Coleman-Mach to Honeywell RTH3100C

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charwan

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Joined
Jul 22, 2009
Posts
7
I'm trying to install or replace the Coleman-Mach with a honeywell RTH3100C thermostat and the wire colors DON'T match up.  Has anyone done this and if so can you tell me which color goes where.  The RTH3100C has terminals  as follows.  E Aux Y G O L R B C  and the Mach wires are.  1- Gry (freeze & Exclusion Relay  2-Red (+12vdc) 3-Blu -(12vdc) 5-Yel (cooling Comp. #1) 6-Org (cooling Comp. #2) 7-Blk (Fan Hi) 8-Wht (heat pump) 9-Pur (Fan low)  Any help on this would be appreciated  Many Thanks  CharWan 
 

Duner

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Jan 7, 2009
Posts
162
Location
Camarillo, CA
First, welcome to the forum.

Second, substituting a "generic" thermostat for the Coleman Mach will not give you the same functionality, for example operation of the gas furnace, two speed fan operation, and three strike lockout.

When my Coleman broke 5 yrs ago, I replaced it with a RiteTemp 8085C digial set-back thermostat from Home Depot.  I spent hours analyzing the wiring diagrams and running it thru all the functional temp/set combinations.  The pdf attachment below shows the wiring conversion that works for the RiteTemp.  I'm not sure, but I suspect that the Honneywell and the Ritetemp both have the standard thermostat wiring.  With this wiring, the "Emergency Heat" will control the gas furnace.  The fan speed will be high only (no low speed choice).  Both compressors will cool/heat, where the Coleman will use just one compressor as the temp approaches the set temp.  My Winnie has the Energy Mgmt System and it still functions to cut out the 2nd compressor if the power exceeds 30 amp.   

Good luck,
Bill
 

Attachments

  • Coleman to RiteTemp Wire Conversion.pdf
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charwan

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Joined
Jul 22, 2009
Posts
7
Dunner it seems you have put a lot of though into this.  I have found out what all the terminals are for the RTH3100C which seems to help.  HOWEVER, it is for 20+ volts AC but has the same terminals EXCEPT as you say only one fan speed.  I have a message into Honeywell and hope they can say if the voltage makes a difference.  Thanks for the quick replies because I have CUT the wires.  Charles  Man I love this spell checker.
 

charwan

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Joined
Jul 22, 2009
Posts
7
Here is a list of the terminals for the RTH3100C are as follows.    R-24VAC  O-Changeover valve to cooling  B-Changeover to heat  Y-Compressor Contactor  G- Fan Relay  C-24VAC  common  Aux  Auxiliary heat relay  E- Emergency Heat Relay  L System Monitor  Maybe this will help someone  Charles
 

carson

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Joined
Sep 1, 2006
Posts
4,919
Location
Florida, USA
Excuse me, but I seem to missing something...

  I don't think there is any way it will work. You have no 24 VAC on board. A home thermostat just can't be used in an RV.

  I replaced my Coleman with a Hunter thermostat, quite easily done. It runs on a couple of AA batteries. My batteries are 3 year old and still working fine.

  Let me know where I am wrong.

carson FL
 

Duner

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Jan 7, 2009
Posts
162
Location
Camarillo, CA
Yes, mine runs on batteries too.  It uses relay contacts to switch +12v and ground to control the various functions. 

The terminals for 24 vac on the Honeywell could be used only for replacing an old home t-stat. 

Bill
 

charwan

Member
Joined
Jul 22, 2009
Posts
7
Duner said:
Yes, mine runs on batteries too.  It uses relay contacts to switch +12v and ground to control the various functions.  

The terminals for 24 vac on the Honeywell could be used only for replacing an old home t-stat.  

Bill

Bill your's also runs on 24VAC ONLY. that's if you Do not run it on batteries.  I have to take it that you also have 12vdc to run the blower relay and heat.  Is your system a heat pump?  If your running 12 vdc and thermostat says 24 vac why won't mine work? Hey, I just went and looked at your site .  I have an 04 Adventure 34.  Should be the same thermostat as you took out.  Charles
 

charwan

Member
Joined
Jul 22, 2009
Posts
7
I'm still working on this.  The RTH3100C will not work because it does not have a duel system like we have.  I'm picking up a Carrier Thermostat and it has the duel controls and will post how its wired so if someone else has this trouble its here.  CharWan
 
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