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Posted on May 17, 2008
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Duo-Therm by Dometic Thermostat

We are trying to wire this back up. Can you help?

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  • burton_mc Jul 27, 2008

    I have a new duo-therm dometic thermostat to replace my existing duo-therm thermostat. Both units have 6 wires on them but the directions have have for the new one don't match the labels and colors on the old one.



    the old one has the following colours and labels



    RH - red wire (that goes to the furnace)

    W - white wire (that goes to the furnace)



    G - green wire that is a ground (part of 4 wires that go to AC)

    RC - red wire that has +12 volts (part of 4 wires that go to AC)

    Y - white wire that is part of 4 wires that go to the AC

    H - blue wire that is part of 4 wires that go to the AC



    I used a meter on the G and RC wire to verify that I have power



    Below is the instructions for the wires for the new thermostat



    HI-FAN - blue wire

    GND - black or green wire

    FAN - orange or tan

    COOL - yellow

    FURNACE - white

    +7.5 - red or red/white



    -------------------------------------------------------------------------------------------------------

    with the old thermostat the AC works but the furnace does not start at all....I replaced the relay on the furnace because if I bypass the relay the furnace motor does run...just replacing the relay didn't make the furnace run so I decided to get a new thermostat



    when I replaced the thermostat with the new one I used the following wiring but then nothing worked (not even the AC) - so I need some help wiring the new thermostat



    HI-FAN - the blue wire (H on the old one)

    GND - green wire (G on the old one)

    FAN - red wire (RH on the old one....I don't think this is correct)

    COOL - white wire from AC (Y on the old one)

    FURNACE - white wire from furnace (W on the old one)

    +7.5 - red wire from AC (RC on the old one)



    The old duo-therm by dometic has part number 3105058....if that helps at all.

    thanks

    Mike

  • Anonymous May 16, 2009

    I am trying to wire up a duo therm 3105058 A/C thermostat in an rv I recently purchased. The wires are no where near the color as listed in the earlier responses. They are 1 red , 1 white, 1 green, 1 light grey, 1 dark grey, & 1 blue. Does anyone know who to wire this up? The old one was already removed.

  • Anonymous Aug 18, 2012

    I looked everywhere for clarification on this mod All the tips have RW + RC jumpered with a "BLACK OR GREEN" wire ground going to them....that didn't make any sense electronically to me so I put together a schematic diagram and just installed the mod last night...it works perfectly in cool, heat, fan speeds, everything.http://burdick.home.digital.net/ke4ozd/R... RC and RW are unjumpered in mine since each could theoretically have a different power source, otherwise you could be working on one alone and the darn thing energize on you from the other units power source.

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  • Posted on Sep 13, 2011
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Red and white are positive and neg 12v
green is low fan
grey is high fan
yellow is cooling
blue is neg 12v(marked B-)

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  • Posted on May 31, 2008
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Generally on most thermostats R is the power to the thermostat, W is for heating, Y is for cooling, and G is for fan operation.

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  • Posted on Jun 11, 2020
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I was replacing a DUO-Therm 3105058 Rev A. very old Thermostat in a Coachman RV with 3106995.032 from Amazon. After looking all the information on the directions it was clear I would have to play a hit or miss on some of the wiring. Instead of using the same coding, such as RC, RH, G, Yellow and such. they used the function and I had to guess at some.
Here is the wiring I found worked:
There are 6 wires. One set of two wires (white On the W & red on the RH) and the set of 4 (yellow On the Y, green on the G, red on the RC and blue on the H). So to keep it simple the red on the RH went to the +7.5. The White on the W went to the FUR. HS/HP not used. the Yellow from the Y went on the cool. The green on the G went to the fan. The red on RC went to GND. and the Blue on H went to Hi fan.
So red (RH) of the 2 wire goes to +7.5
White (W) of the 2 wire goes to FUR.
Yellow (Y) to cool
Green (G) to fan
Orange or red from the RC lug goes to GND
Blue (H) goes to Hi Fan

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  • Posted on Aug 18, 2012
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I looked everywhere for clarification on this mod
All the tips have RW + RC jumpered with a "BLACK OR GREEN" wire ground going to them....that didn't make any sense electronically to me so I put together a schematic diagram and just installed the mod last night...it works perfectly in cool, heat, fan speeds, everything.
http://burdick.home.digital.net/ke4ozd/RVstat.jpg
RC and RW are unjumpered in mine since each could theoretically have a different power source, otherwise you could be working on one alone and the darn thing energize on you from the other units power source.

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  • Posted on Apr 20, 2010
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I am installing a therm from the old duo therm need the wiring diagram for the new one blue , y, white, bro, org where do they go

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