2015 Sunset Trail 290QB not cooling well

Bs106 · 07-12-2023, 11:11 AM

Hey all,

I've got a 2015 Sunset Trail 290QB. It's 33 feet with a bunkroom. I am having issues with the unit, it's not cooling well at all during the day. I had a renter show me it wasnt getting below 85. Could this be a thermostat issue? I've gone up and straightened/cleaned the coils as well as made sure the filter is always clean. I also noticed the airflow through the ducts to the bunk room is hardly noticeable. I'm not sure what else to do or check, does anyone have any suggestions or can point me in the right direction? I'm in Key West Florida.

Thanks in advance,
Brett

660catman · 07-12-2023, 11:18 AM

A friend of mine has a 2015 Winnebago fifth wheel. Two years ago his AC was poor so he got a AC guy in to check it. It was low on Freon so he filled it properly. Never had an issue since.

Huskerdude · 07-12-2023, 11:26 AM

We have a 2017 Sunset Trail 310RL. Air conditioner was alright but thought it should be better. Saw a YouTube video on modifying the unit. Took mine apart from the inside the camper and was blown away by the shoddy workmanship.One duct was half covered with roofing material the other one was not sealed up very good. Built the tepee insert and taped up all seams per video and it’s unbelievable how much better is airflow and cooling. Didn’t cost more than $20 . Mike

Bs106 · 07-12-2023, 11:43 AM

Thanks for replies. I understand it's a 33 foot with one AC and very hot temps, but I don't think it should be that hot still. I've heard since they're self contained units that you can't just add freon. You'd need to check amperage and if below 10 the whole thing needs to be replaced. Is this true and how would I test it?

Huskerdude, do you have one or 2 ACs? Do you have a link to that video, was it pretty easy to do yourself? I suspect something similar, but it's been getting worse, last summer it was definitely cooling a lot better. Maybe something with the thermostat? I don't know I've thought maybe its because its so hot that I'd need to install another unit being a 33 ft.

**Lloyd** · 07-12-2023, 11:50 AM

Quote:

Originally Posted by Huskerdude

We have a 2017 Sunset Trail 310RL. Air conditioner was alright but thought it should be better. Saw a YouTube video on modifying the unit. Took mine apart from the inside the camper and was blown away by the shoddy workmanship.One duct was half covered with roofing material the other one was not sealed up very good. Built the tepee insert and taped up all seams per video and it’s unbelievable how much better is airflow and cooling. Didn’t cost more than $20 . Mike

This is more than likely your problem. There are a few threads here on the forum where different ones have addressed the problem the same way with the same results.
Do a little searching and see what you can come up with.

**Lloyd** · 07-12-2023, 12:02 PM

https://www.crossroadsowners.com/for...nts-14074.html

https://www.crossroadsowners.com/for...ork-14042.html

https://www.crossroadsowners.com/for...her-13933.html
Pay attention to the last post on this one.
Good luck.

007matman · 07-12-2023, 12:31 PM

So.. I had the same problem.

I've got a 2015 ST33FR model. It's 38' in overall length.

I did pretty much everything listed here, checked the ducts, fixed some tapping issues, sealed things better, etc.

In the end, I added the second (optional) AC unit. Do you have the dual-zone thermostat and a single AC unit? I'm guessing if you do your camper is also wired for 50A and pre-wired for a second unit.

**mark5w** · 07-12-2023, 12:49 PM

I found out that the duct lines were venting into the ceiling at the end of there run. So I install foam blocks past the last vent in each directions. Plus, when I took off the inside grill, there were gaps that I had to fill with aluminum duck tape so the air went directly to the ductwork and vents.

Bs106 · 07-12-2023, 12:50 PM

Thank you all for the replies, very helpful!

007matman, I believe I do its the RvComfort.ZC thermostat, and there's a slot on the breaker for a 2nd AC unit. And I do use 50amps. Do you know if its fully prewired? Has anyone ever added the 2nd AC unit and did it make a difference/is it worth it?

Lloyd, I checked that last thread and literally have already went through all the suggestions that everyone suggests. Added blacklight UV blocking layers to the skylight vents, keep blinds closed, run several fans, put the awning out to shade that side etc. I keep it on "high cool' at all times so that it doesnt turn off but it still hovers at about 86ish during the day. It's a 15k btu ac.

Robert McAuley · 07-12-2023, 01:06 PM

Your comment "I keep it on "high cool' at all times so that it doesn't turn off but it still hovers at about 86ish during the day." makes me wonder if the unit coils have frozen up. I would shut the AC off for the night and let the coils defrost. Then try again the next day. The AC needs time to cycle off or the coils freeze up, so don't leave it on "high cool". If it's freezing up that's a good indicator you need the second AC unit.

**mark5w** · 07-12-2023, 01:11 PM

That's a good suggestion Robert. Happens to mine when down south.

Bs106 · 07-12-2023, 01:23 PM

That's a good point but when I rent it to people, i can't tell them to turn it off for the night and leave them without ac in 110 degrees heat indexes. I think I'll probably need to install the 2nd ac. Does anyone have any good tips/ suggestions when it comes to this? Is this something really attainable myself or don't bother and how someone to do it?

**dagst1** · 07-12-2023, 01:25 PM

We have had better luck running the fan on high and just letting the compressor cycle off and on. If it needs cool and can not keep up it will run all the time any ways and when the compressor does turn off the fan running helps to move the air and just like running a box fan moving air feels better than no air. Never had one freeze up yet. Works for us here in Mo.

