No heat in a Michigan winter is more than a comfort problem, because the same system defrosts your windshield. AutoTech Clinic finds why your heater is not working, whether that is low coolant, a stuck thermostat, a plugged heater core or a blend door that has failed, and repairs it at our Dearborn shop.
We measure the temperature at the vents and the temperature of both heater hoses before we quote anything. Those two readings narrow the cause down fast.
- How Long
- From about 1 hour for a thermostat to a full day for a heater core.
- Same Day
- Usually finished the same day.
- Vehicles
- Foreign and domestic, cars through trucks.
Signs You Need Heater Repair
- The heater blows cool air even after the engine warms up
- Heat works when you are driving but goes cold at a stop light
- Warm air on one side of the car and cold on the other
- The temperature gauge takes a long time to reach normal, or never does
- A clicking or knocking sound from behind the dash when you change temperature
- The windshield defrosts slowly or not at all
What We Do
- 01
Measure Vent Temperature
We take a reading at the vents and compare it against what the system should produce at full heat.
- 02
Check Coolant and Thermostat
Low coolant and a thermostat stuck open are the two most common causes of no heat, and both are inexpensive to fix.
- 03
Feel Both Heater Hoses
If one hose is hot and the other is cool, flow through the heater core is restricted. That is a simple test that saves a lot of time.
- 04
Test the Blend Door
We command the blend door with the scan tool and listen for the actuator. A failed actuator is a common cause of heat on one side only.
- 05
Repair and Verify
After the repair we bleed the cooling system properly, bring the engine to temperature and retest vent temperature on both sides.
Why Heat Matters for Safety Here
In a Dearborn winter the defroster is what keeps your windshield clear. A car with no heat has no working defroster, and that is a visibility problem before it is a comfort problem.
It is also a warning sign. Low coolant causing no heat usually means the system is leaking somewhere, and the same leak can lead to an overheat that damages the engine.
Heat at Speed but Not at Idle
If the heat works while driving but fades at a stop light, the system is marginal. That usually points at low coolant, air trapped in the system or a water pump that is not moving enough fluid at idle.
It is an easy symptom to live with until the first truly cold morning. We would rather test it in October than have you call us in January.
What Affects the Cost
We quote your vehicle specifically after inspecting it, because these are the things that move the number up or down:
- Whether the fault is coolant, thermostat, actuator or heater core
- How much dash disassembly is needed to reach a blend door actuator
- Heater core replacement, which is among the most labor intensive jobs on a car
- Flushing a partly restricted core versus replacing it
- Dual zone climate systems, which have more actuators to test
Call (313) 277-7200 with your year, make and model and we will tell you what to expect before you come in.
Why AutoTech Clinic
AAA Approved
An inspected facility that has to meet AAA standards for equipment and training.
Photos First
You see what we found and approve the price before anything is taken apart.
Same-Day Service
Parts on hand for the vehicles we see most, so you are not waiting on a delivery.