The Best And Easiest To Install RV Camper Trailer Rooftop AC Air Conditioner

Replacing an rooftop A/C is easier than you might think.  Don't pay extra for something you can do yourself in a little over an hour.
Replacing an rooftop A/C is easier than you might think. Don't pay extra for something you can do yourself in a little over an hour. | Source

Getting the Best Deal On the Best RV AC Unit

The rooftop air conditioner in your motor home or camper trailer is one of the most necessary items in your RV. Since the majority of owners use their campers in the summer season, keeping the rooftop unit in tip top working order is a must.

Even assuming you have maintained and repaired your RV AC unit for several years, there comes a time when replacing it is unavoidable. After the unit has a bit of age on it from being used over years of camping seasons, it is often less expensive to just replace the unit instead of having it repaired.

Coleman Rooftop AC-The Best Choice

Easy Coleman AC Installation!
Easy Coleman AC Installation! | Source
A clean surface where the new AC gasket seals against leaks is essential to the installation
A clean surface where the new AC gasket seals against leaks is essential to the installation | Source
Easy ceiling assembly installation.
Easy ceiling assembly installation. | Source

RV AC Replacement Steps

Because replacing the ac unit is normally a very simple job, many RV owners have discovered just how easy and inexpensive installing an air conditioner really is.

Replacement of the air conditioner with a new, and more efficient, unit can take as little as one hour to complete in some cases.

I have replaced and installed many of these units in both motorhomes and travel trailers with most being fairly simple procedures.

This article is intended give you the info needed to not only obtain the best rooftop AC for your particular camper or motorhome, but to get it delivered quickly, and at a great price.

My experience in removing and installing AC units will help you complete the project and keep you cool during your camping vacations.

Please feel free to ask any questions you may have about replacing an old RV AC unit or installing one in a present camper in a new location.

Two units are better than one in some of the larger RVs and motorhomes and more efficient in the bargain.

Any questions you need answered may be posted on the comment section at the bottom of the page.

Finishing the AC Installation Process.

Fitting the flexible connecting duct is a snap with the Coleman AC unit.
Fitting the flexible connecting duct is a snap with the Coleman AC unit. | Source
A couple of wire nuts and a plug-in connection and the electrical connections are done.
A couple of wire nuts and a plug-in connection and the electrical connections are done. | Source
The installation is complete!  See how easy it was!  Be cool!
The installation is complete! See how easy it was! Be cool! | Source

Coleman, The Best Rooftop RV Air Conditioners

Before deciding on the brand or model of rooftop air conditioners, you may wish to see just what replacing your old AC entails. Check out my other AC installation articles which give step by step instructions for the complete process.

This will give you an idea of what to expect, and an idea of any problems you may encounter during the Coleman AC installation.

The Rooftop RV AC unit pictured in the installation is a Coleman 8333 13.5 BTU air conditioner. This model is perhaps the most popular unit for most applications. It comes complete with everything needed including the ceiling assembly.

Every one of these units I am aware of being ordered through the ads on this page was shipped in less than 3 days and arrived in less than a week. My personal favorite of all rooftop AC’s.

Coleman units are now more energy efficient than ever, allowing the use of a bigger unit because of the lesser electrical amperage once needed to run the older AC units.

The Coleman 8335 Mach 15 air conditioner, with its 15,000 BTU cooling performance, is just such a model. This rooftop unit will cool many size RVs whether camper trailer or motorhome. A great unit for big rigs! It's better to have to large a unit than to overwork a smaller one trying to cool a large camper on those hot summer days.

Enjoy The New Coleman RV AC

Once you decide on which model Coleman air conditioner you need, be sure to keep them well maintained by following a season maintenance schedule laid out in my RV AC repair and Maintenance articles linked on this page.

Please feel free to ask any questions you may have in regard to installing your new Coleman rooftop unit, or with any problems you may be experiencing with your present unit.
Coleman units have a great warranty and have a reputation for long lasting and dependable service.

Be sure and use a rooftop unit cover when the camper is not in use. This is very important to the life of the Coleman AC and to the performance of the unit itself. Good luck on your installation.

More by this Author


Comments 51 comments

SteveoMc profile image

SteveoMc 6 years ago from Pacific NorthWest

I was thinking about buying an RV with a bad AC, this helps figure out how much it will take to replace it. Thanks.


Randy Godwin profile image

Randy Godwin 6 years ago from Southern Georgia Author

Good luck with the AC replacement Steve! Thanks for reading and commenting!


Hello, hello, profile image

Hello, hello, 6 years ago from London, UK

This hub is not for me but I will pass it on to my son. It will be more useful to him. Well and clearly written Hub, thank you.


