What Components of the Heating and AC System Are Most Likely to Fail?

The average automotive heating and cooling system (HVAC) is actually very complex, and they’re not connected to one another outside the cabin. Yes, your HVAC controls allow you to switch from warm air to cold, adjust the fan speed and more, but these are actually two completely separate systems and they operate independently of one another. As such, there are several components in both the heating and AC system that are prone to wear and tear and can fail over time.

Heating components

The most likely components of the heating system to fail are as follows:

  • Thermostat
  • Low Coolant
  • Heater Core
  • Radiator Cap (pressurized system)

AC components

The most likely components to fail in your car’s AC system are very different, and include the following:

  • Compressor and/or clutch (many cars use a combo unit that must be replaced if the clutch fails)
  • Low Refrigerant (caused by leaks in the high or low pressure side)
  • Serpentine Belt (drives the compressor and clutch)
  • Compressor Switch (controls compressor and clutch cycling)

While these are some of the most common parts of the heating and AC system to fail, they are just the tip of the proverbial iceberg. Your car’s HVAC system is complex, and requires a significant number of components in order to operate correctly. Professional diagnosis and repair is vital if you’re experiencing problems.


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Ben

41 years of experience
1410 reviews
Ben
41 years of experience
Volkswagen Beetle L5-2.5L - Heating AC - Houston, Texas
i am well satisfied with Mr Smith working on my car(s). He replaced the Jaguar fuel pump like an expert, and then he diagnosed the VW bug ac compressor and fixed it on the spot. I would recommend him to anyone with a car issue
Nissan Altima - Heating AC - Houston, Texas
Incredibly nice and took the time to show me the problem, including comparison pictures between my unit and what a new unit should look like.

Peter

43 years of experience
1321 reviews
Peter
43 years of experience
Saab 9-3 L4-2.0L Turbo - Heating AC - Phoenix, Arizona
He knows what he's doing. Very polite and explained everything. I would no doubt use him again. I highly recommend him.
Mazda Miata - Heating AC - Peoria, Arizona
We are so thrilled to have found Peter as our new mechanic. He is very thorough and knowledgeable. He is also friendly, professional, and extremely honest. He explained to us exactly what services were needed on our vehicle to repair the air conditioner and provided us with an written estimate of the cost. He literally saved us thousands of dollars in repair costs. A local major competitor quoted us a repair cost of a minimum of $1,400 and said that the cost would go up to $2,400 if they discovered an additional part was required. Peter charged us only $202, plus performed the work at our home. The air conditioner in our 2004 Mazda Miata has honestly never worked so great--it always blew out warm air. We just assumed it was how that particular car was manufactured. We would highly recommend Peter to anyone who is in need of an experienced and honest mechanic.

Pedro

31 years of experience
78 reviews
Pedro
31 years of experience
Chrysler PT Cruiser L4-2.4L - Heating AC - Portage, Indiana
Pedro was wonderful! He was early first and foremost. He was very professional and he explained things to me. He worked quickly and was very thorough. Very happy with his service.

Manuel

32 years of experience
580 reviews
Manuel
32 years of experience
Ford Taurus V6-3.0L - Heating AC - Long Beach, California
Good guy. Knows his stuff. Knowledgeable and straightforward with diagnostics and repair costs. I’d love to work with him again! Thank you Manuel!

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