Chinook RV Forum

It is currently September 22nd, 2017, 12:13 am

All times are UTC - 8 hours




Post new topic Reply to topic  [ 10 posts ] 
Author Message
PostPosted: May 16th, 2017, 6:16 am 
Offline

Joined: December 31st, 2016, 5:57 am
Posts: 113
It’s finally cool enough to test if my furnace still runs after removal of the rooftop air conditioner. I suspected trouble after ‘open circuiting’ wires that were integral to the Duo-Therm ‘Comfort Control Center’ with temperature sensor. This little box with LCD display is remotely mounted forward of the overhead bins on the driver’s side.

As I anticipated; nothing - no power to the unit! Relevant items are dip switches in the departed A/C for furnace selection plus connector control cables and a RJ-11 4-conductor telephone cable that obviously no longer “talk” to the Control Center.

So, quick question for the site gurus - is there a simple way to reroute the required voltage / data to the controller by splicing remaining wiring in the rooftop somehow and fool it to thinking the AC is still there? I would still like the option of furnace operation with basic on/off and temperature selection choices. Perhaps the furnace's squeaky squirrel-cage fan will convince me otherwise and the Chinook weight-loss program will continue!

_________________
Ted C. / SW Arizona
"The Blue Chook" 2002 Concourse Dinette on 2001 E-350 chassis w V10


Last edited by Rokrover on May 16th, 2017, 1:39 pm, edited 2 times in total.

Top
 Profile  
Reply with quote  
background-color: #C1CAD2
 

PostPosted: May 16th, 2017, 1:24 pm 
Offline

Joined: December 31st, 2016, 5:57 am
Posts: 113
Silly me - the solution is elementary after a bit of online research. After downloading the schematics for the Suburban NT 16S gas furnace it became apparent all I need without the A/C is a basic analog ‘heating-only’ wall thermostat. I got the Suburban model 161154 and shall proceed to dismantle and discard the old controller and figure out the ‘heat anticipator’ setting I need. Should be a basic two-wire connection then after I adapt to the RJ-11 connector in the board behind the Duo-Therm Comfort Controller. I should have heeded Einstein's quote below my signature line!

PS Our posts crossed, Blue~Go.

_________________
Ted C. / SW Arizona
"The Blue Chook" 2002 Concourse Dinette on 2001 E-350 chassis w V10


Last edited by Rokrover on May 16th, 2017, 1:42 pm, edited 1 time in total.

Top
 Profile  
Reply with quote  
PostPosted: May 16th, 2017, 1:36 pm 
Offline
User avatar

Joined: July 31st, 2014, 1:01 am
Posts: 1828
Location: 1999 Concourse
Yep, that's right. Once you remove the air-con the "Comfort Control" no longer works (and is no longer needed). Any old thermostat will control the furnace. Or you can go fancier with timers and etc., but the upshot is nothing beyond a "normal" thermostat is needed.

(Maybe one could somehow reinstate the Comfort Control, but in the normal order of things it stops working.)

_________________
1999 Concourse


Top
 Profile  
Reply with quote  
PostPosted: May 16th, 2017, 4:15 pm 
Offline

Joined: December 31st, 2016, 5:57 am
Posts: 113
Blue~Go wrote:
Maybe one could somehow reinstate the Comfort Control...

Actually, in my experience the original Comfort Controller had needless options for the Chinook’s interior space. Only ‘Zone 1’ was relevant and I never used the A/C in the available ‘fan only’ and ‘heat pump’ modes.

_________________
Ted C. / SW Arizona
"The Blue Chook" 2002 Concourse Dinette on 2001 E-350 chassis w V10


Top
 Profile  
Reply with quote  
PostPosted: May 16th, 2017, 6:48 pm 
Offline
User avatar

Joined: July 31st, 2014, 1:01 am
Posts: 1828
Location: 1999 Concourse
Oh I completely agree. I would never try to "reconstitute" it for use with the Air-con gone. I consider it a bonus that it no longer has to be used (for just the furnace) and one can choose a thermostat. I just felt like I shouldn't say it wasn't possible, since I really don't know.

