We've all been there—it's a freezing Northeastern winter morning in the NY/NJ/CT tri-state area, and the journey from your door to your car feels like a hike across the Siberian tundra. You jump in your vehicle, turn the ignition, begin driving, and wait for the warm air to start pouring from your heater.
Only... it never comes. In fact, the air is ice cold!
There are many reasons why your car's heater may be blowing cold air, and while you can solve some car problems with basic DIY, others may require the assistance of a qualified automotive technician.
Why Is My Car Heater Only Blowing Cold Air?
To understand how to fix and prevent heater issues in your car, it's best to learn a bit about its inner workings.
Put simply, the coolant in your engine that prevents your engine from overheating is what heats your cabin. Here is how it works in a few simple steps:
- Coolant is pumped through your engine and absorbs the excess heat, then moves into your radiator, where it cools down before moving back through your engine to absorb more heat, and so on.
- The engine thermostat controls the temperature of the coolant that runs through your engine.
- Some heated coolant takes a detour from your engine and moves into the heater core, which is basically a small radiator.
- When your car heater is turned on, the blower fan sends air across the heater core transferring heat from the coolant into the cabin. Sometimes vehicles also have a heater control valve that controls coolant flow into the heater core.
- The coolant then leaves the heater core and returns to the engine, where the cycle begins again.
So what would cause the airflow through your vents to be cold? Various issues may be at play, but here are the most common reasons your heater is only blowing cold air.
Reasons Your Car Heater Is Only Blowing Cold Air
1. Your Coolant Is Low
If there isn't enough coolant running through the heater unit, it'll struggle to heat up your air. When your car's engine is cold, the coolant level in your car's radiator needs to be checked. If it needs a top-up, do so and then run your engine for a couple of minutes to circulate the coolant.
2. You Have Water Leaks
There are various components in your car that can be prone to leaking. If there's a leak, you'll usually notice a wet spot underneath your car—this is important because any water from the leak could freeze overnight and leave you with no heat in the morning!
3. The Blower Fan Is Not Operating Properly
The fan inside your car's heater box controls airflow through your vents. If this is not operating correctly, it may be the reason why you're experiencing cold air blasts instead of warm ones.
4. Your Thermostat Is Stuck or Broken
If the thermostat in your car's engine is stuck, it won't open to allow hot coolant or steam into the heater.
If your thermostat is broken, the hot coolant will remain in your engine and never circulate through the heating system, causing you to experience cold air blowing from your vents.
5. You Have a Climate Control Problem
Do you have a problem changing between the hot and cold settings on your car's heater? If so, check for blocked air vents or broken controls. Sometimes, you can easily unblock blocked vents, but broken controls will require more extensive work to fix.
What Could Happen If I Don’t Fix My Car’s Heater?
Some car owners simply grin and bear it when it comes to heater issues. Unfortunately, it's never wise to simply ignore heater problems, as they could indicate a more significant problem.
For example, if your heater trouble is due to low coolant, this can create a host of other, more significant issues—from the engine overheating to a blown head gasket.
In this case, it's best to have a qualified auto technician carry out a full diagnostic check on your car as soon as possible. They'll diagnose what issues you may be having and recommend the best course of action.
Similarly, your car's heater helps with more than comfort—it also increases safety. The heater also helps reduce iced or foggy windows by heating the air inside the vehicle. If you can't warm your car, it'll be nearly impossible to defrost windows or prevent fog build-up. Having diminished visibility is a serious safety hazard while driving.
Should I Try to Fix My Car Heater Myself?
Plenty of online resources can help you identify car heater issues, but with so many potential causes, it's hard to say what the problem is. Even if you have a pretty good idea of the cause, you might not be able to fix it yourself.
Attempting to address car heater issues without the proper training and equipment can quickly lead to more serious problems. It's a good idea to consult a mechanic for some professional advice. They'll be able to troubleshoot your car heater problem with ease.
How Can I Avoid Car Heater Problems in the Future?
Fortunately, there are several practical steps you can take to prevent car heater issues in the future.
1. Have your car's heater system serviced annually by an auto technician.
2. Check the coolant levels in your car's radiator before you begin driving (do NOT check coolant levels if your engine is hot.).
3. Seek help when you notice any leaks or other engine issues—even the smallest problems can result in a broken heater or worse, so get help quickly!
The most important of all these steps is to get your car's heater system serviced every year. That way, you'll be able to head off any potential issues before winter.
Solve Your Car Heater Problems with a Trusted Technician
If your heater isn't blowing warm air, your driving experience can turn from cozy to frustratingly frigid in no time flat.
If you experience any of the problems discussed here, consult a mechanic as soon as possible. Otherwise, your car heater could stop working altogether, which will likely result in a larger headache and costly fix.
Working with your local AAMCO NY/NJ/CT auto technicians can help you diagnose and fix any issues with your car heater. Schedule an appointment today to learn how to address car heater problems—and many other issues—promptly.
Expect the Best
AAMCO has over 50 years of experience delivering total car care, from the transmission to tune-ups for more than 20 million vehicles. Customers depend on us for:
- Exceptional customer service
- The latest technology for diagnosis and repair
- Expert technicians who “fix it right the first time.”
- Best warranty coverage available
AAMCO Centers of the NY/NJ/CT Tri-State Area represent trust, quality, and value. If you’re having an issue with your vehicle, call us today!