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Topic: Update on Replacing DuoTherm A/C with Analog Controls (Read 1554 times) previous topic - next topic

Update on Replacing DuoTherm A/C with Analog Controls

I know this has come up before but for the newer members who own older Foretravels I thought this information might be helpful. DuoTherm/Dometic does not offer direct replacement units for the old analog thermostat air conditioners even though they may say they do. Their replacement units require adding a digital conversion kit costing around $300 or you must replace the interior plenum (the plastic air distribution device on the ceiling if you don't have a ducted system) for and additional $122.00. If your system is ducted I'm told you have to use the conversion kit.

"When you replace an A/C unit from DuoTherm/Dometic on an older coach, you have to convert to digital or use a ceiling mounted plenum with internal controls". I had read this in previous posts but I could not imaging that a manufacturer like Dometic would not make a plug and play replacement air conditioners for the older RV's. I called their customer service explaining what I was trying to do and gave them the serial number and model number of my old bedroom unit. They checked their computer and said the had a direct replacement for my old unit and gave me the model number of the replacement unit.  I questioned whether I would need to convert to digital and was told no, this would be a "Direct Replacement I could use my old roof shroud and interior plenum".

Knowing the credibility of our members, I still questioned what I was told and called several of the local DuoTherm authorized installers and asked them for quotes and if I had to convert to digital. Six of the eight I contacted said I had to convert to digital. Two said they had called their Dometic tech people and were told there was a plug and play direct replacement. I was quoted about $800 for an installed replacement unit. I chose the largest RV dealer in Oklahoma and the new unit came in yesterday. It did not work with my old analog thermostat and they did not have a digital conversion kit in stock for my unit.

Its really hot here and I did not want to go through holiday weekend without our rear air conditioner, so I bought a new plenum with ceiling controls, it eliminates the need for the wall thermostat that they did have one in stock. I now have bedroom A/C but I will still have to purchase and install the digital thermostat conversion if I want the blower to go off when the compressor goes off or to use my heat strip and freeze preventer. The final price will be around $1,200 which was the average quoted from most of the dealers

The bottom line is when you are told you will need to convert to digital if you replace your A/C with a DuoTherm, believe it. DuoTherm/Dometic is not smart enough to produce a direct plug and play replacement for the thousands of old RV's still on the road. Or, buy a Coleman if you can stand the extra height on the roof. At least they support their older A/C units and the dealers claim they are more reliable than the Dometics. 

I started
The selected media item is not currently available.Kent Speers
Locust Grove, OK
1993 U300 SSE 40' (Restored at FOT 2009) Build 4323
720 watts Solar
6V92TA DDEC Silver Engine
2014 Subaru Outback

Re: Update on Replacing DuoTherm A/C with Analog Controls

Reply #1 –
Kent,

Really bummed to hear about the problems. Like going to a restaurant, ordering off of the a la carte menu and having the total be over twice what you were expecting. And then you have to add tax/tip. :-(

For those facing a similar situation, the cable adapter kit is:

3106986.007 (the 007 must be a license to kill or at least steal) conversion to comfort control center.
The kit consists of:
Male adapter cable 3106958.006
Female Adapter Cable 3106958.014
Installation instructions 3106957.016

The digital control center in white is:
3109228.001 or black .019

Heat package is 3101121

Might find the whole enchilada on eBay, Craigslist or?. I just hate to get ripped-off.

I can photo and post if anyone would like to look at the docs.



Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: Update on Replacing DuoTherm A/C with Analog Controls

Reply #2 –
Betcha Colaws would have some used Comfort Control centers reasonably priced...
The selected media item is not currently available. Dave Head & Megan Westbrook
Titusville, FL - The Great Outdoors
'98 270 buying this month
Toad is a 2018 F150 XLT

Re: Update on Replacing DuoTherm A/C with Analog Controls

Reply #3 –
Are these adapter kit part numbers universal for all new Duotherm units?
The selected media item is not currently available.Kent Speers
Locust Grove, OK
1993 U300 SSE 40' (Restored at FOT 2009) Build 4323
720 watts Solar
6V92TA DDEC Silver Engine
2014 Subaru Outback

Re: Update on Replacing DuoTherm A/C with Analog Controls

Reply #4 –
Kent,

Don't want to steer you down a wrong road. Below the info above is this quote "The 3106986.007 Cable Adapter Kit will permit the new Climate Control Center (CCC) to be installed with the existing 10-strand thermostat cable".

I did find an apparently up to date website selling Duo-Therm and Coleman products. They do list the above part number so I am assuming it (is that dangerous?) to be correct. Here you go: http://www.centraltrailer.com/rvcatalog/Appliances.pdf

To bad it is Saturday or you could call Dometic but you could give these guys a ring. The word "central" in their address may mean they are open now.

Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: Update on Replacing DuoTherm A/C with Analog Controls

Reply #5 –
When I bought the new Coleman Mach power saver units last year I had to replace the interior ceiling units too.  I didn't understand why as the controls are essentially the same.  I'm going to add remote control breakers for the A/C units with the control switch mounted in the cab so that driving down the road I can kill power to the A/C units so as to shut down or start up the generator.  I will probably do this prior to my next big trip. 
Dwayne Keith
1992 U240
3116/MD3060

Re: Update on Replacing DuoTherm A/C with Analog Controls

Reply #6 –
FWIW - on my 91 U225 I just replaced the rear AC unit; still have to change out the front. The original Coleman was replaced with a new Mach III. The footprint on the roof is smaller (wow - I can see shiny gelcoat  :) ), and the ceiling cover is also smaller, which will necessitate some interior modifications. The controls were changed only in that they were moved from the roof unit to the ceiling cover.

Steve
1991 U225 Grand Villa

Re: Update on Replacing DuoTherm A/C with Analog Controls

Reply #7 –
Kent thanks for the info, I know that i'm going to have to replace my Dometics in the near future. How is the noise, i've heard that the new ones are louder or have MORE vibration than our older units?
Kerrybob
1995 U295
1997 F250 4dr

Re: Update on Replacing DuoTherm A/C with Analog Controls

Reply #8 –
Kerry, the new one is probably 40% louder. The noise is however wind noise not the compressor. The compressor vibration seems to be about the same. I presume that they are either using cheaper, louder fans or that these new units have to move more air to offset the lower cooling efficiency of the new Freon or both.

I think it would be better if I had ducted cooling. The new plenum (ceiling unit) seems to have more nooks, crannies and air outlets in its configuration that may produce noise. I am going to try to adapt the system to the old plenum when I get the digital conversion kit. We will see if its quieter then.
The selected media item is not currently available.Kent Speers
Locust Grove, OK
1993 U300 SSE 40' (Restored at FOT 2009) Build 4323
720 watts Solar
6V92TA DDEC Silver Engine
2014 Subaru Outback

Re: Update on Replacing DuoTherm A/C with Analog Controls

Reply #9 –
When our front Dometic Penguin unit quit last year, we ordered a "drop in, replacement" unit from MOT and arranged to have it installed when we were next in Nac. We came back in March of 2011 and they popped it in ... had to also get a new thermostat to match, and even though it was supposed to be an exact replacement, I was taken aback at how loud it seemed. The unit was installed (with lots of other work on the coach), we tried it out a little bit after we left MOT on Friday afternoon and Saturday and left Nac on a Sunday. By the time we got to Austin, I was not happy and began calling MOT on Monday to register my feelings on the noise and vibration ... which seemed really excessive when compared to the original unit in the rear.  We had lots of speculation about what could be the issue ... different refrigerant requiring different fan size, gaskets needing to "settle and compress", rubber bushings, bolt heads tapping, blah, blah, blah. We suffered with the noise through the Spring and early Summer, gathering information and waiting to get back to Nac.  Now, returning to Nac to hand the '95 coach to it's new owner and move into our "new" '02 ... we took up the A/C issue with MOT and started trouble shooting the noise.  They did a lot of work that I think should have been done at installation, bushings, padding on lines that knocked or vibrated, bolt heads, etc.  They also corrected the wiring so that the fan would operate on all 3 speeds, and not just HIGH.  I am glad the new owner has an AC unit that cools well and also is MUCH quieter ... but I wish we had had the opportunity to let MOT effect the changes while I was still living in the coach!  We also found out that the "exact replacement units" are manufactured for coaches with ducted air, needing a different fan that runs at higher rpms ... thus louder and more vibration.  That would have made a bit of sense to me, had I heard it. 
Carol & Jeff Savournin
Usta have a '93 U225 36', Usta have a '95 U320 40', Usta have a '02 U320 40'
Usta have a 2006 Born Free, Usta have a 2011 Phoenix Cruiser
Usta have a 2012 Jeep Wrangler Unlimited 4dr
"Your time is limited, so don't waste it living someone else's life."  Steve Jobs

Re: Update on Replacing DuoTherm A/C with Analog Controls

Reply #10 –
As noted in a previous post, we just replaced both our roof A/C's with 15,000BTU heat pumps(Dometic). Camping World did it. EVERYTHING but the wiring from thermostat to unit had to be replaced. New digital thermostat. Wiring conversion kit, and of course, the units themselves.$3,700, out the door. How do they cool? Very well. Are they louder than the old (un-ducted) units? Definitely.
Steve & Ginny Hill
96 U295 36'/Wrangler
Tampa
 

Re: Update on Replacing DuoTherm A/C with Analog Controls

Reply #11 –
Quote from: Steve & Ginny Hill –
As noted in a previous post, we just replaced both our roof A/C's with 15,000BTU heat pumps(Dometic). Camping World did it. EVERYTHING but the wiring from thermostat to unit had to be replaced. New digital thermostat. Wiring conversion kit, and of course, the units themselves.$3,700, out the door. How do they cool? Very well. Are they louder than the old (un-ducted) units? Definitely.

Do you have ducted air or the ceiling plenums? I considering an heat pump for the front A/C. Do you mind sharing your rationale that lead to the purchase of a heat pump? Since the new ones are so much louder, I am now thinking of staying with the old furnace and space heaters in the winter months rather than put up with the noise.
The selected media item is not currently available.Kent Speers
Locust Grove, OK
1993 U300 SSE 40' (Restored at FOT 2009) Build 4323
720 watts Solar
6V92TA DDEC Silver Engine
2014 Subaru Outback