Why would my car overheat but the heater blows cold air?
If your car is overheating but you are only getting cold air from the heater then this could be a sign of a blockage in the engine cooling system. If the coolant flow is restricted, this will cause the engine to run hot or overheat. This can lead to the engine over heating and no coolant getting to the heater core.
Why is cold air blowing when the heat is on?
Your furnace may be blowing cold air because the filter is too dirty. A dirty air filter blocks airflow over the furnace’s heat exchanger, causing it to overheat. When overheating, your furnace can trip a high limit switch, causing the furnace burners to shut off so that the heat exchanger does not crack.
Why is my car heater not blowing hot air?
Faulty Heater Core 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.
What temperature should the hot air be coming out of the vent?
14 to 20 degrees
The air coming out should be 14 to 20 degrees cooler than the air flowing in. Move the thermometer to a vent in each room or area of your home. If any of the vents are much colder or warmer than another, there may be a problem with the ductwork, or the distance may be too great from the blower.
How can you tell if your thermostat is open?
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 you know if your thermostat is stuck open?
Symptoms of a bad thermostat Thermostat stuck open: When the thermostat is stuck open, the engine temperature drops below normal when driving, especially on the highway in cold weather. A stuck-open thermostat can also cause lack of heat from the heating system. The Check Engine light may come on too.
Will a radiator flush unclog heater core?
The heater core is similar to a radiator and is a part of the vehicle’s coolant system. Flushing the heater core can remove these clogs, but if it fails to work, you may need to have your heater core replaced.
What causes a heater to blow cold air?
The following are some issues that may be causing the heater to blow cold air: Low coolant levels. A plugged/clogged heater core. A faulty thermostat (thermostat that is stuck) Broken blower and/or blower motor. Heater core bypass hoses that have leaks.
Why does my car keep blowing cold air?
If your car is blowing cold air that means that, the hot coolant is not reaching the heater core. This is likely the fault of your engine thermostat. As they age like everything, they wear out. The engine thermostat remember, is supposed to open but old engine thermostats often get stuck.
What to do if your air conditioner is blowing cold air?
A faulty thermostat can also make your temperature gauge read lower than normal and turn your check engine light on. Solution: Your mechanic can test the thermostat and replace it if necessary. You may be able to remove the thermostat yourself and test it by boiling it in water and seeing if it closes.
How to diagnose blows cold one side, hot on other side?
So your first step in diagnosing a blows cold one side, hot on other side condition is to operate each temperature control to see which side changes temperature. The actuator that changes temperature is good, the actuator that doesn’t is bad. This test also proves out the HVAC controller.