Why is my car blowing out cold air when the heat is on?
by
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.
Here are the most common reasons why your car heater isn’t blowing hot air. Low coolant: Whether caused by a leak or water evaporation, low coolant is the most common source of poor heater output. Thermostat: A stuck-open thermostat prevents the engine (and coolant) from heating up.
If you think the cause for your car heating not working is related to the blower fuse, be sure to replace it with one of the same amperage. The fuse may have blown due to age, or it may suggest an underlying problem. If the replacement fuse (of the same amperage) does not blow, you may well have identified the problem.
What to check if heat is not working in car?
The first thing to do if you’re having issues with your car heater is to check your engine coolant. Make sure to do this when your engine has cooled down to avoid being burned. If your coolant level is too low, there won’t be enough hot liquid in the heater core, resulting in cold air.
Why is my car blowing out cold air when the heat is on? – Related Questions
How do you troubleshoot no heat?
Heater Not Working?7 Troubleshooting Tips:
Check that your thermostat is set to “heat.”
Change the filter.
Make sure the gas is on.
Clear the chimney exhaust flue.
Clean away leaves and debris from exhaust vents.
Flush out the drain lines.
Check for blocked ducts restricting airflow.
How do you know if your car heater core is clogged?
A noticeable difference in airflow could indicate that the heater core fins have been clogged and are restricting airflow.
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.
What are two signs that the heater core has failed?
First, the heater core could be malfunctioning and, as such, the defrosters aren’t working. Second, the core could be blowing fog/smoke into your vehicle’s cabin. Both are bad signs and need to be checked into right away.
How do I unclog my heater core without removing it?
To clean the blockage, you need to flush water or air through the heater core. By doing so, the grime and dirt that’s causing the clog will come out through the inlet hose. Now, insert a water hose into the outlet hose. If you have access to an air compressor, you can use that to push out the coolant and grime.
Does a radiator flush clean the heater core?
After they will drain the system once more. Then they will wash out the area near the water pump, where there are a lot of little seals that, if cracked, can cause leaks and add even more debris to your cooling system. After another drain, your mechanic will wash out the heater core.
How do you unclog a car’s heater core?
Will flushing a heater core fix it?
A clogged heater core will prevent the coolant from passing through it, limiting the amount of heat that can be transferred. Flushing the heater core can remove these clogs, but if it fails to work, you may need to have your heater core replaced.
What does a clogged heater core sound like?
It makes a noticeable gurgling sound under the dash as the coolant flows past the air pocket in the heater core. The heater core is unable to heat the cabin properly. Air pockets in the coolant system contaminate the coolant and damage aluminum parts.
What happens if you don’t bleed air out of cooling system?
Over time, air can become trapped within your radiators, leading to cold spots and a less-than-optimal performance from your home heating devices.
How do I know if I have air in my coolant system?
Signs and symptoms of radiator airlock include:
Overheating during normal driving.
Heater not functioning correctly.
Reduced performance.
Radiator leakage / losing coolant quickly.
How do you burp a heater?
How long does it take to bleed air out of cooling system?
FAQs. How long does it take to bleed air out of the cooling system? Usually, it takes about 15-30 minutes, depending on the model and method you follow. It, however, takes 15-20 minutes to heat the engine and get rid of the coolant.
What does burping a car mean?
Burping (so named because of the noise made by the bubbles of coolant exiting the radiator filler neck) is done with the radiator cap removed on cars without a valve. You wait for the car to warm up so the thermostat opens, and then the pressure of the expanding coolant being heated drives the air out.
How do you manually burp?
Get air into your throat by sucking in air through your mouth until you feel an air bubble in your throat, and then block the front of your mouth with your tongue so you can release the air slowly. This should trigger a burp.