Skip the auto shop - Our mechanics make house calls

Q: Heater not working reliably, is it caused by a bad thermostat?

asked by on

During winter last year, upstate NY... like 10 degrees outside, drive to work...NO HEAT... 20 minute ride and i warmed car up for 10 minutes before i left for work. no heat... other cold days, will be driving and heat on and NO HEAT, then in an instance HEAT... i figure thermostat bad...opening inconsistently. sound like the issue? two days ago, had 37 degrees here in NY state...drove to work...NO HEAT...just blowing cold air. Driving home later, got heat.
thanks tom

My car has 88000 miles.
My car has an automatic transmission.

A: From what you've described, it sounds l...

From what you've described, it sounds like you have a stuck open thermostat. I'd recommend replacing the thermostat to see if this is the cause of the slow heat up of the vehicle since it's a relatively quick repair. In an area like that it sounds like you'll will need the heat in the winter very badly and as soon as possible. I would also recommend getting a coolant flush as it may help clear any possible blockage in the heater core. To avoid any unnecessary repairs, consider YourMechanic, as one of our mobile technicians can come to your home or office to diagnose your heating issue and make the necessary 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!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Save up to 30%

Get a quote

What others are asking

Q: AC causing knocking sound.

The knocking noise is the temperature blend door actuator trying to move the blend door. The actuator would need to be checked and replaced. I recommend having a certified mechanic, such as one from YourMechanic, come and inspect your vehicle's...

Q: Is it safe to remove a thermostat from my lexus car?

No, it is not safe to remove the thermostat in any car. The thermostat helps a car regulate the engine's temperature and is a needed component. If you keep having issues with your radiator bursting then a few things can...

Q: What should I do if I have to leave my car for a long period of time?

If your vehicle is going to go more than two weeks without being driven, then you should run the air conditioner before leaving it. Turn your car on, leave it idling, and turn the air conditioner on its highest setting...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
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...