Bs106 · 07-12-2023, 01:44 PM

In my experience it will not stay on despite being much warmer than the set temperature if it's not set to be continuously on.

**dagst1** · 07-12-2023, 02:01 PM

Ours is set to AC cool and Fan ON high. If set to Auto the fan and compressor both turn off and on. Like I stated it works for us your mileage may very.

Huskerdude · 07-12-2023, 05:23 PM

Huskerdude55 here- We only have one a/c unit. It always worked pretty good but after seeing that video on YouTube ,made me wonder. Just search rv a/c mod it’s the one from Why Wait. Love to tinker so this was right up my alley. Took about an hour , fairly easy if you are handy with tools. The change is amazing- I have friends that saw what I did and they modified theirs. Worth the time.

Bs106 · 07-12-2023, 08:18 PM

Quote:

Originally Posted by Huskerdude

Huskerdude55 here- We only have one a/c unit. It always worked pretty good but after seeing that video on YouTube ,made me wonder. Just search rv a/c mod it’s the one from Why Wait. Love to tinker so this was right up my alley. Took about an hour , fairly easy if you are handy with tools. The change is amazing- I have friends that saw what I did and they modified theirs. Worth the time.

Your one ac has always cooled your large rig with no problem before tinkering with it? Has you had it in some 90 degree heat? I'm going to check that out! Thanks for the suggestion

Huskerdude · 07-13-2023, 10:19 AM

Yes , it cooled pretty good unless we had a lot people in the camper,kids and grandkids. We do run a small fan when it gets hot (90’s) outside.When it’s hot outside we make sure we keep the blinds pulled. I never thought I had a problem until I saw that video. Now it cools real good,Mods sure helped !

007matman · 07-13-2023, 11:53 AM

Quote:

Originally Posted by Bs106

Thank you all for the replies, very helpful!

007matman, I believe I do its the RvComfort.ZC thermostat, and there's a slot on the breaker for a 2nd AC unit. And I do use 50amps. Do you know if its fully prewired? Has anyone ever added the 2nd AC unit and did it make a difference/is it worth it?

Lloyd, I checked that last thread and literally have already went through all the suggestions that everyone suggests. Added blacklight UV blocking layers to the skylight vents, keep blinds closed, run several fans, put the awning out to shade that side etc. I keep it on "high cool' at all times so that it doesnt turn off but it still hovers at about 86ish during the day. It's a 15k btu ac.

Sorry I didn't see your reply until now.

My camper had the second breaker installed already, there was a second temperature sensor on the wall in the bunk room (that looked like a useless do-dad but had wiring coming off the back) and next to the ceiling vent there was what looked like an electrical outlet box with just a plain white cover over it. There was a sticker over that indicating that the camper was pre-wired for a second AC unit.

Install was straightforward. I removed the pop-up ceiliing vent and inside shroud. Inside that I ran the wiring from the electrical box through some pre-made holes for the wire to run. Then cleaned up the roof where the vent was at and then placing the new ACunit (a 13.5K mach 3) over the hole. From inside, you use an interior kit (purchased seperately) to clamp the AC unit to the ceiling and secure it in place.

Wiring up the controller was where I ran into issues. The place I purchased the AC unit from sold me the wrong controller. and wouldn't accept a return. I'm assuming that since we have a similar camper, you probably need a 8ooo series controller which is now discontinued. The newer controller is the 9000, but in talking to AirXCel I found out that the 9000 series controller is not compatible with the 8000 series controller that you likely alreay have in the main unit I also wanted to install a heat strip to help a bit in the winter months. My options were to find an older 8000 series unit or upgrade the whole system to a 9000 kit. Doing so would have required new controller in the ceiling for the original AC unit, a new thermostat, and the running of an additional wire. I opted to find one of the 8000 series controllers.

Once I had the correct controller, connections were easy. You have your 120v wiring which is just like residential wiring (Hot, Neutral, Ground), there is a freeze sensor that is pluggged in and the temp sensor connection. If your camper is like mine, it'll look like larger guage 12v wiring. That is from your temp sensor on the wall (you might want to use a meter to validate that it's the same wire). In my camper, the wiring that came off the back of the sensor was tiny. However, somewhere in the wall it transitioned to the larger 12v wire.. I was scratching my head with where that wire was until I checked continuity and realized it was the same wire. Lastly, there were a couple of wires that needed to be connected for the communication to the thermostat.. they look like typical thermostat wiring. However, I think I only used a couple of the wires in there.

There is also a jumper on the controller that you need to change so the system knows that it is the 2nd unit.

The difference this made was huge. My camper cools off in a matter of minutes now even when it's warm out. We live in Georgia, so I think I have a pretty good idea what issues you may face in Florida.

If you have more questions, let me know. This is all recent for me so I may be able to locate part numbers for what I did if you need them.

007matman · 07-13-2023, 12:00 PM

Quote:

Originally Posted by Bs106

That's a good point but when I rent it to people, i can't tell them to turn it off for the night and leave them without ac in 110 degrees heat indexes. I think I'll probably need to install the 2nd ac. Does anyone have any good tips/ suggestions when it comes to this? Is this something really attainable myself or don't bother and how someone to do it?

See my recent post.

in 110 heat, I don't think that one unit is going to cut it.

last year in Missouri, we were in 100 degre temps. the coolest I could get the inside of my camper was 87 during the day.

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