AC concerns

[Mark-Roberta 051995]

Happy Sunday everyone. Here is one that I am unsure how to tackle. We have a ‘17 Landmark with 3 AC’s. While we were getting our new furniture installed at the dealership they had 1 of the AC’s on while working inside, not a big deal. When they were done, they unplugged the unit without turning off the 1 AC. When I arrived to pick it up my battery was very low as they left some 12 volts lights on so I had them plug me in. As soon as they plugged me in (30 amp) the 1 AC kicked on and I immediately turned it off. It kept running for about 5 minutes making some weird noises. It finally shutdown but I was concerned.
On Friday night while camping on shore power that same AC ran perfect until it hit the desired temperature and then made a lot of strange noise but running. I turned it off from the thermostat and it kept running for about 5 minutes. About 20 minutes later it started running again even with the thermostat off and I noticed it was pulling 23 amps based on my readout. I then found the correct breaker and shut it off altogether.
So - question
1. Why would it run with the thermostat turned off?
2. Could something have happened at the dealership based on my explanation?
3. Why doesn’t the thermostat send the E7 code showing loss of power when I flip the breaker ?
4. Why does the AC continue to run even when the temperature has been met - set it at 70 and gets to that coolness and it continues to run?


I tested the 2 other thermostats and only the bedroom one threw the code of E7 when I turned their breakers off. The second one did not.
1. Are the thermostats bad or is it in the AC?


Sorry for the long story I am concerned - on side note the labeling of the breakers are not as they appear. I have no breaker to turn off the microwave or living room TV. Amp readout shows normal after AC is stabilized.


Any help / suggestion is greatly appreciated

 

[Mark-Roberta 051995]

Anybody before I call Heartland Group?

Thanks, Mark

 

[danemayer]

My guess is something happened that probably damaged the circuit board on the A/C unit. Were there any thunderstorms in the area while at the dealer? Are all of your other electrical devices working ok?

"Strange noises" is too vague to comment on.

There is a normal shutdown for A/C units where the blower runs for a little after the thermostat is shut off or reaches the set point. Maybe 30 seconds or so.

 

[Mark-Roberta 051995]

Hey Dan,

I have a video of the noise but cannot load it as it is 1.97mb vs. the max. of 1.91mb.

I tested my other AC's and when they are being turned off or have met the required temperature per the thermostat it only takes about 5-10 seconds to shutdown. This one in particular takes about 1 minute, but then starts back up within 5 minutes or longer.
Also - when the breaker is turned off on the other AC's I get the E7 code on the thermostat which means loss of power. This one does not show this when breaker is off.

 

[danemayer]

Hey Dan,

I have a video of the noise but cannot load it as it is 1.97mb vs. the max. of 1.91mb.

I tested my other AC's and when they are being turned off or have met the required temperature per the thermostat it only takes about 5-10 seconds to shutdown. This one in particular takes about 1 minute, but then starts back up within 5 minutes or longer.
Also - when the breaker is turned off on the other AC's I get the E7 code on the thermostat which means loss of power. This one does not show this when breaker is off.

Neale sent me the video. You do have quite a noise there but I'm afraid I'm not sure what's going on. You may want to try Dometic Customer Service, although they'll probably point you back to the dealer.

 

[Lou_and_Bette]

Not sure if my experience will be of any help to you but here goes. My front AC started making a terrible noise and I thought it was going to seize up at any moment. I tried to find the source of the noise but was unable to do so because when I removed the cowling the noise wasn’t there. After trial and error, I found the source of the noise was a piece of the copper tubing from the coils, the one that stood straight up and was crimped on the end was “vibrating” against the cowling. Slight adjustment in position cured the noise. You might try removing the cowling and running the unit through a cycle and see if you can locate a source of the strange noise.

 

[Mark-Roberta 051995]

Glad your fix was quick. I removed my cowl on the roof and have a video of the canister make the noise. I have tried a few power shutdowns, swapped out thermostats and continue to have the same condition. The dealer is seeing about potentially sending a Tech. out to the campground and check a few things prior to me bringing in the unit to them.

 

[Mark-Roberta 051995]

UPDATE:

I have spoken with Heartland and they are sending my photos and video of noise from compressor. Heartland believes that Dometic will send out a new relay board / Transducer to me instead of taking it to the dealer since I can do the work quicker. I am hopeful I and everyone else has diagnosed it correctly