Some car heater cores are completely replaceable, which can cause labor costs to go through the roof. Some mechanics may offer the option to simply bypass the heating element. It’s not a perfect solution, but we can definitely sympathize with this option when all of a sudden you have such unexpected expenses in your lap. There are other ways to solve this problem.
If attaching a heater core to your car is really not possible before you start diving in cold weather, then a portable car heater is a viable option. However, there are a few things to keep in mind:
- Household heaters (even portable ones) are not always safe for automotive use.
- While some propane heaters are (relatively) safe for indoor use, they should never be used in moving vehicles.
- A 12V portable car heater requires electricity, which can cause problems if you have a weak alternator or many other accessories.
What it boils down to is that even the most best electric car heater won’t replace your broken car heater, it doesn’t mean you have to drive through icy conditions.
Residential heaters as portable car heaters

Because residential space heaters are designed to heat relatively large volumes of air, it’s likely that you could use one to heat your car. And while it’s true that just about any heater puts out enough heat to heat you up quickly, there are two potential problems with this solution.
- Residential space heaters are not intended for use in small enclosed spaces. They usually come with warnings to keep flammable items (like your upholstery, etc.) 2 feet, 4 feet, or even further away from the front and back of the unit. Inside a car or truck, this is usually not an option. So while you may be fine if you install a heater on the floor of your car, you do so at your own risk.
- Another issue with using a domestic heater is power. You will need install an inverter which provides enough power to run the heater, and even then you may find yourself in a situation where your generator cannot keep up with demand.
There is a lot more information about electric vehicle heaters .
Portable propane heaters
Although some portable propane heaters relatively safe for indoor use, these heaters carry a risk of fire or suffocation. Propane heaters that use open flames should never be used in a vehicle due to the risk of fire, and heaters that rely on incomplete combustion carry the risk carbon monoxide poisoning .
Portable propane heaters that are considered safe for indoor use usually include a safety valve that kicks in if oxygen levels get dangerously low. This makes them relatively safe to use indoors, but we still don’t recommend using it in your car while driving.
Portable 12V car heaters
The best and safest alternative to your factory heater is 12 volt heater specially designed for the automotive industry. However, you will generally find that those designed to plug into your cigarette lighter won’t generate enough heat. This is because the accessories that are connected to cigarette lighter socket, can only draw high current (typically 10 or 15 amps) without fuse blown .
Car heaters larger 12V must be connected directly to the battery (usually with a built-in safety fuse) in order to get enough power to produce the heat you need during the cold winter months.
As for how well work these heaters your mileage will vary. They usually don’t produce as much heat as a factory heater, but if you moderate your expectations, you shouldn’t be too disappointed. Of course, you still need to think about how much power the heater consumes. If your generator is not up to the task, your best bet is to save up enough money to get the problem right.