Coleman Mach 8232 series to Atwood

[jdubya]

I have two ancient (2003) Coleman A/C units which are ready for replacement. The system is run by the Intellitec 00-00591-200 controller and a no-longer-available Climate Controller also by Intellitec.

I want to replace these with two 15K BTU Atwood 15028 with 15022 interior cover. I have seen others talking about doing this, but I am wondering what I will run into.

The front A/C has a multiwire cable that plugs to the controller encased in a nylon mesh of some sort plus a Romex 110 ac cable, a 2-wire thermostat cable and a six-wire cable that plugs to a plug that has a short run to the controller of the A/C. this unit runs the furnace (ie, switch the thermostat to heat and the relay picks on the front A/C to provide power to the furnace which then uses the thermostat to call for heat or not.
Update: I am not able to find where the wires from the Climate Control go. They look like zip cord for speakers, but none of the units use that type of wire. They plug in like a phone plug on the thermostat, but I can't find the other end anywhere.

The rear A/C does not have the multiwire cable, but it does have the Romex for 110 ac, a 2-wire thermostat cable and a 6-wire cable to the controller, but the cable feeding into that cable does not have anything in the middle pair (furnace?)

I do not see that multiwire cable, but it makes no sense without it so I will look again for that.
Update: the cable in the mesh is there on the rear unit - I just couldn't see it. It looks like a 9-wire plug with about 6 wires in it. Hard to see.

From the Atwood, I don't see any of the need for Intellitec except that I would like to take advantage of the current sensing and shedding features of it. I would also use it for furnace operation. I am assuming that the new Atwood thermostats won't control the furnace on and off for temperature - just on and off for power available. If they will operate as a thermostat for the furnace, that would be good.

To take advantage of the current features, the output of the Intellitec would have to be the Atwood's ac supply which I think is already in the Romex cables. After that, everything should run from the Atwood units and thermostats.

The only problem I have noted so far is that the cable for the thermostat on the Atwood is a 4-wire communications cable. I am hoping to be able to pull a phone wire or a LAN cable from each of the units using the existing 2-wire cables from the Coleman to get the new setup in place. That could be a bearcat - depends on how the wires were installed - hopefully down the duct.

The MH is a 2004 Fleetwood Flair 33R with 6500 Onan genset. I could make the switch to direct wire, but I like having the automatic sensing of current plus the transfer switch is part of the Intellitec system although a separate box.

Anyone care to give me a 'this will get you' or 'you need this' to help me out with this? I have a method of hoisting the units onto and off from the rig all figured out. (Remote controlled winch mounted to the roof purlins and the coach parked directly below where I want it to go.)

Has anyone done this - what problems, what extras, any idea about trouble between Intellitec and Atwood? Etc.

Thanks in advance!

[jdubya]

I have also tested the A/C that is broken and found that it is drawing too much current so that the Intellitec shuts it down. The windings read 5 ohms and infinity to the case. The cutoff is showing continuity, I replaced the start and the run capacitors. I disconnected the black wire from common and jumped the unit with an extension cord connecting from the white to the black and blew the 15 A circuit breaker, well, I mean it opened as it should.

Of course this is with a 40 foot extension cord, so the voltage probably was not good enough to kick it over - I might try using it on the 20 A cb and see if that makes a difference.

I am fairly certain that the compressor is stuck which means replacement.

The single A/C would run the coach in Oct, but the bedroom is what we want cooled and both sets of fans running don't cool the bedroom sufficiently.
I could just move the working unit to the rear and replace the front with one of the new ones so that if I can't get the repair done in time we will have air to the bedroom.

[jdubya]

Well push is becoming shove. I need to order the A/C to get them here in time for me to replace them.

In order to achieve the desired upgrade to the Intellitec thermostat, which I now realize is what I am really wanting to do, and maintain the Intellitec functions for shedding, the options come down to doing everything the same for the new thermostat - which is to modify it so that the on/fan-on case is interruptible and the compressor-on case is interruptible for shedding purposes. These are all the same - I can do it with small relays in line so that if the Intellitec says that the shedding should occur, the relay will drop out disconnecting the thermostat. This means as many as 5 relays per unit (I think fewer because the fan uses a common, but whatever that would be worthwhile.

