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.
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.
A faulty or broken thermostat is the most common cause of your car’s failing heat. Stuck open or stuck closed, the part can not only cause issues with your heat but also your engine’s cooling system. One becomes an issue of comfort, the other becomes an issue of “Oh no, I’ve borked my engine.”
What could cause a heater to not provide heated air?
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.
Why is my car blowing out cold air when the heat is on? – Related Questions
What to check if heat is not working?
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 fix your heater when it’s blowing out 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.
What is the most common part failure that causes no heat?
Low coolant: Whether caused by a leak or water evaporation, low coolant is the most common source of poor heater output.
How do I fix the air in my heating system?
Step 1: Turn off your central heating and wait for around 20 minutes for the system to cool down. Step 2: Lay a dry cloth or towel beneath the radiator you want to bleed, just in case any water escapes. Step 3: Use your radiator key to slowly open the valve, turning it anti-clockwise to do so.
The lukewarm air appearing in your heater can be the outcome of a leaky duct. If your air ducts are leaking, cool outside air is making its way into your ductwork. This can cause the air to really feel only lukewarm. The repair: Duct sealing.
Why does my heat not feel hot?
It’s most likely an incorrect thermostat setting if you find your furnace blowing warm air, not hot. The fan is set to “on” instead of “auto.” Furnaces only pump hot air until the thermostat setting is reached, so if your fan is always on, it will blow both hot air when the furnace is heating and cold when it’s not.
Why is my car heater only lukewarm?
Your thermostat may be stuck, which can prevent the heater system from warming up sufficiently. If your heater is blowing lukewarm air rather than cold air, this may be the culprit. Air bubbles may be trapped inside of the cooling system, which can cause malfunction. This air must be flushed out by a professional.
How do I know if my furnace vent is clogged?
Look for signs of blockages by examining the pipe itself – water streaks or rust on the flue pipe may indicate a blockage, causing moisture to back up. Soot near the furnace is another sign of a flue blockage.
How do you unclog a heater vent?
Here’s What To Do
Turn off the power connected to the heating and air conditioning system.
Unscrew the air duct covers or grilles from the walls. Use your brush to clean the grates thoroughly.
Vacuum the ducts as much as possible. Consider renting a heavy duty vacuum for this purpose.
Have an assistant flush a toilet while you hold your hand over the vent.
Use a plumber’s snake of electricians fish tape to unclog the stoppage.
If you can’t entirely remove the clog with your “snake,” use a garden hose to flush out remaining debris.
How do you clear a blocked vent?
What happens when vents are blocked?
Proper Airflow is Important
This constant push of air to a blocked air vent can create an increase in pressure, and when combined with inadequate airflow, it can cause damage to your HVAC system’s heat exchanger. This damage can also lead to the exhalation of carbon monoxide and result in leaking ductwork.
How do you clean air vents without removing them?
Vacuum the vents to remove most of the dust and dirt. Take a damp microfiber cloth to wipe the outside of the vent, as well as the wall and ceiling around it. Do not use water or cleaning chemicals, as these will smear the dirt around and make it more difficult to remove buildup!
Where are drain vents located?
But there’s another part of your plumbing system that can become blocked: your sewer vents. Located on the roof, these vent pipes allow gases to escape from your sewer system. They regulate the air pressure in your system, allowing waste to flow freely.
What causes a clogged vent pipe?
The plumbing vent allows air into the system to overcome the vacuum and force the water through the pipes. It also allows any sewer gases left behind in the pipes to flow out of the building. This vent pipe is usually located on the roof, which means it can easily become clogged with dirt and debris.
What happens if drain isn’t vented?
This could lead to problems such as overflowing drains, backed-up toilets, and similar plumbing issues. Correcting the problem may be as simple as removing a clog in the drain line, but it could also require more substantial work to find and fix drain lines.