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Q: Heater only blows cold

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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.

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