Foretravel Owners' Forum

Well, after 18 years of use, the Dometic Duo-therm AC's were definitely in need of replacement. Last fall, while at an RV Park in Destin, FL on our way back from Glacier NP we lost the front AC due to very low voltage, it smoked and gave up the ghost...

We used the Coach extensively this spring and summer in the Northeast, mostly in Maine. One AC, the rear worked OK for us. Although, you could tell it was struggling to keep us cool, getting louder, lots of condensation... Once Covid hit, supply chain issues, it was nearly impossible to get any of the Dometic AC units. Couldn't find any Atwood's either. My instinct was to simply replace the units with the Dometic low profile Penquin II units.

I investigated the Furrion Chill AC's, and was very intrigued with their so called "soft start capacity" as we do spend time in our families driveways... Would be nice to run ONE air conditioner on a 15 amp plug. Kept hearing that the Furrion Chill units were also quiet, a TOP requirement that we had. There were concerns about the difficulty of switching from Dometic to Furrion and they were the following:
1.   Furrion System documentation was incomplete in many ways, trying to find a concise end-to-end document was a struggle.
2.   Tech Support calls to Furrion were at first, odd... More like simple sales support. Did not leave me with a good feeling, staff didn't or couldn't get into much detail...
3.   Didn't see any decent write-ups on our Forum or other Forums regarding end-to-end installations and successes with the Furrion units, (like integrating with Aqua hot or our existing wiring verses Furrion controls).
4.   Spoke to one Foretravel owner whom did not have a good experience, (installer issue).


Two weeks ago, knew I had to fix my problem with the AC's, because we were headed further South to Fort Myers and Naples for Thanksgiving and December.  Called a bunch of distributors, NO stock, no AC's, wasn't going to be a happy trip... Looked again at the Furrion Chill 15.5, they were available and in stock.

With some help from John Morales who took me through his Dometic install, regarding what wires were up in the roof, and a quick call to Rudy on the Aqua hot side, and a consult with Ron Riensche (redtractor) - it sounded like the Furrion AC's might work. I contacted Furrion again and BINGO, got the correct Technical Support person, finally! Talked through the Thermostat to Furrion Control unit connections, plus call for heat and control power requirements with a Furrion Engineer... Sounded to me like I could make it work with what we had for wiring in our Foretravel U320, EXCEPT FOR THE REAR AC POWER... But an easy fix was possible.

Install Observations:
Took me three days to install the units.  Half a day painting... Literally spent a day cleaning up the roof top openings to make the space more efficient. The old foil tape was falling apart, ducts needed some attention,  some holes were unsealed, and the end result looks really good, and likely quieter airflow too. Then spent a few hours tracing / verified wires and confirming power.

Taking the old units off went smoothly, four bolts and they were loose. Recommendation on tightening down the four bolts: Instructions say to tighten the four bolts between 40 – 50 FT POUNDS. I found via a couple of You tube video, better to compress the foam to about ½" – 9/16", go onto roof, make sure all sides are compressed equally. Our roofs have a nice curvature... Next,  CLEARLY  -labeled all wires and then cut the wires on the inside, (of course- turn both AC and DC power off first). Cleaned the top surface under the AC units. Don't use any addition sealant, Furrion has a nice robust seal. I scrapped out the motors and squirrel cages from the Dometics, (reduced weight) which made sliding them off the roof, down a ladder against the rear cap very easy. Next, re-packaged the Furrions and pushed them up the ladder onto the roof. Took two of us, one pushed, one pulled, but not as hard as I thought it was going to be. Get then close, very easy to fine adjust from the inside.

Next tackled the wiring:
First- took care of the thermostat wires. I struggled at first thinking I would re-use the RJ-11 connectors that were in place, however it just didn't make any sense. So, clipped off the component ends. Luckily Foretravel used 6 wire flat phone connector cable, the wire size was decent for telco. The critical control circuits for Furrion; require FOUR wires. These need to travel from the Thermostat to first AC, them to second AC. The four wires carry: #1- +12V, #2- ground, #3 Control A, #4 Control B.  Very simple. Minimal draw for the 12 volt lines, they power the thermostat and some control card aspects at the AC end.  To be safe I piggy-backed the two unused wires onto #1- 12V and #2- ground.  These were connected at the thermostat, then daisy chained to AC #1 and then daisy chained to AC #2 via existing wire in the roof.  At the thermostat end I tinned and soldered the wires, then used small ferrule pins, crimping them on to make it easier to slip wires into the Furrion thermostat connection block.

