Overheating is the most common symptom of a failing thermostat. Due to corrosion or aging, your car's thermostat can get stuck in a closed position. If this happens, the thermostat will not let the coolant reach the radiator, and, as mentioned above, the engine will overheat, causing severe damage.
You Find Coolant Leaks
If the thermostat fails in its closed position, then this can cause the coolant to overflow and leak out of the thermostat container when the engine overheats. If you find coolant leakage, it could be a sign that the thermostat has broken and requires replacement.
When overheating is caused by a deteriorated cooling system part, the Fail-Safe has a secondary stroke that activates a precision engineered piston that automatically locks the valve into a wide open position allowing coolant to circulate freely.
Overheating is the most common symptom of a failing thermostat. Due to corrosion or aging, your car's thermostat can get stuck in a closed position. If this happens, the thermostat will not let the coolant reach the radiator, and, as mentioned above, the engine will overheat, causing severe damage.
You can try to clean or knock on a thermostat to get it unstuck. However, that's only a short-term fix you should not rely on. Remember: a stuck thermostat is terrible news for your engine, regardless of whether it's stuck open or closed. So, the best thing you can do is replace your stuck thermostat with a new one.
THE MECHANICS BEHIND A THERMOSTAT
How does a thermostat sense the temperature and know when to open and close? It's not magic. Instead, the thermostat has a wax-filled cylinder on its side. As the engine temperature rises, the wax expands and steadily pushes on a rod that opens the thermostat, allowing coolant to flow.
Thermostats, like many other electrical appliances, will malfunction if they're allowed to get too dirty. Dirt, dust, and debris can pose problems for both electrical and mechanical components, causing your thermostat to fail. Turn off the power source and remove the thermostat's cover.
Once the engine heats up to its designed operating temperature, typically around 90-100 degrees Celsius, the thermostat opens. This opening allows the hot coolant to pass through the radiator, where it's cooled down before returning to the engine, maintaining a constant, optimal temperature.
As the engine reaches its operating temperature, the thermostat gradually opens, allowing coolant to flow to the radiator.
However, if the thermostat gets stuck in the closed position, the coolant can't flow through the radiator and can make your engine overheat.
Generally, repairing a thermostat costs around $200 to $500. This is the price range you'll find for most vehicles, although some may be higher or lower depending on the circumstances. But if we're talking complete replacement, expect the price to increase by $50.
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.
Yes, many smart thermostats are designed for DIY installation, and manufacturers typically provide step-by-step guides and videos. However, if your HVAC system is older or lacks proper wiring (like a C-wire), the installation might become more complex, and you may need professional help.
The Lifespan of a Thermostat
On average, most thermostats last about 10 years, depending on the model, usage, and proper maintenance. However, many people decide to replace their unit sooner to take advantage of new energy-saving technologies.
Listen closely to your heating system. Unusual noises like banging, clanking or squealing might mean that there are issues with the furnace itself. If the system is constantly cycling on and off it could suggest thermostat malfunctions disrupting the regular heating cycle.
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.