To replace my units with larger ones, requires that a Coleman of approximately $1000 is needed. That is $2000 plus cost of thermostats ($100) and shipping ($200) puts it in the very difficult situation. The Atwoods would cost $700 including thermostats or $1400 plus shipping ($200).

To replace with a Mach 3 Coleman is about $1200 plus shipping and no upgrade at all.

You can see why the Atwoods look pretty good to me. But if I replace them, I might spend most of my time at the lake in Oct trying to get them to work.

[jdubya]

wa8yxm: Thanks for the reply. Yes, I had heard that report before as well. My question would be why not use air pressure to blow it back and/or a vacuum to help you? And also, why not just put a finer mesh screen on the inside of the intakes for the 'blower' style?

Your point is well taken, however. It is much more difficult to deal with the cleaning on the blower style.

BTW on a different issue - I am wondering why on the Coleman, the fins on the condenser look like they have been bashed in by rocks or hail - why would that happen on a sucker? (Maybe has nothing to do with it.) I wonder because they were like that when I got it and haven't changed - curious.

[wa8yxm]

I have not done that but I've gone the other way (From something else (Carrier) to Coleman)

I will recommend you stick with Coleman.. HERE IS WHY:

My Rv Technician told me "Colemans Suck, Dometics (in fact nearly all other Air conditioners) BLOW" By that she meant that a Coleman the fan sucks aire in via the condenser from outside and blows it out the sides Where as allt he others suck in from the side vents and blow out through the Condenser.

NOW.. Going down the road.. "Blowing" might be a bit more efficient, but parked it won't make a whole lot of difference (Sucking slightly better in fact, very very slightly)

BUT here is where the real difference is.. My first time where I am not this summer it was Cotton Wood Season so naturally when I got to the other park CLICK went the circuit breaker (As the system gets HOTTER pressures increase the pump works harder and the breaker goes CLICK) Well Time to go up and de-cotton them

On the old one: Remove outer cover, Remove inner cover, Since my hands are XXL Remove fan, Clean, Reassemble

On the Carriers the inner cover is a few screws to remove but on my Advent air
I replaced the other Carrier with an Advent air) It is bent metal tabs and tape, You can only unbend/rebend those tabs so many times. But Advent Air is made in China so the fan (Shaped a bit like a tire after all) Turned out to be a China Bomb , when it blew up I replaewd it with a Coleman fan so not it sucks too.

To clean: Remove outer cover (4 bolts on Coleman 10 screws on Advent Air)

Remove cotton from OUTSIDE of condenser

Replace cover Job done.

[jdubya]

Now rereading some of this info, I noticed Doug's comment about Intellitec, stating that he had never received any negative comments about Intellitec. I agree with that in that the design is fine. The installation in my coach was a little weaker than I would have liked. But the main thing is that it is almost impossible to adjust the thermostats - if you change it, you cannot find the same spot the next time. The ergonomics are nuts - it is impossible to read the markings without a flashlight. The switches cannot be changed easily because of the detents between and then they are difficult to align with the appropriate mark. That wouldn't be so bad except that you have to change them each time the unit is turned off. If you could set it and then turn it off and back on without having to realign the switch on the right place, it would be usable. Another problem is that the AC1 is on the left side and refers to the front A/C, not the rear A/C. This is reverse from what it should be. The air temperature is sensed by two thermistors, one located immediately above the thermostat and the other 5 feet away inside the main cabin. They are too close together. It is like putting the thermostats in your house all at the downstairs cold air return plenum.

However, with all that - it still works quite well.

In addition, the thermostat is no longer available and must be replaced if a new thermostat is required.

So after looking at all of this again, it does not appear that the new thermostat will work well with Intellitec. The change over will require multiple devices to switch them if modifications to allow inputs to the power, compressor and fan functions is not easily accomplished.

what I mean is:
1) The Intellitec has to know when the power is turned on at the Atwood thermostat. By taking power from the same point as the Intellitec thermostat, input to the Atwood thermostat should be ok, but the Intellitec won't know about it. When the Intellitec thermostat is switched to a fan or fan/compressor combination, the Intellitec controller can determine what to do, but somehow the Atwood thermostat needs to do the same thing when it is switched on.
2) The Intellitec can assume power-on at the Atwood thermostat when none of the fan positions are powered on. That would initiate the Intellitec controller's timeout to the compressor. But the fan input needed is that any of the fan positions are on, not which one, and then the fan output from the Intellitec needs to be able to remove fan power somehow.

