When my car is idling the heater blows cold air?

The heater’s radiator clogs over time making it harder for the coolant to pass through its bearings, leading to slightly warm air or completely cold air blown at idle. You can try cleaning the radiator and check if a crack has not been created where the liquid can come out or air can enter.

Why is cold air coming out of my vents when heat is off?

This issue could be caused by an improper thermostat setting. Check that the fan blower switch is set to “auto” and not “on.” When the “auto” setting is chosen, the fan will only run during a heating cycle and won’t push air that feels cooler through the vents in between cycles.

How do I know if my heater core is clogged?

Heater core failure symptoms Weak or no airflow. Cold air (not warm) coming through the vents when the heater is on. Coolant leakage visible inside the cabin or a damp smell.

How do I know if my thermostat or water pump is bad?

You should be able to turn on your heating or cooling system from the thermostat, or change operation back and forth from heating to cooling. If you make changes at the thermostat and get no response whatsoever from your furnace, air conditioner, or heat pump, it could mean the thermostat is bad.

How do you know if your thermostat is bad in your car?

One of the first things you will notice is the temperature gauge is higher than normal. It may even start to fluctuate frequently. If you notice the gauge is hovering ¾ of the way from the top, then your thermostat is experiencing damage in the form of overheating. This can soon lead to your engine and car overheating.

Can a blown fuse cause heater not to work?

Faulty Wiring or Blown Fuses Similar to your broken HVAC controls, your car’s wiring could be broken or have a short in it. This would mean the heater isn’t triggered when the driver commands it to function.

How do I unclog my car vents?

Method 1 – Using a Cleaning Solution and a Foam Brush Step 1: Clean the Vent Slats With a Foam Paintbrush Dabbed in the Solution. Step 2: Wipe the AC Vents Dry With a Dry Foam Paintbrush or Towel. Step 3: Wash the Used Foam Paintbrushes and Let Them Dry.

How much does it cost to replace a blower motor in a car?

“A new car blower motor costs about $50 to $100 for the part and $80 to $100 in labor. Add it up and you’re looking at a total charge of $130 to $200 for a new car blower motor.

Can a heater core unclog itself?

Heater cores don’t normally clog up on their own. It’s usually caused by an outside force. If you run straight water in your cooling system or your cooling system is full of scale and rust, your heater core can clog up. While the engine is cool, remove the radiator cap and inspect the coolant.

Why does my heater get hot then cold?

This problem could be either an engine thermostat that is not keeping the engine at a constant running temperature (temp gauge steady in the center), or the heater control valve or controls are malfunctioning not allowing engine coolant into the heater core (passenger compartment).

How do I test my car thermostat?

Start your car’s engine and allow it to idle. Look through the radiator filler neck to see if the coolant flows. At this time, it should not be flowing as your car has not reached the operating temperature to cause the thermostat to open. If you find the coolant is flowing, it means the thermostat valve is open.

How do I know if my water pump is bad in my car?

5 Symptoms of a Failing Water Pump Coolant Leaking. One of the first signs of a potentially faulty water pump is a puddle of coolant on the ground where you’ve parked your car. Rust or Deposit Build-Up. Noise. Overheating. Steam.

How do I know if I need a new thermostat in my car?

If you notice any of these telltale signs, your car may need a new thermostat: The temperature gauge says the engine is very hot or cold. The engine tends to overheat. The temperature in your car often changes drastically. You have coolant leaking under the car.

What fuse controls the heat in a car?

Locate the blower motor fuse, likely a 30 or 40 amp, it may be marked on the fuse box cover or in the driver’s manual. Use a test light or voltmeter to check for power at the blower motor fuse with ignition and blower motor on.