Why Is The RV Air Conditioner Not Blowing Cold Air?

Every summer, thousands of RV owners head out on the open road to enjoy their favorite pastimes. But it can get damn hot inside the rig, especially when you are camping in a hot area, such as Texas, Arizona, or Nevada. Just imagine how hellish it can be if your RV air conditioner not blowing cold air because of some problems!

Why is my RV AC not blowing cold air? RV AC units are designed to draw in the fresh air and push it through the system to make it colder before releasing. You need to check several parts when it fails to cool the air.

RV Air Conditioner Not Blowing Cold: Why Does This Happen?

There are a few different reasons why the camper AC not blowing cold and some ways to fix it. We’ll go through some reasons and some troubleshooting solutions, so you can be back on your way in no time.

Check the voltage of the power source

All electrical appliances need ample power supply to operate. So, a problem with the power seems to be the most likely reason for RV AC not blowing cold. The voltage might be too low or the power source could be faulty. If the voltage is at or less than 110 VAC, the AC unit will not function effectively.

Make sure to check your batteries and fuses first. It may seem simple, but it can save you some time and frustration if everything seems to be in order there. If the voltage is low, charge your batteries or find a different power source.

A malfunctioning thermostat

When the RV air conditioner not cooling, you may want to check the thermostat. The problem could be because of a worn-out thermostat or its malfunctioning temperature sensor.

rv thermostat
The thermostat could be faulty. (Credit: The Drive)

If the thermostat cannot read the actual temperature, it sends a wrong signal to the AC’s compressor, making it do nothing. But the fan still spins to move the air out. The result is that the RV air conditioner not blowing cold.

To solve this issue, check the thermostat’s power source. If it runs on AA batteries, changing them may make the thermostat work again. Or, check the wiring if it receives its energy from a 12V power outlet. You may need to replace the thermostat if it completely burns out.

The RV AC not properly sized for the rig

Another common cause of why the RV AC not cooling enough is because it might be too small for the space. This can be especially true if you are looking to cool a larger area.

There’s no way an 8,000 BTU unit will keep the inside of your 30-foot RV cool enough on 100-degree days. You’ll need at least an 15,000 BTUs or 18,000 BTU RV air conditioner to keep the rig cool even during heatwaves. However, don’t go for too large units like a 20,000 BTUs air conditioner because it will consume a high amount of electricity.

Examine the AC fan

If the RV air conditioner cooling system is working, but you still feel hot air coming out of it, there could be a problem with the fan. The blades might be caked with dirt or bent. You can try to clean them up or replace them if they are heavily damaged.

It’s also possible that the bearings in the fan are worn out. You should also check the fan motor and capacitor. If this is the case, you’ll need to replace the entire fan unit.

The vent-covering flap may be stuck

When the RV air conditioner not blowing cold and you’ve checked all of the above, there’s a chance that the vent flap may be stuck shut. In that case, the AC unit will not work even if it gets cool outside because there is no open path for the cold air to enter inside.

Fix this by checking if the vents are all properly sealed. It can also be a good idea to clean the vents if they are clogged. You may even need to lubricate or replace the flap mechanism that opens and closes the vents as needed.

The AC unit is clogged with dirt

If your Dometic RV air conditioner not blowing cold air (or the AC unit from a different brand), dirt is one of the main reasons. What you might see as the normal accumulation of dirt or dust can actually be a bigger problem.

The flaps are not the only areas where lint or dirt can pile up. This build-up can also occur in the vents where the cold air blows out, which makes it hard for this air to reach inside.

camper air conditioner not cooling
A dirty air conditioner will not work properly. (Credit: RV Repair Club)

We recommend using a vacuum cleaner to clean out the unit. Also, check all other parts where lint and dirt can accumulate, like the fins of the condenser coils. A dirty condenser will overheat easily and not run to its full capacity.

Check your ducted air conditioner

The problem of a camper air conditioner not cooling can also happen because of the type of AC unit you have in the rig. There are commonly two types of RV air conditioning systems – ducted and unducted. Some issues with the first type can easily cause the RV air conditioner not blowing cold.

A ducted air conditioner functions as a central cooling system. With a network of ducts in the ceiling, it supplies cold air to all parts of a rig. If these ducts leak somewhere, the system will lose cool air, leaving the rooms hotter than they are supposed to be.

Fixing this problem is quite simple. You will just need some foil tape and a weather seal. Find out the leaking or damaged parts and repair them. If a part is too damaged, you may need to replace it with a new pipe.


RV AC not blowing cold air? There are many causes for this but it may be fixable so don’t give up hope! Check your fuses, inspect your thermostat, and make sure the AC unit is properly clean before contacting a professional to diagnose the problem.

Scott Wilson
Scott Wilson
Scott Wilson is a seasoned RV traveler and professional mountain biker with a great sense of humor. After earning a Master's degree in Automotive Engineering from Columbia University, Scott spent years working as an RV technician at Camping World and Outdoorsy. Today, he enjoys exploring the US in his fifth wheel and truck with his wife. With over 15 years of RV living and road tripping experience, Scott now shares his knowledge and expertise as a travel blogger, helping others make the most of their RV adventures.

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