_________________
1999 Concourse


Top
 Profile  
Reply with quote  
PostPosted: May 17th, 2017, 11:08 am 
Offline

Joined: December 31st, 2016, 5:57 am
Posts: 113
Time out to recover from a bruising ride down the inevitable ‘Cascade of Consequences' trying to wire my new analog heat-only thermostat to the furnace!

The day started out well with a smooth installation of a new steering damper. I followed forum advice and chose a Monroe Magnum SC2995, made in the U.S.A. no less. Next was the simple installation of a Camframo Ultimate 757 DC Cabin Fan to make do without an air conditioner and 110V. The fan now plugs neatly into the 12V outlet under the sink and moves a lot of air.

Feeling pleased with myself I then moved on to the thermostat. I mean, how hard can it be? Just two wires to form a loop with the blue leads to the furnace relay. First step was to expose the furnace and confirm the relay wiring to thermostat. No luck as it quickly runs out of sight then quite a distance behind carpeted panels.

The other exposed end at the thermostat is not helpful either as it is an ambiguous 4-wire RJ11 telephone jack with flimsy 24 gauge wires. Hardly sufficient gauge for 0.7 amp needed over 15’ to the furnace relay. These ran to a logic board in the old digital Comfort Center controller and from there up to another board in the discarded air conditioner.

I tried to trace the telephone wire back from the thermostat to hopefully discover the heavier blue wires from the furnace - to no avail. I merely confirmed after laborious disassembly of the overhead bin flooring the wires disappear along with other circuits and snake into the wall and ceiling space. Of course I looked at my Chinook owners manual for guidance but it had no wiring schematic for thermostat to furnace.

So my next idea is to run the new wiring across the forward overhead bin and find a neat path to tuck out of the way down to the furnace. Perhaps I should test the circuit first before getting too deeply committed. Surely inspiration will come after the therapy of exposing my travails in public and a senior's nap.

_________________
Ted C. / SW Arizona
"The Blue Chook" 2002 Concourse Dinette on 2001 E-350 chassis w V10


Top
 Profile  
Reply with quote  
PostPosted: May 17th, 2017, 1:19 pm 
Offline
User avatar

Joined: July 31st, 2014, 1:01 am
Posts: 1828
Location: 1999 Concourse
I can tell you where the furnace wiring is on my '99.

Starting at the "brown box," the furnace has its own DC power wire/fuse. I have in my notes on the original wiring "#6) 20 amp -- 12 gauge red - furnace." I don't believe this wire serves anything else.

This is corroborated in the 2000 manual, here is an excerpt. Note the #6 fuse position. BTW, the model "with Nu Heat" has the same wiring on position #6.

Attachment:
2000 manual fuse box diagram.png
2000 manual fuse box diagram.png [ 104.92 KiB | Viewed 219 times ]


I'm going to look in my photos from when I took out the furnace to see what color the wire is when it gets around to the furnace. BTW, there is a yellow wire in that same area that goes into the floor. I am 99.9% certain that feeds the propane gauge (signal goes to monitor panel).

Here are a couple of photos of the wiring at the furnace end. First one is before I disconnected anything. Second one is after but gives more of a big picture. The power wire is still the red 12-gauge wire.

Attachment:
IMG_5316.jpg
IMG_5316.jpg [ 132.76 KiB | Viewed 219 times ]


And yes, that red wire goes through the channel that's up in the roof/wall junction area behind the long cabinet.

The path of the "phone cord" is through the roof on a diagonal over to the area in the overcab behind the solar controller, then across the overcab ceiling (right behind the face panel in the open), then through the wall chase and into the cabinet with the Comfort Control.

Does this combination of information help you with the thermostat wiring?