Randy Godwin profile image

Randy Godwin 6 years ago from Southern Georgia Author

Thanks once again, Hello, hello! And I appreciate the nice comments on my hubs!


dallas93444 profile image

dallas93444 6 years ago from Bakersfield, CA

Your "real life" expertise shows! A manual does not replace your hands on knowledge. great hub.


Randy Godwin profile image

Randy Godwin 6 years ago from Southern Georgia Author

I certainly hope you are correct, Dallas! I try to make these how-to RV repair articles easy for owners to understand. Thanks for stopping by!


lightning john profile image

lightning john 6 years ago from Florida

Good information here Randy! I was servicing my 35ft 5th wheel (Honey) a/c once, and right when I was putting the last screw in for the cover(with a power drill), guess what? Yep, right into the freon line.

I sold the R.v. but I sure had some good times with it.


Randy Godwin profile image

Randy Godwin 6 years ago from Southern Georgia Author

I'm sure you weren't the first to do that, LJ! I have made similar blunders but I always learn from them. Thanks


TechnicallyADream profile image

TechnicallyADream 6 years ago

Great hub , with some good info.


Carol from Australia 6 years ago

Hi Randy> We have Coleman Rooftop AC Series 8 or 9000. Water pooling in tray then overflowing back into caravan. Cant find drainage holes to see if they are blocked. Any clues.


Randy Godwin profile image

Randy Godwin 6 years ago from Southern Georgia Author

Hello Carol! I am not familiar with your particular Coleman rooftop AC but most use a similar system for removing the condensation from the unit. While some rooftop AC units use a hole in the chassis for the water to drain down from, most of the newer models simply disperse the water into the air by way of the exhaust fan.

In some cases the accumulated water cannot flow to the area where it can be properly dispersed. Often, simply cleaning the debris, whether it is rust, dirt, leaves, etc. from the bottom of the unit so the moisture may flow to the correct area.

If a drain is utilized by your AC it will be located in the lowest spot on the bottom of the AC unit. Remove any rust, dirt, etc. and probe with a thin flexible wire to open up the drain. Disconnect from power before using either cleaning process. Hope this helps you out!


David Carlson 5 years ago

I have a Duo Therm unit on my 36' Layton trailer. It runs for about 15 minutes the compessor kicks out and the fan continues to run. If I stop and restart it, it will work again for 15 minutes. Any ideas on why it just wont keep working? I have had repair men look at it with little help. Could it be the thermostat?


Randy Godwin profile image

Randy Godwin 5 years ago from Southern Georgia Author

@David Carlson--Although it is possible the thermostat could be malfunctioning, it is highly unlikely it is causing the problem. If the RV ac unit starts right back up after the compressor kicks off by shutting off the unit and then starting it back up immediately, this sounds more like a relay or starting capacitor problem.

I assume the repair men used an amp meter to determine if the compressor was pulling too many amps and therefore tripping the overload. Normally, the compressor will not start up immediately after kicking off.

It is, however, rather easy and inexpensive to replace the thermostat in your particular DuoTherm RV AC unit if you cannot track down the problem and wish to try replacing it. I hope this info helps you in some manner. Thanks for the question and good luck on your repairs.

Randy


Mike 4 years ago

I will be adding an air conditioner to my horse trailer LQ's. Unit is prewired for the unit but would like a step by step on how to install. Looks easy but? Unit is a Mach 5 Coleman w/heat strip.

Thanks, Mike


Randy Godwin profile image

Randy Godwin 4 years ago from Southern Georgia Author

Hi Mike! It should be an easy job if the wiring is already present. If the horse trailer already has a 14x14 inch vent hole then you are good to go. Otherwise, cutting the hole will be the hardest part of the A/C installation.

If you need further advice feel free to ask and I'll be glad to assist you with any problems you may encounter. Thanks for visiting my site and for the comments.

Randy


Mike 4 years ago

Randy, thanks for reply. Hole and bracing is all set for unit. Original owner opted to not add the air at time of conversion. Hope to get at it this WE.

Mike


Randy Godwin profile image

Randy Godwin 4 years ago from Southern Georgia Author

Great, Mike! You should have a very easy installation with no problems as everything seems to be ready for the new rooftop unit. I've installed quite a few Coleman Mach 5 units and they are very easy to replace or install new.

Good luck on your installation and let me know how it comes out.

Randy


Mike 4 years ago

Randy, do you know if the AC comes with the gasket to install or did I need to order that separate?

