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.

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・Fair and transparent pricing

Get a quote

What others are asking

Q: Heating unit makes my temperature gauge go up

Hi there. It sounds like there could be the possibility of a low cooling system level. Check the level when the engine is cold and add as necessary. When you turn the climate controls to heat the inside of the...

Q: Temperature gauge jumping

Hello. If possible, it would be good to verify coolant temperature (with a laser thermometer or similar), to confirm that your temperature sensor and gauge are reporting temperature correctly. If so, it's possible that you have a blown head gasket...

Q: Can I Get Cold Air Without Running the Air Conditioner?

All vehicles produced today are equipped with air conditioning systems. If you do not want the air conditioning on but you would like fresh air to come into the vehicle then all you would have to do is turn the...

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...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...