Shedding the power to the fan by Intellitec could be done by shedding power to the Atwood thermostat. In other words, the power to the Atwood thermostat would be the Intellitec power to run the fans. Intellitec's controller would be sensing that all of the power is being used and would not allow power to the two air conditioners or to either one as indicated by the 'shed' lights.

Then if power became available, the Intellitec would re-power the lines, but someone would have to turn the Atwood thermostat on in order to get things to work - so power to the thermostat as the fan function inhibitor does not work as previously was stated. The Intellitec controller needs something to tell it that the Atwood thermostat has been turned on. Right now, that would require a mod to the thermostat to provide such a pin out.

3) Once the Intellitec controller receives the input concerning power at the Atwood thermostat, it times out 2 or 3 minutes minimum to keep from turning on the compressor too soon and it immediately allows power to the fans. Again the Intellitec has to be able to control the input to the fan, but not necessarily the speed level - Atwood thermostat can do the speed levels. But to do so and allow the Intellitec to shed the fans, the Atwood thermostat would have to receive power for the fans from the Intellitec controller. It would seem logical that the fans selection would be powered from the on/off selection of the Atwood thermostat, so power to the fans could be interrupted by having a jumper (two pins - one out; one in) to allow normal function and also allow Intellitec's controller to intercept the fan function if needed. If it is not already available, that should be a fairly easy mod to the Atwood thermostat.

4) The Atwood thermostat would then select the fan speed and not be required to have the opto isolators to allow fan shedding. But now the power to the compressor has to have similar functionality. The fans have to be allowed to run and the Intellitec controller allowed to shed the compressor. The only way to provide this is to use the Atwood thermostat's fan power on (return pin of the pair for fan control) as the input to the Intellitec controller to operate the compressor shedding on the Intellitec. To allow shedding of the compressor, the Atwood thermostat has to receive power input for the compressor that may be interrupted by the Intellitec controller. The Intellitec controller's compressor line must be the input to the Atwood thermostat to power the compressor output of the Atwood thermostat. This means that the Atwood thermostat would require a modification to add a jumper pair again for fan out to compressor in on the Atwood thermostat.

5) The thermostat inputs on the Intellitec controller would have to be jumpered to the appropriate on level so that the controller is told that A/C function is needed all of the time, while the Atwood thermostat would actually turn the compressor on and off with the power thus provided so that shedding would be possible.

These two mods (actually four mods) would be fairly easy to accomplish if the locations for these functions is available and real estate on the board is available to allow the mods to be made. The mods would entail locating the points, severing the connection, installing a pin on either side and fashioning a jumper so that the unit will run as originally designed. These jumpers may already be available as test points on the board, but doubtful.

The alternative method as previously described is more complex, but this method probably voids the warranty.

[jdubya]

On further looking, I think I missed the 12 vdc supply for each that is needed by the Atwood and not used by the Coleman (as mentioned by others). There is a light adjacent to each of the A/C mounting holes from which I can tap the 12 vdc. I am not sure what uses this power, but I can get it easily if needed.

My current thinking is to mount the bedroom A/C thermostat in the bedroom on the bathroom/bedroom wall. This area is easily accessible from the area where the Intellitec controller is located. If the other thermostat cannot be placed on the wall near the entry door, I will consider placing it near where the temperature sensor for the Intellitec unit in the main coach is located. That area also has an access hole where I ran wires for extra outlets all the way from the rear of the camper and should provide access to that wall to string the Atwood cable.

The issue that I see is that the Intellitec unit expects to control the compressor and the fan. I think that it will require that the output of the Intellitec be accessible to provide the input for the Atwood which could mean that power from the Atwood to its compressor would have to intercepted by the Intellitec's output if the compressor was not allowed to run due to shedding. This could be done using a opto isolator or another relay local to the thermostat. The Atwood thermostat would operate the A/C compressor as long as the Intellitec compressor line for that A/C provided power to the relay to allow it to do so.

The On/Off switch for the thermostat would receive power from the Intellitec's power on wire that used to operate the thermostat on the Intellitec.