Mike


Randy Godwin profile image

Randy Godwin 4 years ago from Southern Georgia Author

Yes Mike, the new AC should come with a complete installation kit, including all gaskets and screws for the exterior mounting and for the ceiling assembly.

Randy


Mike 4 years ago

Randy, I installed AC this WE and there was only instructions on operation of the AC and install of heat strip in box. Thanks for the pictures and COMPLETE instructions in this forum. Had difficulty with supplier as I ordered unit first part of March. I unwrapped unit on Thursday of the past week and noticed that the shipping frame was damaged. After unbanding and removing shrouds I noticed the frame of the AC was bent and fan was tight against the shroud. Supplier said I waited too long and so sad. I was able to straighten the frame and got everything working. Guess I learned a lesson when I order to inspect ASAP not when I am ready to install. All came out good after I got over the frustration and again thanks for the help--it made the install easier.

Mike


Randy Godwin profile image

Randy Godwin 4 years ago from Southern Georgia Author

Sorry you had a damaged unit, Mike! It is a good idea to check for damage as soon as the unit arrives. I've had the same thing happen with house units. Often the box will look fine but when unpacked, the unit can be bent from rough handling during transport.

At least it wasn't beyond repair or use. I'm pleased my article helped you in the installation process. Thanks again for your comments and time.

Randy


mudbug001 4 years ago

I have a 2004 Alumascape 32 skd 5th wheel. I want to add a second a/c in the bedroom. There is a powered roof vent there now and the trailer is wired for 50 amps. Do you know if these units are prewired for the second unit there?


Randy Godwin profile image

Randy Godwin 4 years ago from Southern Georgia Author

Hey, Mudbug! There is a possibility of your RV having already being wired for the second unit because most 2 A/C equipped RV's require such a large amp supply to run both units.

I can't say positively though. I'm not familiar with your particular camper. If there is a pre-wired connection point, it should be readily apparent when you remove the powered vent for the new installation. The vent is already the correct size to fit the new rooftop AC unit.

Even if you have to run a new wire it still is no big deal other than secreting the wire where it is not too visible. Hope this helps!

Randy


barry 3 years ago

how much of an angle can you put a roof top coleman at. and it will still work?


Randy Godwin profile image

Randy Godwin 3 years ago from Southern Georgia Author

Hello Barry. The unit should work with slight angle on it but there comes a point when the moisture may collect and start leaking out of the bottom of the unit and running off the roof of the RV. I'd suggest temporarily trying the angle you want and running it for a bit to see if it works satisfactorily. Hope this helps!

RG


carolyn 3 years ago

we are ordering a coleman mach 15000 from ppl but they say the ceiling assessmby is not included, is it possible to use our old ceiling assembly and not replace it with a new one , we have ducted ac./ our present inside a/c grill/cover does not have any wires in it, can you please comment. thanks


Randy Godwin profile image

Randy Godwin 3 years ago from Southern Georgia Author

Hello Carolyn. I doubt your old ceiling assembly will be compatible with the new one. I recommend ordering the complete unit to avoid problems.


C J Gurr 2 years ago

Randy, we purchased a 1966 vintage trailer...no air conditioning. Would it be possible to put a roof air conditioner in the unit?

Thank you, C J


Randy Godwin profile image

Randy Godwin 2 years ago from Southern Georgia Author

Hi CJ! Yes, if the roof is strong enough to support a roof unit it should be rather easy to install. A roof A/C uses a a standard 14" X 14" roof vent which you probably already have in your vintage trailer.

Let me know if you need any assistance with your installation. Thanks for the question and your time reading my articles.

Randy


Ken 2 years ago

If I replace my ac unit with a different name and the wire colors don't match what should i do


Randy Godwin profile image

Randy Godwin 2 years ago from Southern Georgia Author

Hi Ken, I assume you're talking about the thermostat wires as the power wires should be the same color. Am I correct in my assumption?

Randy


Joe V 2 years ago

The hole in my roof of horse trailer is approx 26x26. What are my options if any other than resizing hole?


Randy Godwin profile image

Randy Godwin 2 years ago from Southern Georgia Author

Hey Joe, there may be an adapter although I haven't heard of a vent or AC hole that big. Resizing may be your only alternative.

Randy


ray 2 years ago

i have a 2002 dutchmen sport, the ac will freeze up on the condenser and i have to turn it off and wait for it to defrost. what could be wrong?


Randy Godwin profile image

Randy Godwin 2 years ago from Southern Georgia Author

Hello Ray, several things can cause your AC to freeze up in the manner you've described. Running the thermostat too low--by low I mean the temperature setting--causing the unit to run constantly and icing up the coil. Another problem may be having dirty evaporator or condenser coils and therefore inhibiting airflow enough to cause icing. One other cause is having a low freon charge in your AC. Not long before the freon leaks out entirely the unit will blow ultra cold air and the result is an iced up coil. I hope the latter problem isn't true of your unit as the first two causes are simple fixes.

