How do you fix a stuck thermostat?

Author: Mara Stiedemann II  |  Last update: Wednesday, November 26, 2025

This is an easy problem to solve yourself by simply removing the plastic outer casing and, with a very soft brush, delicately brushing off its coil and contact surfaces. It is most effective to clean the thermostat first at its lowest setting, then again at its highest setting.

How do you unstick a stuck thermostat?

Yes, you can fix a stuck closed thermostat by first allowing the engine to cool, then locating the thermostat and carefully removing it from the housing, and finally replacing it with a new thermostat and gasket before reassembling the housing.

What would cause a thermostat to stick?

A thermostat may periodically stick due to wear or damage, debris or sludge buildup, incorrect or low coolant, or faulty temperature sensors or wiring. These issues can cause inconsistent engine temperature regulation.

Is it okay to drive a car with a stuck thermostat?

Yes, you can drive a car with a thermostat stuck open, but it's not ideal and could lead to several problems over time.

Why is my thermostat not letting me change the temperature?

Why Won't My Thermostat Let Me Change the Temperature Setting? Locked unit: Check if the child lock setting is activated. You'll need to disable it before you can change the temperature. No power: If the thermostat isn't working at all, there could be a power issue.

7 Signs of a Faulty Thermostat - How to Test & Replacement Cost

Is there a reset button on a thermostat?

Most modern thermostats will have a clearly marked reset button inside the panel. It's usually small and recessed, so you might need a pointed object like a paperclip to press it. For those wondering specifically how to reset air conditioner thermostat models, the process is generally the same.

Why is my thermostat stuck on one temperature?

If this doesn't work, try resetting your thermostat with the reset button, changing the batteries, or cleaning off any dust and dirt inside. If the temperature is still stuck, an electrical or display issue might be to blame. Contact an HVAC professional for further help.

How much does it cost to fix a stuck thermostat in a car?

Car thermostat replacement time is 30 to 60 minutes, depending on the make of the car. It will cost you around $190 to $350, including labor. Thermostat repairs usually take more time, requiring extra time to diagnose and analyze the vehicle's thermostat. It can take up to 2 hours.

What are the symptoms of a stuck thermostat in a car?

Here are five easily recognizable signs that will alert you that the thermostat needs fixing.
  • You Notice Erratic Temperature Changes. ...
  • You Find Incorrect Readings on the Temperature Gauge. ...
  • Your Vehicle Makes Concerning Noises. ...
  • You Find Coolant Leaks. ...
  • You Notice Problems with the Heating System.

What happens if you keep driving with a bad thermostat?

If you drive with a bad thermostat, your car could overheat, causing severe and expensive engine damage. And while it's technically possible to drive without a thermostat, we don't recommend it. Your car will not reach an acceptable operating temperature, resulting in higher fuel consumption and excessive engine wear.

How can you tell if a thermostat is bad?

A bad thermostat can be detected when your AC or furnace is not turning on, your HVAC systems are not turning off, the thermostat not responding, your HVAC system is short-cycling, the room temperature not matching the temperature displayed on the thermostat, and the programmed setting resetting themselves.

How much does it cost to replace a thermostat?

The average cost of a new thermostat, including installation, ranges in price from $50 to $500 or more based on several factors including the type of thermostat, labor costs, the complexity of the installation, and more.

How to fix a bad thermostat in a car?

Thermostat Replacement: If the thermostat is indeed the culprit, it's time to replace it. Locate the thermostat housing (usually near the engine block), drain some coolant, remove the housing, and carefully replace the thermostat.

Can a stuck thermostat affect AC?

However, if the thermostat is not working properly, it can lead to several issues, including inadequate cooling.

How to check if coolant is flowing?

Well check the resivor with the car running if there is a change in fill level when you remove the cap then it is flowing, or keep an eye on the temp dials once the temp starts rising feel the tube that goes from the top of the radiator to the engine, if it feels warm then the coolant is flowing.

How to fix a stuck thermostat?

This is an easy problem to solve yourself by simply removing the plastic outer casing and, with a very soft brush, delicately brushing off its coil and contact surfaces. It is most effective to clean the thermostat first at its lowest setting, then again at its highest setting.

Is it OK to drive car with a stuck thermostat?

When a thermostat gets stuck open, it'll allow coolant to circulate continuously even when it's not needed. Unfortunately, that will overcool the engine and cause it to operate below its optimal temperature range. As a result, the engine will lose fuel efficiency, and its components will experience excess wear.

How to tell if your thermostat or water pump is bad?

Here are signs you've got a bad pump or thermostat.
  1. Corroded Cooling System Parts. Both of these cooling system parts can get corroded if they start to leak slowly. ...
  2. Leaking Engine Coolant. ...
  3. Erratic Temperature Changes. ...
  4. Poor Coolant Circulation. ...
  5. Overheating Constantly.

Can I replace my thermostat myself?

In most cases, installing a new thermostat is a relatively simple do-it-yourself project that can result in improved comfort and convenience and one that can help you save energy.

What is the life expectancy of a car thermostat?

A car thermostat is designed to last a long time – typically around 100,000 miles or 10 years. However, various factors can impact its lifespan. First, driving conditions play a role. If you regularly drive in hot weather or stop-and-go traffic, your thermostat may suffer additional stress.

How do I fix an unresponsive thermostat?

4 Steps for Troubleshooting Your Thermostat
  1. Reset the Thermostat. Like any other electronic device, sometimes a digital thermostat needs a reset to get it working properly again. ...
  2. Clean Out Dust and Corrosion. ...
  3. Test the Power and Wiring. ...
  4. Adjust the Heat Anticipator.

How do I reset my control temp thermostat?

To reset a non-programmable digital thermostat, you'll need to take the face-off and hold the reset button for five seconds. You can also try removing the batteries for five seconds. Both of these methods should result in a reset thermostat.

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