Q: Q: Heater only blows cold

asked by on

The blower works high and low but blows no heat, only cold air. It does say check coolant sensor but i dont know if that has to do with the heat blowing cold. If this is sonething simple, i can try to do it myself.

My car has 200000 miles.
My car has an automatic transmission.

Hi There, It sounds like your coolant temp sensor may not be transmitting the proper signal to the computer. The coolant temp sensor helps to control the temperature of the coolant by relaying this to the computer which then causes the cooling fans to come on at specific temperatures which then allow the coolant to cool down. The other possibility may be that your heater core may be clogged or not flowing properly. The [heater core]((https://www.yourmechanic.com/services/heater-is-not-working-inspection) is a small radiator like unit that circulates the hot coolant from the engine through the heater core which then uses this warm coolant to heat the inside of the car with the help of the blower motor that blows the warm air through the vents inside the car. The other possibility is that the thermostat may not be allowing the engine to reach a normal operating temperature and since the engine’s warm coolant is the essential source of the heater core supplying heat to the inside of the vehicle, this can impact the warmth of the heat inside the vehicle. I would suggest having an expert from YourMechanic come to your location to diagnose your heating system.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. Q: Heater only blows cold

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Transmission problem

Check the linkage from the gear shifter to the manual lever on the transmission. You want to be sure the manual lever on the transmission case actually moves into the various gear selection positions (aka, "detents"). If the gear shift...

Q: Jeep takes has trouble starting initially and now has a cylinder 6 misfire

The misfire could be caused by a lack of fuel pressure. Cylinder 6 is usually the last cylinder to be fed by the fuel rail, and when the pressure is low, it can suffer from a lack of fuel. But,...

Q: Clutch Problem with Jeep Patriot

The clutch system does have several parts that if worn or failing could account for the rattling noise. The system would have to be inspected first hand though to pinpoint the exact issue and estimate the cost. If you desire...

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.