The Fan speed and all the features of the Atwood would operate from the Atwood thermostat and be turned off by the Intellitec for shedding purposes. The fan supply would be provided by the high speed fan output of the Intellitec and used to intercept the fan operation of the Atwood - it might take three more devices to provide shedding for the fans because of the three speeds. It will depend on whether or not the Atwood thermostat can be modified easily to allow one input for all three fan operations (which I doubt). So the outputs will have to be intercepted by relays or opto isolators similar to the compressor. This again is to provide the shedding function by killing the power to the fans. If the Intellitec power is not available, the Atwood output to the A/C would be intercepted. That would mean a total of eight mini relays or opto isolators.

The power to the Atwood A/Cs will not shed properly if the Atwood thermostat is turned off altogether.

The furnace would continue to be operated by the Intellitec thermostat. In fact, I don't think that the feed from the Atwood for the furnace makes much sense. It appears that the Atwood switches to furnace when it is unable to operate efficiently. But then it requires that you turn off the A/C fan and switch on the furnace using the switch on the Atwood thermostat. Whichever way, I will have the wires necessary to allow the power to the furnace to go through the Atwood A/C's relay and then have the furnace switched on so that when the relay picks the furnace will run using the setting on the Intellitec thermostat which will remain in place along with its thermistors.

So most of the work needs to be done behind the power panel in the bedroom. I am considering the removal of the 13" CRT TV and replacing it with a TV with blu ray player. If I did that, I could possibly move the Intellitec controller from behind the power panel into an area where it is more accessible (it actually has a test feature that is basically unusable where it is located) and put the new electronics into a black box where I will be able to get at all of the system. The transfer box would remain where it is.

[jdubya]

Thanks, Chris.

I read a similar detailed swapout from a guy with a Mach 3. I could not see in his wiring the same kind of stuff that is with the Intellitec. My coach is a Fleetwood Flair 33R 2004 gasser. I should add that the A/Cs are ducted.

The Intellitec in my coach has a dual thermostat in one unit (on the wall outside the bathroom) and a controller behind the power box in the bedroom. The cables are separate 110 ac to each (I assume from the transfer switch controlled by the controller. It also has a bunch of wires running into a cable that has to be going to the A/C. In the Coleman Mach (8632B6764 which Coleman denies is a good number) each unit has what looks like a 9-pin connector (I found that the 9-pin connector goes to the outside to the caps, fan and compressor (DUH!)) and several two-pin connectors. One of the two pin connectors goes to a thermistor attached to the evaporator coil, the others that have wires go to a stub cable that attaches to the cable from the coach. It has 6-pins in the stub cable and only four are used on it (rear unit) but the front unit has all six wires and appears to be feeding back to the thermostat with all six wires. I think both of these cables go to the controller in the bedroom.

Any comment on that?

I am going to pull things apart a little more to see if I can identify where these wires go - especially the 9-pin connector (it is laced into a protective netting so the wires are hard to see.) I am fairly certain that I have 6 wires to the controller for the Intellitec.

What I want to do is save the shedding feature which means that I will have to get the thermostat of the Atwood to run things when the Intellitec says it is ok by providing it with power.

If worse comes to worse, I could just install without the Intellitec, but..

Anyway, right now I am trying to figure out where these 9 pin (or whatever they are) go to. If they go to the intellitec, I will install the one thermostat (rear) in the bedroom where the cables go and the other next to the front door - along with the furnace feature - the wires (6) all appear to be there. Otherwise I might have to surface mount the thermostat wire on the front unit. Running the rear thermostat in the bedroom will be easy unless I decide to put it where the furnace control is instead.

The rear unit is in the main cabin to the rear of the kitchen (which is behind the entry door). The front unit is just forward of the entry door. The 6-wire cable appears to run toward the rear side of the door. The 4 wire cable that attaches to the 6 wire stub appears to run back towards the bathroom dressing area where the function controls and thermostat sliders are located. It is reasonably accessible from above (I hope).

Any thoughts?

[Chris_Bryant]

FWIW, discounting the Intellitec, I did a Coleman to Atwood swap this year on a Winnebago. Could not get enough wires to do it, so I had to run a new cable to the thermostat.
Coleman has power at the thermostat and runs the furnace from the thermostat. Atwood needs power at the roof unit, and runs the furnace from the roof unit.

