Imagine having no heat in car in the middle of a severely cold winter. Car heaters that aren't reliable will not only make the frigid winter months unpleasant but the car will also be unable to defrost the windows and mirrors, resulting in condensation and ice. So no heat in car will also become a safety problem. Why is your car's heater not working, and what should you do to prevent it?
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How does the car heating system work?
To more easily understand why there’s no heat in car, it’s useful to at least know the basics of how the car heating system works. The heating system in your car isn't very sophisticated. Because your engine works by converting a mixture of fuel and air into a series of little explosions, it generates a lot of heat—enough heat that your car needs a cooling system to keep from overheating.
A car water pump circulates a 50-50 mixture of coolant and water through the engine, a radiator releases some of the heat into the air, a thermostat determines when the engine needs to be cooled and when it doesn't, and coolant—the colored liquid that circulates throughout the entire system.
When the coolant heats up, a few feet of high-temperature rubber line transports it to your vehicle's heater core. The heater core works like a miniature radiator. A fan drives air over the heated fins of the heater core, creating hot air, which is then carried into the cab of your vehicle through a series of vents to warm the inside.
No Heat in Car: What do I do if my heater is blowing cold air?
Before doing some serious troubleshooting when your furnace is blowing cold air, first try turning it off and on. If the air seems heated for a few seconds before switching to cold, the flame sensor may be filthy. If the flame sensor is dirty, your gas burner will not stay lit, causing the air to get chilly soon when the furnace is switched on.
No Heat in Car: What would cause a car to have no heat?
Because, like a house heating system, there are several components working together to heat your car, a variety of things can go wrong with automobile heaters. If one or more of these problems exist, your car may instead vent cool air than heat:
- Issues with the Heater Fan
The first step in troubleshooting is to see if the heater core is filling with the hot coolant required to begin the heat transfer process. This is a simple task. Simply turn the dials to heat once you're travelling at a good speed—say, 40 mph or faster.
If you see even a tiny little bit of warmth emanating from the vents, your heater core is most likely receiving hot coolant. That suggests the issue is most likely with your heater fan. Check your controls to make sure your fan is turned on, then experiment with different fan speeds to see if it's simply a dead speed. If this is the case, replace the fuses in the fan and you should be good to go.
- There’s not enough coolant
If you don't feel even a slight bit of heat while your fan is running at full speed, it's possible that your heater core isn't getting enough hot coolant as the engine warms up. Coolant, which is normally made up of 50% antifreeze and 50% water, is used to keep your car's engine cool, especially during the hot summer months. When you turn up the heat in the winter, coolant is transferred from the engine to the heater core, which then blows warm air into your vehicle.
Because the engine must warm up before the coolant can heat up and deliver heat to your interior, it may seem cool for the first few minutes. The first thing you should check is your coolant level if cool air continues to blow out. When your car's coolant level is low, it won't be able to deliver any to the heater core, preventing it from producing warm air.
Check your coolant level first to ensure that there is adequate liquid to reach your heater core. You won't get any heat if your radiator is very low on coolant. If your levels are normal, you're dealing with a faulty water pump or a stuck thermostat.
- Heater Core Issues
No heat in car can also be frequently associated with heater core issues. The coolant may not be flowing properly through the heater core, the air from the blower motor may not be reaching it, or the heater core's small tubing may be clogged.
In a word, heater cores are cooling system components that resemble tiny radiators. A heater core consists of brass or aluminum tubing that transports hot coolant in and out, as well as fans that spread the coolant's heat. The defrosting and heating functions of a car are controlled by the heater core. The heater cores are usually found in the back of dashboards.
If your automobile isn't pushing warm air into the cabin and the coolant level is fine, your heater core may be malfunctioning. Signs of issues with the car's heater core are fogging inside the car, sweet and fruity odor, coolant being used up more quickly than it should and engine overheating.
The cost of replacing the heater core is usually between $564 and $927, including parts and labor. The parts aren't very expensive, ranging from $80 to $234, but the heater core's position means labor expenses can be fairly high.
Replacement of the heater core is difficult work for a DIY mechanic, but it is doable with the correct tools and enough time. If you have some wrenching skills, it's worth a shot to save hundreds of dollars instead of paying a hefty fee from your local mechanic.
- Heater controls are either broken or clogged
Although your vehicle's heater core is a simple mechanism, it can experience a few common issues. The control buttons can become gummed up and quit working after being used for several years.
The heater core could have a leak if your car overheated, or if you have a wet front floor. There's also a door that opens and closes to let the warmed air in. All of these concerns can be diagnosed by a mechanic. A heater core replacement will cost the part + labor. It won't be cheap, but it won't require a second mortgage to solve.
