Troubleshooting and maintaining you RVs air conditioning system can be complicated for many RVers but there are some things you can do on a regular basis or even a simple repair you can do on your own before you call in a professional. Remember, your RV is in motion much of the time so quite often a simple fix of a common component on your AC system such as a breaker, fuse, loose wire, or thermostat is all you need and regular maintenance will help to prevent some of these breakdowns while you’re traveling.
While changing filters and cleaning the air intakes once a year may be enough to satisfy a home air conditioning system, more preventative maintenance will be needed for your RV if you are traveling full-time and even if you are just using your rig occasionally. A lot of folks that are just “weekend warriors” or occasional RVers will have problems with their cooling systems if they don’t look after them even when they aren’t in use.
Understanding your RV’s air conditioning system components
While there are several parts that make up an RV air conditioner, in this section of the article, I’ll explain most of the major components and how they work to cool off your RV.
Evaporator: This is the part in your AC unit that resembles a vehicle radiator. It takes the refrigerant, which many people refer to as Freon®, and it distributes that gas through the evaporator to remove moisture from the air being drawn in through your RV. By doing so, it reduces the temperature of that air exponentially and it is returned to your RV much cooler. You should allows keep in mind that the refrigerant acts as an extractor, as it travels through the coils in the evaporator, it is not adding cold air. Instead, it’s extracting humidity and heat. This in turn results in cooler air and that is the conditioned air that is returned to the inside of your RV.
On a side note, while this gas is in fact a refrigerant, it is actually a trademarked name from the Chemours Company, which is a subsidiary of the Dupont corporation. Over the last 30 years, Freon® has become widely criticized as a gas that contributes to the depletion of the earth’s ozone layer and in many cases has been replaced with more eco-friendly gasses. With that said, for the rest of this article, I will refer to any gas or liquid coolant used to cool your RV as a refrigerant.
Condenser: In the process of conditioning air, your refrigerant is taken from a liquid state to a gaseous state and then returned to liquid state again. A condenser is used in air conditioning systems as a heat exchanger to cool down and condense incoming gaseous refrigerant vapor back into a liquid state after it has circulated through the coils of the evaporator.
Compressor: Your compressor is designed to add pressure to your liquid refrigerant which results in its transformation from a liquid state to a gaseous state. This gas is then pumped through the evaporator and then it’s returned back to a liquid state. Extremely high pressure is required during this part of the process and that is why the return refrigerant lines are reduced in diameter so dramatically during the return process. As a rule, your compressor will contain a holding tank for the liquid refrigerant and a motor that will pump the coolant under high pressure that will compress the coolant from a liquid state to a gaseous state and then return it to a liquid state.
Squirrel Fan: This fan is located on the opposite side of your evaporator and it’s designed to return the cooled air back into your RV after it has flowed over the evaporator and its humidity had been removed.
Exhaust Fan: Because the compressor and its motor run anytime your air conditioning unit is working, they create a great amount of heat. This fan blows that heat outdoors and away from your AC unit.
Thermistor: While this part may seem inconsequential for many people, it’s actually a critical component for ensuring that your AC unit works properly. The thermistor communicates between your control panel for the AC unit and the evaporator. In a nutshell, if your evaporator begins to ice over, the thermistor will shut down the AC system until it’s safe to resume normal operation.
Tips before storage
Prolonged storage can sometimes wear on your RV just as much as regular use. Brakes can set up and things like appliance motors can freeze up too. So, it stands to reason that your AC system can sometimes fail as well if not used enough. If you are storing your rig for long periods between uses then I recommend preventative maintenance such as starting it up or plugging it in occasionally and starting the furnace, refrigerator and the AC systems.
Have a planned maintenance day
If you are a part-time user, you may want to consider setting one day aside once every couple of months or few weeks and testing out your RV and making sure all the systems are in working order. You can even make it an occasion for those days and invite your friends and family. For example, let’s say you have an RV you only use a few weekends a summer and the rest of the time it sits next to your house. Maybe you should consider having a weekend of celebrating your favorite college or professional football teams. That’s right…a tailgate party! If the weather is in your favor you can cook outdoors, maybe have a small campfire and let some of your family or friends settle in for the night. You can also use your RV as a holiday guest house while friends and family visit you at times like Thanksgiving, Christmas and Easter.
Consider your environment
If you live in colder regions, then I would certainly drain the water system and properly winterize your rig which I have shared in a previous column. However, your RV doesn’t necessarily have to have water for you to use it at home for special occasions during the colder months of the year and in doing so you are also exercising many of these other components and helping them from seizing in the future due to lack of use. The most important thing though is that you are bringing family and friends together and that’s what really matters.
Another thing to consider when maintaining your air conditioning unit or units is to consider where you have been with your RV. For example, parking your RV on the beach at Padre Island, Texas or Daytona, Florida may seem like a good idea, but salt air, sand and dust stirred up by wind and other vehicles can have devastating affects on your AC systems. Another good example of this is people with RVs that attend the annual Burning Man Festival in Nevada during the late summer.
While this is a very popular festival and a popular place to boondock any other time of the year as well, it is in a very arid, dry, hot and windy environment. It can get so windy there at times that the dust becomes so thick that you can’t see 20 feet in front of you when walking around in that area. Also, since the ground in that area is full of alkaline (commonly referred to as playa dust) it has very corrosive quality that can lead to nose bleeds, sinus infections and burn your lungs if ingested too frequently or too deeply. Even the organizers of this event always suggest that attendees wear closed toed shoes because the alkaline in the soil will eventually cause open sores on tissue that is constantly being exposed to this corrosive element.
