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CFBLACKTRIKE's avatar
CFBLACKTRIKE
Explorer
Jul 03, 2018

Dometic Thermostat Error code ??

We have 2015 Voltage Toyhauler with 3 A.C. units. Unit 3 is located in the garage area and only blows warm air. I replaced the capacitor and both the fan and compressor kicks on,,, and keep running but blows warm air. After running for just a minute the thermostatdisplays Error E7. This Error E7 indicates loss of 120 V. on module board .
However the A.C. unit keeps runnin !!! If I lost 120 V on all module boards how could the unit keep runnin ?? I thinkin i got multi problems here . with the A.C. unit blowing warm and a second problem with Error code showing. Sure could use any advive or suggests as to where to look for problem ???

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  • CFBLACKTRIKE's avatar
    CFBLACKTRIKE
    Explorer
    Jul 04, 2018
    Thank Ya Much for grim news !!! Kinda what I srmized but wishing for that magic trick to fix. This appears easy nough to change out the complete unit ,,, Looks like 4 very long bolts come up thru from the inside to hold the unit in place. Any other special precautions I should be aware of ?? I would plan for a new seal also . Any advice Greatly appreciated !!!!
  • dougrainer's avatar
    dougrainer
    Nomad
    Jul 03, 2018
    CFBLACKTRIKE wrote:
    Yepper,,, Up on the roof at the AC unit where the romex supply wire comes in. I read 188.8 V. The voltage reads on top of capacitor are 212V to the compressor . Keep i mind that is a capacitor voltage read.


    The Voltage TO the AC is supposed to be 115 to 125 volts AC. NOT anything else. If you have the 1 tstat(10 button CCC) for all 3 AC units it will read an error code if one of the units has lost 120 volts. You do NOT need to worry about the voltage PAST the input voltage. If the compressor runs and blows hot air the Upper unit needs to be changed. Doing anymore checkouts is just a waste of time. There is NO magic fix. Doug
  • CFBLACKTRIKE's avatar
    CFBLACKTRIKE
    Explorer
    Jul 03, 2018
    Yepper,,, Up on the roof at the AC unit where the romex supply wire comes in. I read 188.8 V. The voltage reads on top of capacitor are 212V to the compressor . Keep i mind that is a capacitor voltage read.
  • CFBLACKTRIKE's avatar
    CFBLACKTRIKE
    Explorer
    Jul 03, 2018
    The other thing that confuses me is ,,, even when i run the the other 2 AC units and get cold air ,,, the thermostat again shows Error E7 ,,, loss of 120 V. to module board BUT the other 2 AC units keep runnin fine. I am runnin these AC units one at a time.
  • time2roll's avatar
    time2roll
    Nomad
    Jul 03, 2018
    Yes sounds mechanical to the main unit if you have the compressor and blower fans running.
  • CFBLACKTRIKE's avatar
    CFBLACKTRIKE
    Explorer
    Jul 03, 2018
    Wow ,,,, Is it typical for these A.C. units to only last 3 years ??? Since this is a Toyhauler with 14 ft garage would i get better A.C. servive from a freestanding AC unit in garage ?
    I also second guest myself and triple checked my connections at capacitor ,,,, they were correct,,, so i connected a boost hard start capactor ,,, compressor kicks on but blows warm air
  • dougrainer's avatar
    dougrainer
    Nomad
    Jul 03, 2018
    I think you hooked up the new capacitor wrong. The fact the compressor runs and blows warm shows you need a new upper unit. It has either lost its coolant or the compressor is not pumping. Either way you need a new upper unit. I would replace the upper unit, then see if you lose the error code. Doug

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