Block Heaters Vs. Remote Starters

Should you use a block heater, a remote starter, or both?

broken down in snow
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Block heaters and remote starters can both help warm up a car, but that doesn't mean they're on equal footing, or that they're even both solutions to the same problem. In fact, block heaters and remote starters are two totally different kinds of technology, and they perform completely different functions.

While block heaters and remote starters are both useful in similar situations, and they can both make your commute a little easier when the mercury plummets, it’s important to point out the differences and note that there are situations where you might even want both.

Do Block Heaters and Remote Starters Accomplish the Same Goals?

Block heaters and remote starters are both useful in cold weather, but they accomplish very different tasks. Block heaters are mostly useful in extremely cold situations, and the benefit they confer is to reduce damage to the engine by starting it cold.

Remote starters, on the other hand, provide the benefit of warming the engine up before you start driving, which can make the cabin of the vehicle more comfortable and improve gas mileage.

The most important difference between these two technologies is functionality. Block heaters are simple electric heating elements that can warm up your engine via a number of different methods, depending on the specific design. This basically prevents the coolant from gelling or freezing, and it can also stop the oil from turning into tar in extremely cold temperatures.

The point of keeping the coolant liquid is that a major component of engine coolant is water, and water expands when it freezes. In a worst case scenario, frozen coolant could crack the engine block, which is a tremendously expensive repair.

Keeping the engine oil from thickening up is a little less important, but it can cut down on engine wear. It also allows the engines of older vehicles to operate closer peak efficiency without needing to warm up, and warm coolant translates to less time sitting in a cold car.

Remote starters essentially just allow you to start the engine without actually being in the vehicle. This allows you to g get your car running ahead of time, which warms up your engine and has the added benefit of heating up the interior of your car if you leave the climate controls on the correct settings.

This is primarily a benefit in terms of comfort, and a remote starter will not prevent damage if it gets cold enough overnight to gel or freeze your coolant.

Types of Engine and Block Heaters

There are actually a few different types of “engine heaters,” and not all of them actually fit into the “block heater” category. They fall into four broad categories:

  • Oil heaters: These don't heat the block directly, but they do heat the oil, and they're best for climates where it doesn't get too cold.
  • Coolant heaters: These also don't heat the block directly. Instead, they heat the engine coolant. This prevents the coolant from freezing in extreme conditions, and some heat also transfers from the coolant into the block.
  • Contact heaters: These are designed to transfer heat directly into the block via physical contact.
  • Heater blankets: These don't specifically heat the block, but they do warm up the engine and engine compartment in general.

How Oil Heaters Work

Oil heaters are heating elements that are typically installed in place of the dipstick or attached to the bottom of the oil pan. In either case, the point of this type of heater is to keep the engine oil warm, which can prevent engine damage and improve gas mileage in comparison to just firing up an engine with freezing cold oil.

These engine heaters work just fine at what they do, and they’re great if you live in an especially cold area, but they don’t do anything to make you more comfortable, if that’s your primary concern.

How Coolant Heaters Work

This one may sound a little weird, because it involves heating engine coolant. The term coolant refers to the fact that the normal function of this liquid is to remove heat from the engine, effectively cooling it. It's also referred to as antifreeze, as it's designed to freeze at significantly lower temperatures than regular water.

When this type of engine heater is installed in a car or truck, it may be inserted in place of one of the freeze plugs in the engine block. Due to this placement of the heating coil, this type of heater is properly referred to as a block heater.

As heat radiates from the heating element, through the coolant in the engine block, the engine oil will typically be warmed up to a certain degree as well. This is less effective than heating the oil directly, but it can have an impact.

Other coolant heaters are designed to be installed in-line with radiator hose instead of directly into the engine block. Some of these can even include a small pump that will circulate coolant through the engine to one degree or another.

Regardless of where the heating element is placed, direct contact with the coolant in the engine means that the coolant will already be warm when you first get in the vehicle. Since hot coolant is the method that most vehicles use to heat up the passenger compartment, warming up the coolant ahead of time means that you’ll have hot air coming out of your vents much sooner than you would otherwise.

How Contact Block Heaters Work

Contact heaters bolt to the engine, usually to the block, and heat it up via that method. They're somewhat similar to oil heaters that bolt to the oil pan, and they can heat up both the coolant and the oil to some degree.

Heater blankets, on the other hand, are essentially just big heating pads with resistive heating elements woven into them. They don’t directly heat up engine oil or coolant, but they do radiate heat into the engine and can be useful in some circumstances.

Remote Starters Vs. Block Heaters

If you park your car outside, and the temperature dips low enough to gel your antifreeze, or turn your oil into thick sludge, then a remote starter won’t do you any good. Even if the remote starter manages to start your engine, it will still suffer damage as it warms up.

If you have a heated garage, then a remote starter can still be of some use, but it's important to avoid running a car inside a garage that's connected to your house, as doing so could lead to deadly carbon monoxide buildup.

Extreme temperatures are where block heaters shine, since they can effectively prevent severe engine damage for a relatively low operating cost. Certain block heaters, specifically the ones that heat up the engine coolant, can also make you more comfortable during your commute by providing warm air from the heater right away.

If the thought of immediate warm air from the heater is what interests you the most, then a recirculating in-line coolant heater will probably do the trick.

Although remote starters are useful in that they can allow you to warm up your car without going outside, it’s important to note that they’re most useful in circumstances where it isn’t cold enough to warrant a block heater, but it’s still cold enough that jumping into an unheated car every morning is extremely uncomfortable.

On that note, you can also pair a block heater, on an electrical outlet timer, with a remote starter. The former will make it safe to start the car, and reduce wear on the engine from running with cold, thick oil, while the latter will allow your heater to take the chill off before you climb in.

Other Electric Car Heater Options

If you’re already running power out to your car to plug in a block heater, and you’ve already set a timer so the heater will kick on a few hours before your commute, you might want to consider using an electric car heater to warm up the inside of the car.

Plugging in a heater to perform this function is actually more efficient than running the engine via a remote starter, and depending on the source of electricity where you live, it may also be better for the environment. Of course, it's important to remember that most residential space heaters aren't exactly safe to use in cars.