The Furrion Chill units ALSO require a separate 12 volt line to power the Control units. In our Foretravel's, the first AC has a dedicated 12volt line, so simply used that, and connected to the Furrion DC power wires. Next, connect the 120 volt AC wires, (3) into the control unit. To keep things neat, I removed the six analog wires from the Furrion control unit, (simply pull the connector, remove the wiring harness- these are "analog control wires - not used for any purpose). You will also find one existing 14 gauge WHITE wire in the roof at each old AC unit, which is your call for heat wire to the Aqua hot, (turns baseboard blowers on). It should have +12v on it with NO CALL FOR HEAT. Verify this by checking in the Aqua hot control box in the basement, top terminal strip. It's labeled, Living Room, Bathroom, Bedroom...  I removed the wire at the terminal block, verified there was NO voltage back up top.  By the way, to test your blowers and turn on, simply connect a ground to this +12 line, blowers WILL RUN, (closes contact for blower power at Aqua hot). This verified for me that the Furrion control units would work in the Foretravel setup. Furrion uses a simple normally open relay to CALL FOR HEAT based on the Thermostat setting and the thermo-couple reading in the Furrion AC Control Box. .  So, to hook this up to the Furrion and integrate into our Aqua hot:  Furrion has two BROWN wires from the control unit, connect one to the white 14 gauge Aqua hot wire, connect the other BROWN wire to the ceiling framework ground screw, (not polarity sensitive).  Also, Furrion has a thermo-couple that hangs down in the air distribution box to sense room air, used this sensor for the front AC.  We will be using the existing Bedroom thermo-couple (small white wire pair with connector) for the REAR AC. Simply save your female connector from the old Dometic and splice into the Furrion line. We verified that the heat does turn-on by using an ice cube to cool the thermo-couple, it works, Aqua hot blowers turn on.

Now the one issue you will find is there is NO 12 volt line to the rear AC to power the Furrion control unit. Easy way to fix this is to tap off the 12 volt line that runs behind the ceiling light in front of the shower, it feeds the bedroom lights. I took down the light, you will find a ½" conduit that passes the flat RJ12 communication line from the front AC back to the rear of the coach, with lots of room for one 14 gauge conductor. I also wired in a 3 amp fuse block between the spliced line and the Furrion control unit, (to rear AC) just to be safe.
 
All Coach control and power wiring should now be installed. Plug control unit connector from upper AC units. You will need to plug the freeze sensor into the evaporator coil, connect it to control unit, make sure the plastic grabs the evaporator tubes, (will fall out if not engaged).... You should be done with the wiring.

Once the thermostat sees 12 volts it will begin to provide a readout. You will know if all is well, no error codes. Time to test.  We started the generator, as we are only connected to a 15 amp AC plug, 100' away... Fan modes worked well, AC worked well, compressor was quiet and blew COLD air, Turned heat on, used an ice cube to chill down the thermo-couple, AND the Aqua hot blowers worked !!!

Now, took another couple of hours to clean everything up, neaten up the wiring, etc. and put on the covers, filters and diffuser in place. The only drawback was that the bathroom closet door doesn't clear the Furrion diffuser. A minor issue.
Next. We tried running ONE AC on the 15 amp AC circuit we were attached to. Worked great, did not blow the circuit breaker. I'll test tomorrow further, not sure what, if any the Victron contributed from the Battleborn's to the energy demand.

Conclusions:
How's it sound? Well, antidotally it's a lot quieter than the OLD Dometics!  The fan will run continuously as long as the AC is switched on. It does work in automatic mode, shifting down to low speed which is very quiet. Cannot tell its running from the outside.  I'll add some decibel readings later.

How does it look? Well, it's about 3.5" taller on the outside. Definitely not low profile, however I don't think it looks terrible...
No Heat Pump, however, we never used it when we had it, prefer to use the baseboard Aqua hot heating.

Again our goal was to replace 18 year old AC technology, which was VERY loud. We wanted quiet replacements that were energy efficient. Furrion reviews suggested this was the case.  Sunday Kristen and I will depart for three weeks and will thoroughly test these two AC's out. We'll let you know our thoughts...

