RV Air Conditioner Not Blowing Cold Air: Causes And Repairs

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What can be more frustrating than a dead AC? A running system that blows hot air! RV air conditioner not blowing cold in the sweltering summer heat is simply torture. Fortunately, there are ways to fix such AC problems.

Troubleshooting an HVAC system requires professional expertise. But if you are someone who likes to do their own work and have some knowledge about RV mechanism and air conditioning systems, you can fix this issue.

RV air conditioner not blowing cold
RV AC not blowing cold is an common issue that RVers have to face!

The Basics Of RV Air Conditioning Units

To identify the root cause of the cold air problem, you should know the basics of the system.

The unit has two main parts – the sealed system and the air moving system.

The first one contains the inner components including the compressor, evaporator, and condenser. These all work together to make the air cool. The air moving system consists of a motor and two fans. These fans move the air across the condenser and evaporator.

Another basic thing you must know is the type of refrigerant that the air conditioner uses. Some old units use R-22 or Freon but the modern air conditioners use R143a.

RV AC refrigerant
R-22 refrigerant is obsolete now.

Sometimes, the AC system blows hot air when it runs out of the cooling liquid. Charge it with more liquid to restore the normal function. However, the R-22 systems are mostly sealed units and don’t have any charging ports. The ban on the production and import of R-22 refrigerant since January 1, 2010, has made it difficult to get it.

RV Air Conditioner Not Blowing Cold: The Causes

There are a few reasons for the AC not blowing cold air. Let’s see what they are and how you can troubleshoot these problems.


Several components can get clogged with dirt and other materials, causing the RV air conditioner not blowing cold air.

Dirt, spiderwebs, and other things can get into the condenser coils and clog the condenser fins. Clean it and also check the foam filter in the intake grate to see if it is clean or not. A soap and water mix is enough to clean the foam filter, but you have to change it if it’s a couple of years old.

Dirt and grime can jam the evaporator and blower motor fins and obstruct the cold air streaming. If there is a leak outside the blower box, use foil tape to seal it.

Related: How to Quiet RV AC


A small hole in any of the components can affect the flow of cold air. Leaks in AC intake and exhaust can cause all sorts of troubles. If wires are poking through the duct of AC intake, seal them up with foil tape so that hot air does not leak into the intake.

If the seal between the exhaust ducts and roof wear off, cool air will blow around the ducts and into the hot roof instead of inside the trailer. You have to close the gaps by using weather seal foam.

The air from intake and exhaust could get mixed if the foam ring in the splitter wears out. Use weather seal foam and foil tape to close out any opening.

Dirty Compressor

Dirt can get into the compressor too and prevent its normal operation. Your RV’s regular maintenance schedule should include cleaning the areas around the compressor. If you are going to leave the RV in the garage for a long time, don’t forget to cover the whole AC unit.

You can clean it by yourself, but taking professional help will be the best practice. Remember to switch the AC off before starting the cleaning task.

rv air conditioner not blowing cold
Dirty compressor is a potential reason.

Condensate Airflow Switch

Some air conditioner models feature an inbuilt safety float switch. If the condenser drainpipe overflows with water, this switch trips and turns off the system. If this is the case, clean the drainpipe and then reset the switch.

Hot Weather

Heat gain inside the trailer is another reason for the air conditioner to now blowing cold air. Most RVs don’t have good insulation because extra-thick walls will eat up the living space. For example, there won’t be much room left if the vehicle has 6-inch thick walls all around.

If you park the RV directly under the sun in extremely hot weather, the heat inside the vehicle will be greater than the AC can pump back out. The solution is parking the RV under a shade like a tree or an awning. Just keep your trailer out of the way of direct sunlight.

One solution to prevent the RV air conditioner not blowing cold air problem is to purchase a high-quality unit that will run for many years showing no trouble. A few more reliable brands selling the best RV air condition units are Dometic, Airexcel, and Atwood. Our experts have compiled a list of best RV AC units with detailed reviews, check it here.

About Chris Coleman

Chris Coleman is an interesting travel blogger and outdoor photographer with a great sense of humor. He owns an RV Accessories shop in New York City so he has the knowledge necessary to provide thorough reviews and give advice on how to choose the right products for RV travel. He puts all that RV knowledge and experience to good use in his sharing posts. Besides product buying guides/reviews, Chris also writes informative articles, how-to articles and RV camping guides in his own interesting viewpoint. Chris’s blog is one of the most reliable information sources for RV campers no matter if you're an expert or a determined beginner.

2 thoughts on “RV Air Conditioner Not Blowing Cold Air: Causes And Repairs”

  1. I have a 2020 5th wheel big horn traveler by heartland. My ac is not cooling right. But I’m parked directly under the sun with no shade and it is 105 degrees outside. Is it just me or could I need freon. I didn’t even know that it ran on freon. But I do take the foam out every month and wash it and put it back in. Am i panicking for nothing or is it just hot out side

    • Hi Holly, thanks for your comment. To make it easier for your RV AC system to reliably pump out cool air when it’s over 100 degrees outside you need to give it some help:
      – Check the air filters on your AC system – replace them on schedule.
      – Keep your air conditioner out of the sun – Shading a roof top AC unit
      – An air conditioner in a RV uses refrigerant/freon to chill air passing over an evaporator coil. RV Air conditioning systems with low refrigerant levels need to have refrigerant added to operate at maximum efficiency.


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