Skip the auto shop - Our mechanics make house calls

Q: If the thermostat is bad would it cause the heater core to not work properly?

asked by on

I have read online that if the hoses leading to the radiator from the thermostat are cold then that means the thermostat is bad, but would that be the reason why my defrost doesn't work properly? When I start the vehicle I smell what could be antifreeze, just not sure if I should jump to replacing the heater core or hope the thermostat dose the trick.

Hello - you are correct. If the thermostat is stuck open, not allowing the engine to warm up properly, there won’t much, if any, heat in the passenger compartment. However, if you are smelling coolant in the passenger area, chances are the heater core is leaking as well - not a happy occasion. I would recommend a heater inspection by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, confirm this diagnosis, and give you an accurate assessment of damage and cost estimate for repairs.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!
  • Home
  • Questions
  • If the thermostat is bad would it cause the heater core to not work properly?

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: Coolant doesn't circulate and is leaking into coolant tank

Hello. If the coolant only leaks when the engine is running, then it is typically a failing water pump. This is the most common thing to leak under these conditions. The water pump should be checked for signs of leakage...

Q: The engine is running hot.

The seal or gasket is not sealed properly on the thermostat housing. A loose bolt, torn gasket, or wet silicone will cause the thermostat housing to leak. If you need further assistance with a coolant leak, then seek out a...

Q: Location of thermostat.

Hello, thank you for writing in. While it is strange to think the thermostat can be located on the lower radiator hose, this is common practice for some manufactures. The concept works exactly the same. The coolant entering the radiator...

Related articles

How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...
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.