Hope this helps others who might be looking for alternatives to the Dometic AC's. Glad to finally contribute something technical to al that have helped us on our Foretravel journey !!!

Jeff & Kristen

Forgot the final photo of the roof...  :))

So these are non-ducted units, correct?  All airflow comes out the unit itself, rather than pushing through the plenums in the ceiling to the FT-installed ceiling ducts?

Sideview of the Coach.

The units are Ducted. Attached is a photo of the condition of the ducts, they were a little tattered prior to cleaning everythin up and sealing with aluminum tape.

Jeff

First class technical project writeup, Jeff.  Well done!  ^.^d

This is the kind of post that really adds value to our Forum.  By taking the time to go into detail about what work was required, plus adding the clear photos, you will be a BIG help to anyone else contemplating the purchase of this brand air conditioner. 

Awesome write up Jeff and a nice review of these Furrion units!  We have looked at these as well.  Hmmm!

A great write up. I know it took you some time to document this but you have really blazed the trail for the next wagon train. Thank you.

Thanks for the complements folks!  I'm way overdue contributing to this great forum. I'm gained a lot  from the many experts here!

Glad to have a Foretravel, even better to have this Forum!

Jeff

Nice writeup.  My A/Cs are original also and I'm afraid are about at the end of life so I'm researching what to replace them with. We try to stay where it is cool so not using them much in the summer other than getting across Texas. Quiet is very important and these seem to deliver that requirement.
I saw recently that GE has come out with a rooftop AC also.
I emailed Dometic recently and asked if they will continue to produce the Atwood A/Cs and they said yes but didn't give any other info as to whether they have changed the design or not. So after stock gets back up they may be available again. Only took 3 emails asking the same question to get that answer.
I'll definitely keep Furrion on my short list.
BTW what did you paint the covers with?  Looks really nice.

Did you use the multi thermostat or 2 singles?

Received this information in a email ad today.
Its a 15,000 btu heat pump roof Ac unit by GE. I know nothing about the unit. GE was mentioned in writeup or reply. Figured I would share information.
Vr Mark

General Electric ARH15AACB RV Air Conditioner With Heat Pump - 15,000 BTU -... (https://www.rvupgradestore.com/ARH15AACB-GE-RV-Air-Conditioner-p/arh15aacb.htm)


Black or white same price

Thanks for the writeup and not having a heat-pump is better. I like things simple, I never use the heat pump, heating from the ceiling
makes no sense.

Forest-  Yes I did paint the covers. When we picked up the coach the AC covers were painted by Extreme to match the Gold paint in the Foretravel scheme.  The Dometic AC covers were so brittle that we eventually lost one on I-10 somewhere... So I replaced both with the standard white, never liked the match, just didn't "fit" the finish... I think "paint-matching" he covers to the coach colors makes these units stand out a little less than the brilliant WHITE that they have, not bad...  The black on the bottom is the original.    So, actually went to Lowes and picked up 4 cans of Krylon Gold metallic for plastic and several cans of clear coat.  Matches OK, but it's a terrible terrible paint job by my standards, you just can't get strong coverage with cans on the porous plastic material...  I need a small paint spraying set-up...

I used the Furrion Multi-zone Thermostat, it will control up to four zones. It's a little larger than our "old" Dometic Thermostats, but much more modern.  I'd love to find a more modern look for the bathroom thermostat. 

Here's picture of what the Furrion's look like out of the box.  Furrion has a very cost effective "bundle" if you purchase the two Furrion Chill AC units, plus multi-zone control units (one for each AC), Air Distribution box, and the Multi-Zone Thermostat.

Best, Jeff

Yep-  Never could get used to hot air blowing down on me.  Isn't heat supposed to rise?  Growing up in the North, we always had hydronic baseboard heat, so much more comfortable! 

Jeff

Nice clear, informative  write up Jeff.
Well done.
JohnH

Nice job Jeff,

A couple questions ...

How much does the inside air distribution assembly hang down from the ceiling?  Some of us taller folks want to avoid low clearance issues.

What operates your Aqua Hot? 

Where are the front and rear AC temperatures sensed?

Did you post a source?

Thanks

Roger

Hi Roger-  I too was concerned about the width dimension of the Furrion air distribution cover, based on the sales material. The dimension is 1-1/2" from ceiling .  I knew it would be a problem in that rear hallway between the closet and shower. In the first post, last photo you can see I "almost" made the clearance between the split-door hinge. The door opens enough to get stuff in/out.