[jdubya]

I did a bit more research today regarding Dometic vs Coleman. The company that became Dometic is a part of a larger company with home base in Sweden which started from the original gas-operated refrigerator. They purchased Atwood Mobile as a subsidiary in late 2014.

Coleman, on the other hand, is a US company - also part of a larger US company similarly structured like Dometic.

Atwood Mobile had a major business going in Australia where the Air Commander company was manufacturing the Cormorant Air Commander for larger rigs. They were making a move to use the Air Commander design to produce a superior air conditioner for the US market. They ended up purchasing Air Commander in 2013. Atwood Mobile was growing.

However, the company had feelers out for a merger, which was answered by Dometic. Dometic, IMHO, was attempting to respond to the 'threat' of the advanced A/C design being offered by Atwood in the form of their new heat pump dual-fan units as was Coleman. Dometic apparently saw an opportunity to get the advanced design of the Atwood Air Commander and to get a really big portion of the rest of the mobile products that Atwood offered, so the two merged.

There is no evidence in what I found to suggest that the Atwood Air Commander will be 'phased out', rather it appears that the Air Commander is a successful design with like 80% of the market in Australia, and the little brother is making big problems for Coleman and will be a major product for Dometic who has seen their A/C business falter in the last few years, due in part (IMHO) to problems with their heat pump designs and their low profile unit which have not been reliable. They have also mimicked the Atwood design in their smaller units. I would be very surprised if the Atwood name is taken off this Atwood design, although it appears that Dometic is already adding their name to the Cormorant Air Commander as it is now called the Dometic Cormorant Air Commander.

So my guess is that I hit the nail solidly when I suggested that companies purchase others for the reasons I mentioned and it appears to me like Dometic had both reasons in their merger with Atwood Mobile.

[jdubya]

I think that the Atwood is more popular on the longer tongue trailers. It has larger capacity, more air volume, and is less than $600 unducted.

Regarding Carrier, it is my understanding that they went completely out of business, including RV A/Cs - everything. (Correction: Carrier still is BIG in HVAC) But with the Atwood, aren't they (Dometic) supporting the A/Cs that they sell? E-trailer is a big pusher of the 15028-22 which is what I am looking at. Why would Dometic do that, just to make people angry with them? Maybe I should hold out for a fire sale on these?

BTW the RV A/C is essentially a throw-away unit. If it needs anything done to it, the cost of repairs is as high as a brand new unit. Why do you think I am even looking at a new one? Do you service these Coleman units when they quit and it is not capacitors? It takes too much time - it is easier to take off the old and install a new one.

Not sure what your 'learn' was about, I don't think I insinuated that Atwood was bought by Dometic to learn anything - just that their Penguin was having problems and companies buy other companies for other reasons one of which is to get something that the other company has. That could be technology all the way to sales areas. But I really doubt that Dometic would buy a failing company with the idea of slowly letting its product die under their name, but there have been stranger things done. The reason for buying out a company is usually either for money (company is failing but has business stuff that is valuable) or strategic advantage - maybe Atwood buying the Cormorant to sell in the US with specific changes was just a package deal when Dometic merged with the company who owned Cormorant (guessing). Perhaps Atwood was in so much financial trouble that it paid Dometic to take the losses against their earnings over a longer period.

The odd thing is that you seem to be saying that it is Coleman or forget it because Dometic is not going to stand behind the brand that they want to kill - even if their own version of it is rapidly dying.

Another guy mentioned that the Atwood pushed the air out from the inside through the condenser which he claimed made them harder to clean - in his estimation that was a 'down-date'. Here again, the Coleman pulls the air forward through the condenser which would seem to be inefficient if running down the highway. I have heard of people doing that, but never needed to do so myself. I did try it once and it worked. Auto air was enough for us while moving along so it wouldn't be an issue for us.

