Forum Discussion

aguablanco's avatar
aguablanco
Explorer
Jan 22, 2016

Thermostat Help Please

Decided to replace the Domestic analog thermostat with a new Honeywell RTH 111 digital non-programmable unit. Did my research on various websites and I was, or so I thought, ready to tackle this simple 30 minute job. Well, 2 hours later I am baffled and stumped. Here is where I am.
Old Dometic:
Red -7.5v
Brown-Fan
Blue -Hi Fan
White - Furnace
Yellow -AC
Green - Ground
Here is how I wired the new Honeywell:
Red-R/Rc with jumper
White-W
Yellow-Y
Brown-G
I taped off the ground as I was told it is not needed because the Tstat is battery powered. I also taped off the fan low as I really don't need that feature. As you may have guessed nothing works. I can hear a relay in the Tstat click when I switch on the heat slider but nothing happens. I am hoping someone here has a suggestion. Thanks in advance.
RichH

4 Replies

  • aguablanco's avatar
    aguablanco
    Explorer
    Jan 22, 2016
    rhagfo wrote:
    Got to ask why a non programmable? We set back at night and set up in the morning,mall automatic.


    Don't see any need for it. It is a 25' TT with 1 slide and we use the ceramic heaters more than the furnace. My main concern was the hysteresis and this Tstat addressed that concern adequately.
    RichH
  • rhagfo's avatar
    rhagfo
    Explorer III
    Jan 22, 2016
    Got to ask why a non programmable? We set back at night and set up in the morning,mall automatic.
  • aguablanco's avatar
    aguablanco
    Explorer
    Jan 22, 2016
    While I should have come here first, I did a general internet search and didn't realize that the diagram was for a Coleman Mach analog Tstat. Just went out and switched the wires as you suggested and, lo and behold, I have heat! Biscuit you are a great help. Thank you so much. I never would have thought that there was that type of difference in the Tstat wiring from one brand to another. After 20 years as a Millwright and 20 more as as a contractor my mechanical skills are fairly well established. Unfortunately, my electrical skills are sadly lacking.
    It seems that it is time for my medication.
    RichH
  • Old-Biscuit's avatar
    Old-Biscuit
    Explorer III
    Jan 22, 2016
    Not sure were/what you researched but the RED wire is NOT used and the Ground wire IS


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