FYI- In their distribution cover options Furrion also provides a more expensive cover with four color LED's (12v) controlled by the thermostat. I purchased the simple non LED cover... However, looking at the schematic and the connector in the control unit, everything is up there! At some later point you could install small 12v LED strips... Perhaps push a four wire flat cable left and right to the two ceiling recesses and change those amber lights to RBG LEDs ? Would be cool!


Aqua hot blowers are turned on by "grounding" the one white 14 Guage wire in the AC  distribution box area  coming up from the AH terminal strip behind the AH cover in our basement. The terminal strip is clearly marked identifying the rooms/zones. The Furrion engineer said their "furnace control" is a simple N/O relay, contact, the points close when the  thermostat is set to Heat or Automatic AND the temp therm-couple at the Control Unit, (two screws attach control unit to bottom of air distribution box, warm air return) senses a match for the desired temp. There are two brown wires from control unit marked "FURNACE". So, to check, and verify operation: I measured both continuity and any potential on either conductor. Zero, at NO HEAT so assumed this was as stated, a simple N/O relay point. Then set the thermostat, used an ice cube on the thermo-couple, watched temp go down on the thermostat and at the set point, the relay closed in the control unit, now had a connection through the relay. At this point I knew this operated exactly like Dometic's implementation. Simply connect one Brown wire (furnace) from control unit to ground, other brown wire to the white lead coming from the AH. Works as designed, turns blowers on. As most all of us know, the actual HEAT part is separate and is turned on via switches in the kitchen, (electric, diesel, or engine).

Temp Sensing: In the Furrion control unit that gets mounted within the warm air return is a small black therm-couple sensor on about a 12" lead. This hangs directly in the middle of the box, sensing room air being pulled up through the unit. It connects to the control unit board via a connector. There is a cover on the control unit to access the inside as you need to set addressing (zone 1 or zone 2). In the front, I left this as is, (same as Dometictic). In the rear, I had several conversations with AC guys, who felt that these thermo-couples are basically all the same...

So, my plan for the rear air is this: I would like to use the bedroom temp sensor under the TV at the foot of the bed, for better accuracy. I left the small white two conductor plug for the bedroom thermo-couple taped to the sidewall of the air distribution box. I did not hook this up yet, using the stock Furrion therm-couple at present. I did keep the other end of the white connector so I could plug/play. I want to get several days of living with this AC setup and understand how it cools the bedroom via the ducts. I'll use a separate temp sensor to monitor... I'll compare the impedence of the two sensors, and if close swap them out and see how that works. I expect there will be a slight variation on how the the Multi-zone thermostat reads the Dometic Sensor...

I sourced these through Etrailer.com, they seemed to have the best price, free shipping, and were recieved in three days.
https://www.etrailer.com/RV-Air-Conditioners/Furrion/F15ZA12SAZA-W.html
 
It was a fun project, very DIY project, just get some help with hoisting on/off the AC's on the roof. It went quicker than expected and provides another option for AC replacement.

Best, Jeff

Seems like several of the 'new' roof air conditioners do not turn off air moving fan, and stay running on low speed until cooling is called for.  This feature has benefits for keeping air moving, but seems like something I would rather not have.

We have found it easy to run wires between both roof air conditioners by routing them through roof air duct.  We now have a switch option to control rear air from front temp sensor, front air from bedroom temp sensor & both roof air to control from front sensor or normal, by using air duct to round a wire.

Beeman,

Totally irrelevant question,

Nothing to do with the technical problems you faced:

But I have never encountered the phrase " .. giving up the ghost ..." in English  outside the literal translation from German when something failed " ... den Geist aufgeben.."

Just curious

Regards

Klaus

Regards

Klaus

Mind showing us how you did this Barry?  We frequently run the rear air when we watch tv in the front.

giving up the ghost refers to something that finally  does not work and needs to be thrown out.
Johnh

Forest & Cindy,

To control our rear A/C there is a small wire connector just above the input filter that connects to the bedroom wall temp sensor.

To control our front A/C that wire in the front roof air does not have any temp sensor connected and both control boards are designed to use the temp sensor built-in to the front wall mounted Comfort Control.

