Top Reasons Your RV Air Conditioner (AC) Is Freezing Up

‍Maintaining your RV’s AC is a routine part of your annual vehicle repairs, but why does the unit keep freezing up and how do you fix it?

While there are certainly more important components of your RV than the AC, you want to make sure that your unit is working properly before you start your next trip. A common problem that a lot of RVers run into over the years is that their AC unit freezes up on them.

Your RV air conditioner (AC) is most likely freezing up because of excess humidity in your camper or dirty components such as air filters, evaporator coils, or condenser coils. Alternatively, the issue could be caused by a broken or faulty thermostat.

When you buy an RV, you will quickly realize that owning one of these vehicles comes with a considerable amount of maintenance and upkeep. Your camper is loaded with features and components that all need to be assessed before you hit the open road - with your vehicle’s AC being an easy thing to overlook. If you are finding that the unit freezes up when you turn on the air conditioning, you need to troubleshoot the issue to fix it. There are a number of different factors that could be contributing to this problem, which can make pinpointing the source a bit challenging. You will have to diagnose your unit so that you can figure out exactly what is causing the AC unit to freeze up so that you can get your air conditioner back in working order. To help you understand this further, we are going to take a closer look at why your air conditioner is freezing up and what you can do to fix it.

After researching RV troubleshooting forums, I have been able to gather enough information to determine what causes an air conditioning unit to freeze up, as well as how to resolve the problem. My research has indicated that you should always get professional help for your RV maintenance if you are not comfortable working with tools or handling delicate components of your vehicle’s air conditioner.

‍Top Reasons Your RV Air Conditioner (AC) is Freezing Up

One of the first things to start acting up in an RV is the AC. Air conditioning units are notorious for experiencing a wide variety of different issues over the years, especially if you have not been keeping up with routine maintenance.

If you notice that your AC unit freezes up once you turn it on, you are not alone, as this is a pretty common problem. Fixing an AC that freezes up can be very easy or it could require some rather technical repairs. These are the most common reasons why an RV air conditioner will freeze up:

• Humidity
• Dirty Air Filter
• Dirty Evaporator & Condenser Coils
• Faulty Thermostat

Depending on what is causing your unit to freeze, you may need to use specific tools to fix your AC. Whenever approaching RV repairs, make sure that you handle them with care and consideration, as some parts are delicate and can be easily damaged.

In addition, I would recommend that you have your RV and AC owner’s manual handy when conducting repairs. Each vehicle and air conditioning unit can be different and may require a specific procedure for handling parts and components.

How to Fix an RV Air Conditioner that Freezes Up

Before you start working on your AC unit, make sure that your RV is completely off and that no power is moving through the vehicle.

You should also keep in mind that you will have to climb on the roof of your camper for some of the fixes, given that your AC's primary components can only be accessed this way. Let’s dive into how to fix an RV air conditioner that keeps freezing up.

Humidity

It can be easy to overlook the climate of the region you are traveling through when trying to figure out why your AC freezes up. This is a particularly common problem in humid parts of the country.

There are a few different approaches that you can take for fixing this, which you can decide based on what is convenient and logical for your setup.

Option 1: Keep AC on High

Although this is not a guaranteed way to prevent your unit from freezing, you may find that keeping the AC in a high setting will prevent it from freezing up.

When air passes slowly through an AC unit on a humid day, there will be more moisture building up around the coils and components. If the air conditioner is set high, moisture will have a harder time building up and freezing.

Option 2: Dehumidifier

The humidity level of your camper may be too much for a high setting on your unit to solve the issue. In this case, I would recommend buying a dehumidifier for your RV.

You can buy a dehumidifier to control the humidity level of your vehicle, which will ensure that the AC does not freeze up due to excess moisture in the air. This is the best approach for RVers who find themselves traveling through humid regions regularly.

Dirty Air Conditioner

One of the most common reasons behind a lot of AC issues is that the unit is simply dirty. Whether it is overheating, leaking, or even freezing, a dirty air conditioner can easily be causing any of these problems to arise.

Naturally, you will have to clean your unit to fix the issue. However, there are a few different components that you will need to target.

Air Filter

Let’s start with cleaning the easiest component first - the air filter. Your air filter is quite easy to reach and you should be able to access it from the inside of your camper.

1. Remove Vent Cover

The vent cover is usually held in place by a couple of clips, which you can remove by pulling.

As you pull on each clip, you will notice your vent cover unlatch with the air filter on the other side.

2. Clean Air Filter

Your RV’s air filter is not a delicate component and you can clean it using standard household cleaning supplies. For most cleaning jobs, some hot soapy water and a cleaning rag should be enough.

Evaporator & Condenser Coils

After your air filter, you should clean your evaporator and condenser coils. These components are located inside the unit, which will require you to get onto the roof of your camper.

1. Remove Shroud & Cover

Your unit is contained and you will need to remove the shroud and cover of the AC to access the evaporator and condenser coils. To do this, you will need a screwdriver, most likely a Philips Head (depending on the make and model of your vehicle).

Vacuum Coils

If you noticed that your coils are completely covered in dirt and debris after you removed the shroud and cover, it’s a good sign that it's been a while since they have been cleaned or that they have never been cleaned at all.

To start, I would recommend gently vacuuming the coils first to get off as much of the dirt before you scrub them with water and cleaning products.

Clean Coils

Your evaporator and condenser coils are sensitive components of your RV’s AC, so I would recommend approaching this part of the cleaning process with caution.

You can use either a soap and water mixture to clean the coils or you can opt for an official cleaning product designed for this type of work. You can then scrub the coils gently to remove any of the remaining dirt and debris using a soft brush or cloth.

Faulty Thermostat

While this is a less common reason for an RV AC to freeze up, it is not unheard of. The unit may be experiencing the issue due to the thermostat being faulty or damaged.

If the unit and vehicle are old, then there is a good chance that the thermostat simply got worn out over time. However, if you just had your unit and vehicle serviced, there is a good chance that the thermostat is faulty.

Test the Thermostat

To determine if this is the reason behind the unit freezing, you need to test your AC’s temperature gauge to confirm whether it's accurate.

You can do this by setting your vehicle’s air conditioner to a specific temperature. Using a thermometer, check the temperature of the room with the camper fully sealed to confirm if the thermostat is giving you an accurate reading.

If the thermostat and thermometer give you the same temperature, then you will know that this is not the problem. However, if the temperature reading is different, this will be a telltale sign that your thermostat is causing the issue.

Replace or Reset the Thermostat

The process of replacing an RV’s AC thermostat can vary depending on the make and model of the air conditioner.

Before you go out and buy a new thermostat for your AC, I would recommend trying to reset it first, as this can sometimes fix the issue without any actual repairs being necessary. You will need to check your vehicle’s manual to confirm how to rest your specific AC model’s thermostat.