5 Symptoms of a Clogged Heater Core
As winter sets in, a functioning heating system is something to not take for granted. But when frigid temps reveal a clogged heater core, your commute gets that much worse. This vital component regulates cabin warmth, so blockages cripple comfort.
Continue reading to learn the common symptoms of a clogged heater core, what causes the issue, and how much it will cost to either flush or replace the heater core.
What is a Heater Core?
A heater core is a heat exchanger that radiates heat into a vehicle’s cabin. This heat originates from engine temperature coolant that flows throughout a vehicle’s heater core, via small tube-like passages.
A vehicle’s blower motor forces air across a heater core, dispelling heat through the adjacent duct-work. As a result, warm air fills a vehicle’s cabin, thereby stopping winter’s chill in its tracks. The end result is a comfortable commute for drivers, even in the face of bitter cold seasonal temperatures.
A heater core features inlet and outlet junctions at a vehicle’s firewall. Coolant lines are affixed at these junctions, courtesy of hose clamps or quick-connect unions.
Some vehicles regulate the flow of coolant through these hoses, by way of a specialty heater control valve. This valve is typically controlled by vacuum, or electrical means, and actuates in response to control head input.
The heater core itself is mounted deep beneath a vehicle’s dash, in close relation to the interior side of the firewall. As a result, heater core-related issues are typically diagnosed by analyzing one or more symptoms associated with the failure at hand.
Therefore, it is extremely important to recognize and understand the various symptoms associated with a faulty or obstructed heater core.
Clogged Heater Core Symptoms
There are numerous signs that often accompany the presence of a clog within a vehicle’s heater core. While the symptoms associated with such a failure often differ on a case-by-case basis, several symptoms tend to be prevalent in the majority of cases.
The following are several of the most common symptoms of a clogged heater core or a bad heater core in general.
1) No Heat
The most common symptom of a clogged heater core is a general lack of heat. When coolant is unable to circulate through a vehicle’s heater core, heating efficiency is severely diminished.
As such, one can expect a frigid commute, with little reprieve at the hands of their hobbled heating core.
2) Sub-Par Heat in Extreme Cold
In certain cases, your vehicle’s heat might prove sufficient during periods of mildly cold weather, only to fall flat when the extreme cold takes hold. This condition is indicative of a partially clogged heater core.
While enough warm coolant is allowed to flow to provide some heat, the system’s overall heating capacity is greatly reduced. In such instances, a thorough flush will often restore a system to full functionality.
3) Possible Overheating
Can a bad heater core cause overheating? In most cases, a clogged heater core, by itself, will not cause overheating. However, when combined with additional issues, engine overheating may result.
This is often the case when cooling system efficiency is already compromised, such as in the case of a faulty water pump or a partially clogged radiator.
4) Foggy Windows
One of the first signs you may notice in cool weather are foggy windows. When the heater core is not functioning as it should, it can’t provide enough heat to the cabin, causing condensation to build up on the inside of the windows. This condensation may even turn to frost on the inside windshield.
This type of fogging will be persistent and not just for a couple minutes while normally warming up your vehicle. This particular symptom can impair your visibility while driving and make it difficult to see clearly so caution must be taken.
5) Wet Carpets
While not too common, a clogged or faulty heater core can sometimes leak coolant, which can seep into your car’s interior and cause the carpets to become wet or damp. This can lead to unpleasant odors and potential mold growth. Check for moisture near the passenger footwell, as this is a common location for heater core leaks.