So, if you put a switch or unplug the bedroom temp sensor plug in the rear A/C, that unit will automatically default to be controlled the front Comfort Control temp sensor.

Let us know if this is not clear after looking at your wires above the air filter.

Barry

Thanks Barry, that just went to the top of my winter projects!

Now to control the front roof air with the existing bedroom temp sensor, with a switch connect the unused front plug to the same wires in the rear roof air, running a pair of wires up in the air duct. This will use the bedroom temp sensor for both roof air conditioners.

We used a DPDT switch at the rear A/C, and I will find my wiring diagram if needed.

Barry

Found more info on our roof air modifications:


Rear AC ? (http://www.foreforums.com/index.php?topic=25034.msg197484#msg197484)

Duo Therm help needed (http://www.foreforums.com/index.php?topic=24485.msg191820#msg191820)

Improved our coach cooling with both roof A/C synchronized (http://www.foreforums.com/index.php?topic=18764.msg129840#msg129840)

Barry's third link leads to dead end.

See
Improved our coach cooling with both roof A/C synchronized (http://www.foreforums.com/index.php?topic=18764.msg129840#msg129840)

Were there pictures?

Roger

Hi- Sorry for the delay, headed South a bit on Sunday for the next several weeks enjoying the beach at at the Red Cocunut RV Park.

Klaus, John -  Interesting, never knew that phrase to be of German decent, however I believe I picked that up from my German Grandfather, who was a Machinist by trade. Now it all makes sense!  Your definition is exactly as I remember John...

Barry - That's a nice trick switching AC thermo-coupler sensors. Yes, the rear AC has a small two wire connector, (white wires) you will find up in the air distribution box, coming from the bedroom sensor. The 1/2" plastic conduits in the ceiling make running wire easy between front and rear.

Since arriving here at the beach Sunday afternoon we've had a couple hot days to try these units out.  They work well, they are quieter than the old Domoetics. You can barely perceive the compressor switching on or off. We kinda like the constant fan. It does move air, as well as provide a "white noise effect", not objectionable.

Found we like the front AC on during the day, cools the coach well. At night switch to the rear, the Furrion Air Distribution box has North/ South vents. On the rear AC we close the front vent, the majority of air flows strongly and directly into the bedroom door plus via the ceiling vents. Cools the.bedroom nice. We also noticed that the air volume is much stronger than the Dometics, so in the evening watching TV, we get cool air from the front ceiling vents up front pushed from the rear AC, with no overhead noise. We definately like that operation a lot!

I will likely replace the Furrion Air Distribution Box thermo-couple and move it to the bedroom location, see if it makes any difference. So, far, no issues with the sensing of temp or comfort, just curious...

Happy Thanksgiving. 

Jeff & Kristen

Jeff

Hi Jeff,

just fyi. I followed your outline on this post and just completed this project on my coach.  The temp sensors are NTC (negative temp coefficient) thermistors. Thermistors work off resistance. I checked the resistance of the Furrion thermistor and the old Dometic thermistor in the bedroom. At 77f the Dometic thermistor is reading 7k ohms while the Furrion was 10k. I considered adding a resistor to the Dometic thermistor to match the Furrion resistance.

In the end, I just removed the Furrion thermistor at the control box and spliced in the old Dometic plug. Then I spliced the Furrion thermistor in place of the old Demotic thermistor in the bedroom. It works really well.

Due to a short cycling (compressor continuously engaging and disengaging) in the front unit, I had to play with the placement of the thermistor on the front unit. Eventually I found a spot that stopped the unit from short cycling. I wish furrion used the thermostat for the sensing point on one of the zones or at least gave you the option.

This was a great write up and I appreciate you blazing the trail. I am still trying to get my Aquahot blowers to engage when the wire is grounded, but I will get that sorted out eventually. I also have to take about 1/8" off the bathroom door to clear the ceiling distribution box. I have all summer. :-).

Hi Rex, Glad it worked out. We like the Furions too.

We've noticed an added benefit in that the Furion's have much stronger air velocity output than the origanal Dometics. So, we've gotten into the habit of running the front AC only at night with the front vents closed. This pushes cool air out the rear ceiling vents in the bedroom.

I also removed the lamp fixture on the wall in the bedroom where the mirored cabinet is and installed two 12v boat fans, (Carfano Sirocco II swivel fans) in its place.  They can be infinitely adjusted, then tucked away against the wall when not in use. Works great, adds a little better airflow, and very comfortable and quiet... Note, unfortunately we don't have a ceiling fan in the bedroom.