If this playa dust is so corrosive that it eats away exposed skin, causes respiratory problems and nose bleeds just imagine what it is corroding away in your air conditioning unit that’s filled with aluminum, copper, plastic and steel components while you are camped in an extremely hot desert in August where running your AC is a necessity. Not only will this corrosive dust eat away at your AC components, but since RVs are far from airtight it is likely to be everywhere within your rig if the winds are stirring it up so it’s important that you give your rig a thorough cleaning after exposing it to these conditions.
My RV AC isn’t working. First step: clean it.
For most RVs, the first thing you will need to do is make sure there is no electrical supply to your AC system and then get up on your roof and remove the cowling that covers your AC unit. This task usually requires a Philips head screwdriver and the removal of several screws. Once you have done this, carefully remove the cowling and set it aside with the screws that held it in place. Keep in mind however, that your RVs roof may not be strong enough to hold your weight so it’s a good idea to check the weight restrictions in your RV’s manufacturer guide. In these cases, it may be necessary to access your unit from the side on a ladder or even create a makeshift scaffold using two sturdy heavy-duty step ladders and some solid timber as a platform to work from.
Now is a good time to inspect your unit’s base to make sure that it has a good seal to your rig. Check for dried or cracked sealant and replace as necessary. Once you are sure that your AC unit is properly sealed, I suggest that you take the air compressor that you use to winterize your RV and blow out as much dust and dirt as you can.
Once you have done this, you may want to take a water hose to the unit and lightly spray around its base and even on the components. A very soft bristle brush and a small bucket of soapy water will help you clean the cooling condenser fins, but it’s very important that you treat these as very fragile because they will easily bend. If you bend too many of them, they will inhibit the proper air flow and your AC system will eventually fail.
Stay away from the larger components such as the compressors or capacitors with your brush and water as these may still contain some voltage even though you have disconnected any power supply to your AC system. In fact, capacitors may contain enough voltage to electrocute you if they are not properly discharged and it’s not uncommon for them to carry the charge long after you have shut down the power supply to your AC unit.
I’ve cleaned my AC unit and it’s still not working. What do I do now?
If you’ve cleaned your AC unit out and you’re satisfied that it’s clean enough to operate and it’s still not working correctly, then you need to be a problem solver. The best thing to do here is start small.
Examine your electrical supply
First, examine your electrical supply. If you’re plugging into shore power using your electrical factory supplied hook-ups, are they properly plugged in? Is there a problem with your connection or the campgrounds wiring? Perhaps the campground has an issue with the 50-amp supply, and you may have to plug into a 30-amp receptacle. Always carry an adapter should this happen.
Check for popped circuits
Once you have established that you have a good electrical supply to your RV and its AC unit is still not working, the next step is to make sure that you have no popped circuits in your RVs electrical system. Be sure to check your RVs fuse box to ensure that you have no burned-out fuses and always remember to keep a few packages of those around should you ever blow a fuse on other circuits such as lighting and even things like turn signals and headlights.
Look at your thermostat
If these troubleshooting tips are not getting your AC system working, then the next step is to look at your thermostat. I suggest that you remove your thermostat and check for any loose wiring connections then reconnect the thermostat and reset it according to the manufacturer’s instruction manual. You may even need to use a voltage meter such as the type I referred to in a previous article about the essential tools you may need when RVing to test whether your thermostat is getting a proper power supply and whether it is getting proper continuity. Generally, thermostats are usually inexpensive so something as simple as replacing the thermostat may solve your problem.
I’ve checked everything on the inside and still no AC, what now?
Time to go outside
The next step is to get on your roof and examine the components of you air conditioning unit. Start with the fan motors. Are the blades spinning freely? Is there excessive dust and dirt build up in or around the blades? If the blades on the fan motors seem stiff or are not moving at all, then you will need to either add some machine oil to the tubes on the front or back side of the motors or you may even have to replace the entire motor if that has frozen up on you.
Examine your capacitors
If your AC is not working after these inspections, your next step is to examine your capacitors and I don’t recommend this task to anyone that is not familiar with certain electrical components and how to properly handle them. Capacitors can carry high voltage and can be harmful and even deadly when charged.
However, one sure way to see if your capacitors are bad is to look for unusual coloring or if they are bulging on the ends. If this is the case, then you should remove the wire leads from them and carefully dispose of them properly being very careful to not ground the terminals because of the voltage they may still have stored in them.
Frankly, I recommend changing your capacitors every two years to avoid any future problems with them. As with some parts of your air conditioning system, capacitors are relatively inexpensive and changing them out every now and then may be what’s best for your RV.
Know when to call a professional
If you have done all these tasks and your AC unit is still not working properly, then now is the time to seriously consider having a professional who is knowledgeable of your RV’s cooling system look at your system and even repair it. If the compressor is bad it can be replaced however, the cost is usually prohibitive as a new compressor can cost $400 to $500 while a new air conditioning unit may cost as little as $600 to $800 and that’s with professional installation.
Proper maintenance to any of your RVs components is essential and your air conditioning system should always be a top priority if you are traveling in climates or areas where you may experience periods of uncomfortable heat or humidity. Simple preventative maintenance can save you from a lot of unwanted headaches and uncomfortable times in your rig in the long run.
Remember, keeping your home in good shape is what will make your travels easier and more enjoyable. In my opinion, you can never do too much preventive maintenance and this will always add to more comfortable travels.