How Does the Heater Work?
It may seem counterintuitive, but your car’s heater relies heavily on coolant (also called antifreeze). As your car runs, the engine gets hot, and all that heat has to go somewhere to prevent overheating. While a lot of the heat exits through the exhaust, some of it is transferred to the cooling system, where the heat is absorbed by coolant. The hot coolant then flows through the heater core, which you can think of as similar to the little space heater you’d have under your desk.
The heater core warms up, and the blower motor sends heated air through your vents, ideally blowing warm air into the cabin. You usually need to let the engine run for a few minutes before the vents blow warm air because your engine needs to produce enough excess heat to warm the coolant. This process keeps your engine cool while warming you up!
Why Is the Heater Not Working in My Car?
When you switch on the heat in your car, you expect it to blow hot air and warm your frozen toes. But while heating your cars cabin might seem like a fairly straightforward process, plenty of things can go wrong. If you’ve been waiting far longer than a few minutes and your car isn’t blowing hot air, here are some reasons your heater might be giving you the cold shoulder:
Low Coolant
Your coolant levels are essential and easy to check. Coolant is typically in a transparent reservoir under the hood of your car, with “minimum” and “maximum” lines indicating where the fluid level should be. If your coolant is too low, there wont be enough warm liquid to heat the heater core.
Wait until your engine has cooled to check the level; otherwise, the fluid may still be hot. Otherwise, the system will be under pressure and could cause personal injury. If it is below the minimum level, fill the reservoir to the max line using the products recommended in your owner’s manual.
Low coolant levels might mean you have a leak. If you refill your coolant reservoir only for the level to quickly drop again, you should bring your INFINITI to the nearest service center to have a professional take a look.
Thermostat Is Broken or Stuck Open
The thermostat is located between the radiator and the engine and uses the engines temperature to regulate coolant flow. If the thermostat is broken and stuck open, it can allow coolant to flow continuously and run inefficiently. A concern with the thermostat staying open could reflect poor heater operation.
Restricted or Leaking Heater Core
Since the coolant-warmed heater core is where the warm air originates, a broken heater core can result in lukewarm or cold air blowing through the vents. If you notice a sweet-smelling (think maple syrup) fog/mist blowing into the cabin when you crank the heat, it could be a sign that your heater core is the problem.
Jammed Blend Door
The blend door is the mechanism that switches between cool and hot air when you adjust the settings in your car. If it’s jammed, cold air may come out when you turn on the heat because the door doesn’t move as expected. A jammed blend door may cause a knock or click when you turn on the heat.
Damaged Heater Control Valve
Typically found on older vehicles, the heater control valve acts in place of a blend door. This component is also what you’re adjusting when you change the heater settings in your car. If your vehicle has one, you may have a heater control valve issue if the air temperature doesn’t change as expected.
Air Bubbles in the Coolant
Do you hear gurgling coming from your engine? That could mean air bubbles in the coolant are making their way into the heater core. A coolant leak or head gasket concerns could cause these air bubbles.
Blown Fuse or Electrical Concerns
You depend on the dash controls to help you adjust your heater settings, but these knobs and buttons need to send the right signal for the rest of the system to kick into action. If you’re twisting the temperature dial and hitting the vent buttons but nothing is happening, you may have electrical concerns preventing the signal from reaching the system or HVAC controls.
Help Keep Your Heater in Great Condition
Car not heating up properly? It only takes getting left in the cold once to want to ensure that it never happens again. Follow these simple maintenance tips to help keep your heating system running smoothly:
- Regularly check the coolant level. When you get your oil changed, the technician will typically check your coolant level and top it off if needed. Yet another reason not to put off your oil change! You can also regularly check the coolant at home to help maintain its level and prevent car heater issues and engine overheating.
- Don’t skip your annual inspection and winterization. In addition to the standard annual inspection at your local INFINITI service center, you should also winterize your vehicle. Winterizing means checking your battery, windshield wipers, coolant, and even blasting the air conditioner! This can help you catch and fix any potential heater problems early.
- Keep an eye out for leaks. If you start noticing puddles under your INFINITI, take your vehicle in to check for leaks. These can be early warning signs of your vehicle losing essential fluids like coolant, and you want to address the leak before it can cause further damage.
A broken heater can have many causes, but you don’t have to get left in the cold! Help keep your heater in top shape with INFINITI Parts & Accessories. Shop online for OEM HVAC replacement parts, including fans, heater cores, thermostats, and more. And dont forget you can visit your local INFINITI service center for help with installation.