The Auqua hot connection should be easy, each AC opening has the Aquahot "turn-on wire" up there. Simply touch it, (ground it) to the aluminum frame rail up in the roof cavity. This should turn on your Aquahot blowers. Rudy gave me that tip,, (thanks again Rudy!). Then simply find the Furrion control wire to the Normally Open relay. Connect to AH, ground the other side and done. When the thermostatstat "calls" for heat, the Furion Control unit in each  AC unit close that NO contact and turns on your AH. There's two contact points in that control unit card, use the NO one...

Yeah, I had similar cycling issues, but moving the thermistor around cured it. Also had the closet door issues, a minor problem...

Two issues I want to fix this summer:  I want to see if I can find a paint that will adhere to the air defusers which matches a little better to our ceiling verses the stark white... Also, I want to try to somehow backlight the thermostat, or I'll add a small LED to illuminate it, at night it's hard to read...

Best, Jeff

So just to understand the ducted version also has vents on the inside cover?  You just keep these vents closed in order for the air to be sent through the ducts?
For the Aquahot are you using the Furrion thermostat to control that temp?  Or a different thermostat for the front and bedroom?
Thanks!

Jeff great write up.
2019 I installed 2 Atwood's in my coach. I could not get the aqua hot to work with them. Both Rudy and David in Las Vegas tried to help but couldn't make it work. Tried calling their tech support but no bueno. So what I finally did was get a couple of the Atwood manual thermostats ran wires down to the aqua hot relays. Now I have three manual thermostats one in the bedroom one in the living room and one in the bathroom. Well it can be a bit inconvenient I can have heat in one or the other both are all three depending on how I want it. I also run the rear AC independent of the front with a separate thermostat that I installed in the bedroom. I like it that way. Also my friend AC unit has a soft start on it and can run off my lithium battery setup and solar great for going down the road when you have an issues with the generator LOL but only in full sun. I did not put a soft start on the rear but I'm either hooked up to shore power or the generator and it's not an issue. I tried everything to get the thermostat to work with the aqua hot but didn't try the ice cube trick maybe that was it. But I like the way it is now in I can sit on a jackknife sofa and control the heat without really even moving. I think also that the atwoods are quieter than the old dometics, push more air, they do have the heat pump function which I like when the temperature is between 45 and 60° outside. Under 45 it doesn't work as well and then I use the aqua hot. Well I did like the low profile of the dometics it's not a big deal.

That's correct forest. The ducts distributed to cold air throughout the coach but you can still open at least on the atwoods two slides that will blast air right down from the inside unit.
And from what I read on his original post he is using the furry-on thermostat to control the temperatures with the rear temperature being controlled or monitored by the temp probe in the bedroom.
At least that's how I read it.

Hi, sorry for the delay here. been real busy this week trying to get packed for our 2021 adventures... Heading North tomorrow afternoon, to New England for Mothers Day to spend some time "driveway surfing" with the kids and grand kids. Then on to Lake Champlain, Vermont for the summer... Also, trying to get all my Solar upgrades completed before I don't have access to my big tools...Think I'm done, as of tonight ! Horay!

About the Furrion AC's:
They operate very similar to the Dometic AC's as far as control logic. You obviously need to change to a Furrion thermostat, simple transition. The Furrion AC units have thermo-couple sensors up in the air box to measure the temperature. They also have a control card in the AC unit that communicates to the thermostat, over by the drives seat. That thermostat simply sets up the conditions for the control card, (in each AC) to react to the settings. In the front AC, I simply used the Furrion thermo-couple to detect and control the cooling and control the Aquahot. In the rear, I wired in (removed / replaced) Furrion thermo-couple and used the bedroom Dometic temp sensor below the TV. Yes, the resistant/impedance is  a little off... It still works fine,

The Aquahot fans are controlled by a simple "grounding" of the Aquahot control wire found up in the AC opening. Furrion supplies both a normally open, and a normally closed relay in their control card. wire the Aquahot line to the NO relay, ground the other side, simple!   