Attachments:
IMG_5318.jpg
IMG_5318.jpg [ 217.94 KiB | Viewed 219 times ]

_________________
1999 Concourse
Top
 Profile  
Reply with quote  
PostPosted: May 17th, 2017, 2:15 pm 
Offline

Joined: December 31st, 2016, 5:57 am
Posts: 113
Thanks Blue~Go - most helpful. It is sound policy to take pictures BEFORE pulling stuff apart. Yes, #6 is the 20A furnace fuse I removed before starting work.

I have progressed by mounting the new thermostat and running a 16 gauge wire pair, neatly tucked and routed up and over inside the forward bin then down to the furnace, completely bypassing that circuitous and now useless “phone wire.” Some drilling was required in the name of expedience - a 5/16” hole in the bin wall behind the driver. The wire pair is out of sight there in that little nook.

This is from the Suburban NT-16SE Installation Manual:
“Connect the thermostat wires to the blue wires on the right side of the furnace. If your furnace is equipped with a thermostat that has an adjustable anticipator, the anticipator should be set at .7 amps.”
Tomorrow I plan to finish the connection to the blue pair shown in your middle attachment and disconnect that spliced red / white phone wire. Then we shall apply ze voltage and see if she comes alive!

Oh, I can vouch for my new Camframo cabin fan that cooled me down nicely working with my head stuck inside storage bins that were becoming ovens as the day progressed. Their light strips also contributed heat so I should consider the LED conversion others mentioned here.

_________________
Ted C. / SW Arizona
"The Blue Chook" 2002 Concourse Dinette on 2001 E-350 chassis w V10


Top
 Profile  
Reply with quote  
PostPosted: May 18th, 2017, 8:14 am 
Offline

Joined: December 31st, 2016, 5:57 am
Posts: 113
It’s ALIVE! The furnace fired right up after completion of the wiring job. It took 20’ of wire to cross over from thermostat to furnace. I used 16 gauge blue and white primary wires. The first attachment the new analog thermostat terminating my new blue / white pair mounted on the bin with the back of the removed digital Comfort Control for reference. The other phone wire pair must be to power this unit. Ignore the wire colors in the picture as this was just a test piece used for illustration purposes. The original is now tucked out of the way under the bin floor.

The second attachment shows the splices I made to the blue furnace wires. The red and white phone wires were cut off and can be seen just above my thumb in the furnace bay. I've learned my lesson not to assume these jobs are simple plug and play. The Chinook wiring is so well routed only major gutting of the interior could expose it all. I wasn’t about to go that route.

Brief Recap:
* Remove air conditioner = open circuit to controller, hence furnace becomes inoperative
* For heat only a simple two-wire analog thermostat is sufficient
* For proper burner on/off duty cycle the anticipator setting is 0.7 amps
* The wires must not be too thin (e.g. 24 gauge phone wire) as voltage drop then becomes an issue

Now for road trip without fearing the cold. I should end with another pithy quote: “Problems that remain persistently insoluble should always be suspected as questions asked in the wrong way”


Attachments:
IMG_0127.jpg
IMG_0127.jpg [ 106.77 KiB | Viewed 206 times ]
IMG_0119.jpg
IMG_0119.jpg [ 66.14 KiB | Viewed 206 times ]

_________________
Ted C. / SW Arizona
"The Blue Chook" 2002 Concourse Dinette on 2001 E-350 chassis w V10
Top
 Profile  
Reply with quote  
PostPosted: May 18th, 2017, 12:50 pm 
Offline
User avatar

Joined: July 31st, 2014, 1:01 am
Posts: 1828
Location: 1999 Concourse
Excellent! Thanks for following up - it's always nice to hear the rest of the story (with useful details for other Chinookers).

I do like a simple thermostat where you can just reach over and push the lever. In my (previous) camper van I could reach if from the pillow :D No getting out from under the blankets until it was warm. Who says you can't have luxury in a small RV.

_________________
1999 Concourse


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 10 posts ] 

All times are UTC - 8 hours


Who is online

Users browsing this forum: No registered users and 2 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
cron
Powered by phpBB® Forum Software © phpBB Group