If your coolant levels are fine and your heater core appears to be in good working order, it’s time to look into the control buttons. You might need to replace some of the control buttons or the heater control valve.
- Thermostat That Isn't Working
Your water pump isn't to blame if your car hasn't been overheating or running hot. Instead, you could have a broken thermostat, which opens and closes cooling system circuits as the engine heats up. If a thermostat is locked in the closed position, coolant will never circulate entirely, leaving you with no heat in car.
If your thermostat gauge remains on the “C” setting even after the engine has warmed up, you may have a faulty thermostat. The coolant will not be sent over to deliver heat to your heater core if the thermostat cannot communicate to the vehicle that the engine is heated, and the air will remain cool.
This issue can be resolved by removing the bottom radiator hose and replacing the thermostat. For more information, consult your maintenance manual. If you don't have the time or inclination to figure out why your heat isn't working, a shop can do it for you—repairs for this type of problem are usually extremely affordable. Installing a new thermostat is a reasonably simple and inexpensive remedy that may get your heater up and running again quickly.
- Water Leaks
A water leak is another significant issue with car heaters worth looking into. Leaks can appear in a variety of areas, so make sure to inspect your hoses, radiator, and water pump for damage. Your car heater will not work properly or there will be no heat in car if any of these three are leaking.
No Heat in Cars: Heater Maintenance
Do not wait for your car heater to have issues to start taking care of it. Here are a few car heater maintenance you can do to avoid issues with no heat in car:
- Keep the coolant in check.
The coolant is important not just for your air conditioning system, but also for your heating system. This fluid travels via the radiator and into the heater core, where it heats the air breathed into your vehicle.
- Schedule an annual inspection for your car heater.
A winterization vehicle service is a good investment since it prepares your automobile for tough conditions before the temperatures drop each year. Your mechanic should verify that your radiator, thermostat, heating core, blower fan, hoses, and belts are all in good working order during this service. If you need any parts replaced or repaired, they'll take care of it right away to avoid a breakdown during your trip.
A car's heating system, unlike your home's furnace, does not have a central heating unit that can be easily replaced. The blower fan, thermostat, and heater core are all part of the system, which is normally located in a difficult-to-reach area beneath the dashboard and can take days to repair if minor issues are not handled right once.
- Watch out for leaks.
Radiator leaks are one of the most typical causes of a faulty heater. Your radiator fluid will leak onto the heater core, leaving your system low on coolant. If you notice symptoms of a leak beneath your automobile or detect a sweet odor coming from your vents, you have a leak. You should take it in for car repair right away so your technician can examine it to see if it needs to be repaired.
Why you should take care of your Car Heating & Air Conditioning Systems
Aside from ensuring that you will not have a problem with no heat in car, here are other reasons why you should take care of your car heating and conditioning systems:
- Heaters help keep the engine cool.
It may seem unusual, but your car's engine cooling system and heating system are inextricably linked. During operation, engine friction and combustion generate heat, which must be dissipated once the majority of it is released through the exhaust system.
Excess heat is released into the atmosphere by a mixture of water and antifreeze moving through the engine block and radiator, and on cold days, that heat can also be channeled into the car to offer warmth for you and your passengers. On a hot summer day, your engine could overheat and, in the worst-case situation, break down completely if you don't have a properly functioning heating system
- The air conditioning defrosts the windshield.
As mentioned earlier, it is the heater that defrosts your windshield. Your air conditioning system is hard at work behind the scenes on frigid winter mornings when you can see your breath but not through your windshield due to a stubborn layer of ice. The air conditioning system helps defrost and defog the windshield by removing humidity from the air.
- Properly working air conditioning and heating system keeps a healthy environment inside your vehicle cabin.
Mechanics will inspect and replace your cabin air filter as part of any normal maintenance routine for your car's heating and air conditioning systems. Pollen, bacteria, dust, and exhaust fumes are trapped by cabin air filters before they reach your dashboard vents, polluting the air you and your passengers breathe. Filters that are dirty or clogged can create a range of issues, ranging from musty odors to headaches, allergic responses, and breathing issues as a result of the fumes, so it's critical to replace them before they become that bad.
A good heating system can make the winter a lot more enjoyable. If you detect any of these problems or can't get heat to blow out of your vents, have your heating system inspected by a reliable local car repair shop. It's critical to fix automobile heating issues as soon as feasible. If you ignore the problem, it could turn into a much greater and more expensive problem in the future.