Airflow: Indeed, you CAN get decent COOL air front or back from one AC if you have a good powerful blower and unobstructed ducts! It was a welcome surprise for us !!!  The Furrion's do have more air flow power than our original Dometics, IMO. However the 14" x 14" ducts were a mess... Lots of obstructions, wires, junk. I cleaned these up during retrofit and made the air ducts as streamlined as possible. It does make a huge difference! I think I posted before and after pics in my original post. YES. the Furrion air-distribution box has "shutters" that you can completely close to force air strictly into the ducts.

I purchased the Furrion's simply because we could not get the Dometics at the time. We already had a "broke" front AC, didn't want to risk chance last year leaving with only one 19 year old AC working... I Iiked the low profile of the Dometic's a lot. I also like the price point and operation since owning/installing the Furrion's.

Best, Jeff 

I just completed the Furrion upgrade, two air conditioners and thermostat, and I have some notes to add.  This seems the best place for me to post it.  I offer this in addition to Jeff's excellent procedure, and I submit any different opinions with respect.

The torque value for the four bolts that hold the AC units down is inch-pounds, not foot-pounds.  Threading the bolts in slightly, without the inside plate, makes moving the unit around to proper position from the inside of the coach much easier.

I chose to use RJ-11 jacks for connecting the "phone" cables, rather than cutting off the ends.  Cheap off Amazon.  I had a bad experience with tiny telecom wires long ago!

Unlike Jeff's FT, our FT has a wire present for providing 12 volts to the rear controller.  It exits the front cavity on the passenger side, and enters the rear cavity on the passenger side.

Regarding the wires for the Aqua Hot call for heat... 
Our coach is different from Jeff's and apparently others as well.  Instead of the call for heat wire having 12 volts, it leads (from the AC cavity) to a relay  that completes the ground.  I attached one of the brown wires to the 12 volt power in the cavity, same connection as the AC controller box.  I added a fuse holder and a 5 ampere fuse, the smallest I had on hand.  The second brown wire attaches to the call for heat wire.  What is different is that my coach has relays for the living room and the bedroom thermostat circuits.  (The bathroom does not.)  There are two relays, above the Aqua Hot unit, on the back side of a rafter where they are hard to see.  I did not have to make any changes in the AH box, though I had it open for testing.

The relays are shown on my wiring diagram A-6204.  (Maybe your wiring diagram is different?)  Two "Bosch" relays convert the +12 VDC on the wire to a ground of the wire A7A.  This produces the "ground the wire" that is described in Jeff's procedure, and in other people's comments.  It will be easy to determine what configuration you have.  If you ground the "call for heat" wire and the blower runs, you don't have the relays.  If this does not work, look for the relays in the AH box.

Rather than have a closet door that won't open completely, or cut the top of the door, I installed the old ceiling cover on the rear AC.  The openings roughly line up, and I will block off the non-duct cool air outlet anyway.  It may be slightly less efficient – I will let you know if it causes problems.  The closet door, of course, opens like it did before.

The heaters work like they should.  I have the ACs on and I will let them run for a few days to give them an exercise.  At the moment, it is too cold inside for the compressors to kick.  The new thermostat has a large screen, big buttons, and is backlit.  It is a joy!

I will be pleased to answer any questions you have, now or in the future.

I was under the impression the dometic ac units and the thermostat use 4 wire reverse phone cables.  Am I wrong?

I think that is correct Peter but they might be 6 wire cables and plugs. I wanted to use then so I made connectors with pigtail wires to connect to the Furrion control wires and thermostat.  I also added remote temperature sensors for each AC unit.

That is true. Though many of those older systems have couplers inline at just before the a/c jack. So one wonders if the coupler is reverse or straight through? Guess it might depend on the RV manufacturer and the cables on hand. However, the Dometic 4 button thermostat and circuit board are designed for data (reverse) cables with 6p4c RJ11 plugs.
Jim

2002 U320

Frerichs Electronics

Thanks for posting this. I installed my Chill's in the spring and everything was great, but when I grounded the Aquahot lead, my fans and pump would not run.  After reading your post, I spent 20 minutes in my units putting 12v to one brown furnace wire and one brown wire to the aquahot lead. now everything is working great.

I am pleased!

One or more of the messages of this topic have been moved to Foretravel Renovations (https://www.foreforums.com/index.php?board=4.0) - https://www.foreforums.com/index.php?topic=49298.0 (https://www.foreforums.com/index.php?topic=49298.0) since it's a somewhat different question.