Well, anyway, thanks again

[dougrainer]

All I can say is Carrier tried to penetrate the RV market and they ARE a BIG Daddy in AC systems. They failed miserably. I have worked on just 1 Atwood. Why? Because NOBODY uses them at the OEM level on the dozens of RV's I work on. Same with Carrier. I worked on a few that some of the OEM's we sold used them and I was NOT happy with how they functioned and poor level of support from Carrier RV division. It did not take long for most OEM's to drop Carrier. Sorry you felt I "threatened" you. Not my intention. Just trying to get info and the problems that may happen so you could not say, I wish I had known about this. Maybe Chris can chime in. I know of nobody that has really worked on the Atwood AC's. Just see that IF they were a great thing OEM's would jump on them and use them. That is another problem. Since there are very few Technicians that have worked on them getting Service Centers to do any warranty work will be difficult. What happens if they do drop the Atwood like Dometic has told me? Look at the posts from people trying to get parts for their Carrier AC units. I deal with Dometic weekly and I was told that they purchased Atwood to slowly drop them from the market. They have thousands out there that need to be sold. After 50 years I doubt both RVP and Dometic need to purchase another Brand AC company to "learn" something. Doug

PS, in all the years, I have NEVER heard anybody complain about the Intellitec AC control systems(design and function) on Fleetwood

[jdubya]

Well, doug, thanks for that - it is what I was asking for - input. You don't have me on years of experience however. I have found that most often the problems with a maligned piece of equipment is not necessarily earned. I don't do my purchases based on other people's biases either, rather on the facts presented. And I appreciate your candor, but not your tone.

Now, what is it that I want to do that is a 'NEVER'? Change from Coleman to another brand made by Dometic that has features that I like while Coleman doesn't? Is it cheaper because it doesn't sell? Are people using them unhappy with them? What is going wrong that they cannot have fixed by now (it has been out for quite awhile). You are not the first who have said they are not a good unit, but the other guy's reason was that they are a knockoff of the Cormorant made in Australia - in fact, based on the installation manual, they are a cheapened version of Cormorant made by Dometic in Australia. And the cheapening was to replace several metal parts with plastic (shields, etc.) If you know something about that, I am willing to listen, but so far your rhetoric has been too broad and not aimed at persuading, rather abusive threatening which is of little help.

By the way, many companies buy out others to get something that the other company has that they want. That could range all of the way from a technology to sales areas. Why is Atwood cheaper? I can think of several reasons - one is that they make a better product for less money. Your suggesting that it is because they are inferior somehow - that is what I want to know - how are they inferior because what I see does not appear to be inferior - especially not to Dometic who is failing miserably with, what was it, the Penguin - not sure. So now they have a replacement called Atwood branded that has a pretty good name. Some problems with people who work in their customer service, but is that abnormal?

I don't know why Dometic and Coleman seem to have a lock on the US market. Some of the larger RVs use Dometic, but I cannot see why. My Colemans have worked reasonably well, too, but they are not without problems either.

I do know that for the time my RV has left that I own it, I do not want to spend a bunch of money on it. If I can get two working 15K with heatpump units that work, are lighter than the Coleman, quieter, lower power usage, have digital thermostats and can be made to work with my Intellitec unit (the part of it that I use), I am inclined to do so.

I am open to logical reasons, not to irrational threatening - you have been warned, really?

[dougrainer]

jdubya wrote:
@dougranier: about $400 each difference. Plus I can see no advantage to Coleman. Do you have some inside information or something? This Atwood is a trimmed down version of the Cormorant from Australia - supposed to be a pretty good unit. They are made by Dometic for Atwood, right?

The only option that I see is Coleman, but $1200 each plus shipping is steep while the Atwood is $700 plus shipping - that is almost $1000 difference. That is why I am seeking the information - why do I want to stay with Coleman?

Dometic PURCHASED Atwood to remove them from competition. Ask yourself WHY, is the Atwood cheaper. ALSO, Research and determine if the Atwoods are so much cheaper, then WHY do almost all the OEMs only use Dometic Or Coleman. I am giving you 38 years of experience as a RV Technician and still working. I would NEVER recommend that a customer do what you want to do. But, you have been given my take on this, so if you have a problem down the line you cannot say you were not warned:B Doug

[jdubya]

Another thing is that the Coleman doesn't come with the thermostat. The Intellitec is an enormous monstrosity that is virtually unusable as a climate controller. The settings require a flashlight to see, the setting of temperature is not reproducible, and now that I look into it more, I find that the Flair has the thermistors almost right next to each other. That would be ok for the furnace, but for the A/C not so good. If I can figure out how to do it, I will put the thermostats in different places. The bedroom one - in the bedroom and the other one near the access door. I suspect that these locations will be too hard to achieve, but I am still in the dreaming stage.