Randy


Bryan 2 years ago

My brisk-aire duo-therm a/c the fan is now runing in reverse


Randy Godwin profile image

Randy Godwin 2 years ago from Southern Georgia Author

Have you recently done any repairs on your AC, Bryan? Is it a ducted system by any chance?

RG


Sweaty Carrie 2 years ago

Our ac is out on our 1992 motorhome. It is a coleman 6757 or 6759. We were told the compressor has seized and we cannot repair it, so I am looking into new units. At camping world they said that the new unit would work with the old ceiling assembly. Another dealer said because it is so old the ceiling assembly will not work with the new unit. Is there some way to know for sure, because even at a hundred bucks, savings right now are super necessary...


Randy Godwin profile image

Randy Godwin 2 years ago from Southern Georgia Author

Hi Sweaty Carrie, you may be able to get an AC with the ceiling assembly included for less than the cost of one at Camping world. Or you may find what you need on this page:

http://www.amazon.com/s?ie=UTF8&field-keywords=RV%...

Or check out the prices on new AC's here:

http://www.amazon.com/Advent-Conditioner-Std-Ducte...

Sorry I can't advise you as to whether your old CA will fit a newer model as I don't have the specs on yours.

Randy


Ted Breen 2 years ago

Hi Randy,

I have a Coleman unit in my 1990 at it has started leaking when it rains

What do you suggest?

Thanks in advance Ted tedind@msn.com


Randy Godwin profile image

Randy Godwin 2 years ago from Southern Georgia Author

Hi Ted, you may be able to tighten the bolts which compresses the gasket underneath the ceiling assembly to stop the leak. If this doesn't work then you need to install a new gasket beneath the AC unit. It isn't a difficult job as you can tell by the photos in this article. I hope this info helps you solve the problem. :)

Randy


Devin Sibo 18 months ago

Have a 1974 33 ft fith wheel a/c worked. Restoring it first camper just would like to know best location for a a/c unit. It was in the tallest part of trailer in middle butt was going to change the roof pitch to a nice slope instead of dteep pitch and then last 10 ft is flat. Guess question is wat is best pitch for a/c and best location?


Randy Godwin profile image

Randy Godwin 18 months ago from Southern Georgia Author

Hey Devin, The closer you put the unit to the middle of the camper the better it will cool it overall. You'll have to construct a minor offset to mount it level, of course.

Sorry for the delay in responding but there's been a death in the family. ask for more info if needed. :)

Randy


jeff 17 months ago

where is the best place to buy a new coleman?


Randy Godwin profile image

Randy Godwin 17 months ago from Southern Georgia Author

Amazon or Ebay will normally have the best prices and fastest delivery, Jeff. :)


Patty 16 months ago

Hi, We need to put in second air conditioner in 2008 keystone Everest 305T Does it have to be a low profile AC?


Randy Godwin profile image

Randy Godwin 16 months ago from Southern Georgia Author

Hi Patty, not at all unless you are concerned with low branches or other obstacles. Usually there are only a few inches difference in height between a low profile and standard rooftop AC unit.


George 15 months ago

Randy, any experience in using a Coleman 15000 to replace a Carrier Air V using the Coleman adapter kit. The Carrier I have is a Ducted Heat Pump, so do I have to use a Coleman hit pump to use my ceiling assembly?


Randy Godwin profile image

Randy Godwin 15 months ago from Southern Georgia Author

Sorry George, I've no experience in adapting a Coleman A/C to a Carrier ducted system. It shouldn't be very difficult with the correct adapter kit.

Randy


Wanda Rhiner 5 months ago

Hi Randy,

Enjoy all the great articles! We have a 2012 Aspen Trail TT and water continues to go into the fresh water tank without us putting water in it. We have never used the fresh water tank, never put water in it but anytime we go camping, water gets in the tank. We had the local dealership "fix" it but we just found out over the weekend, they didn't fix the problem. Any ideas how water can be getting in there and how we can stop it?

Thanks!


Randy Godwin profile image

Randy Godwin 5 months ago from Southern Georgia Author

I don't know about your camper Wanda, but some have a fresh water tank which always fills when you hook it up to a fresh water connection. It should be a simple matter to bypass the tank altogether and I'm assuming this was what you wanted the dealership to do before. If you paid them to fix the problem then I'd either ask for my money back or for them to refix the "fix."

Randy

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