Forum Discussion

ESDA's avatar
ESDA
Explorer
Aug 03, 2021

Dometic AC

I have a newer 2020 domestic A/C, which runs fine. However, the last couple times camping trips, it seems to not start up correctly once in a while. Usually, it runs fine cycling on and off as normal. In cooler periods, at night, and when it’s not as hot, it doesn’t seem to have any problems. However , it seems, on very hot days, in the morning, it will not start up. I replaced the thermostat with another one and it is doing the same thing. If I shut off the thermostat for a few minutes then turn it back on it will start. Also, if I remove the freeze sensor from the grill it will start right up. Any ideas.
  • Seon's avatar
    Seon
    Explorer II
    Aug 03, 2021
    A "Hard Start" capacitor may fix your problem.
  • MFL's avatar
    MFL
    Nomad II
    Aug 03, 2021
    You might try notifying the moderator, to move this thread to the tech section, to get more response.

    Jerry
  • jdc1's avatar
    jdc1
    Explorer II
    Aug 03, 2021
    Let's start with where you are at when this happened. Campground? It could be you are not getting the required voltage. The campground has to feed the whole place. In the late afternoon, there might be less of a draw from other campers.
  • pianotuna's avatar
    pianotuna
    Nomad III
    Aug 03, 2021
    Do check the voltage under load. If it is below 108 then do not run the air conditioner. I recommend a Kill-a-watt meter.
  • time2roll's avatar
    time2roll
    Nomad
    Aug 03, 2021
    ESDA wrote:
    Also, if I remove the freeze sensor from the grill it will start right up. Any ideas.
    Interesting.

    When it fails to start you mean you get nothing? No hum, no clicks? Like totally no power?

    I would start thinking it is the sensor or more likely the control board the sensor and thermostat connect to. Fairly easy to replace.
  • ESDA's avatar
    ESDA
    Explorer
    Aug 04, 2021
    It has happened a 2 different campgrounds. I have a surge/fault protector, and it shows no issues with the campground power.

    The a/c seems to operate fine. At night when it is cooler, it cycles with no problem. The issue always seems to start in the late morning as the temps outside start heating up. It just seems like the a/c is being told to start. It is not an issue that the a/c is trying to start but doesn’t.
  • Sagebrush's avatar
    Sagebrush
    Explorer
    Aug 04, 2021
    Probably a capacitor issue or low voltage. Its smart to always monitor your voltage, I want to see over 115 volts myself. You need an EMS set up if you want it automatic, surge protection is almost worthless. I just use a $11 plug in voltage meter in the kitchen and my eye balls. I'm cheap... low voltage is the biggest killer of A/C units IMO.
  • CavemanCharlie's avatar
    CavemanCharlie
    Explorer III
    Aug 05, 2021
    ESDA wrote:
    It has happened a 2 different campgrounds. I have a surge/fault protector, and it shows no issues with the campground power.

    The a/c seems to operate fine. At night when it is cooler, it cycles with no problem. The issue always seems to start in the late morning as the temps outside start heating up. It just seems like the a/c is being told to start. It is not an issue that the a/c is trying to start but doesn’t.


    Where is your thermostat located ? Could it be that the location is screwing up the thermostat and it's not getting a actual temp reading of the inside of the TT ?
  • prichardson's avatar
    prichardson
    Explorer
    Aug 05, 2021
    Is the temperature in the TT actually above the thermostat set point or are you going by how it feels? If it has not run for a while and you are starting to get active; it may feel warmer than it actually is.
  • ESDA's avatar
    ESDA
    Explorer
    Aug 07, 2021
    I am checking the actual temperature on the thermostat. I have it set for 74, and the thermostat is showing the actual temperature of 84. If I shut the thermostat off for about a minute and then reset it to cool, it will start the a/c. Also if I take the freeze sensor out of the fins and just leave it hanging, it will start right up.

About Travel Trailer Group

44,029 PostsLatest Activity: Jan 13, 2025