New AC problem

[Miamikeith]

Hi all. Newbie here. Been living in my 31’ Classic last couple of years. Recently had to replace my 13,500 Duotherm Penguin with a new 15,000 Penguin AC. I think there is a problem with the unit and dealer is telling me it’s ok. Here’s the problems, hopefully someone can help.

Unit cycles repeatedly. Come on for a minute or so shuts off comes back on and this repeats several times before it stays on. Seems like compressor isn’t kicking in on the recycling until at some point it does and then the unit stays on and cools. Sometimes the off cycle is just a few seconds and other times it 30 seconds or more.

Also have had it continue to cool trailer down to 69-70 degrees when thermostat is set to 78. Unit just seems to want to run and not shut off.

This is driving me crazy so any help would be GREATLY appreciated.

Thanks in advance.

Keith

[Miamikeith]

Thanks for all the replies. It’s 30 amp. Only other thing possibly running would be water heater but doubt that’s always running same time as AC. Dealer/installer has been pretty good so far. I’ll give them a call again and go over your suggestions/advice. Today I had unit set to 78 while I was at work. Got home around 7:30 temp outside high 80’s. Temp in trailer was 72 and AC running. I had to raise thermostat to 80 before it would kick off. I left it at 80 for about 2hours then dropped it to 75 just before bed. Unit kicked in with high fan no compressor for about a minute. Shut off for about 45 seconds came back on Wirth high fan no compressor again for about a minute and shut off again. 3rd time came on with low fan then compressor kicked in and it’s behaving normally now. Cooled off trailer shut down. Was off about 15-20 minutes and just came back on. No cycling this time. Hopefully with y’all’s suggestions dealer may have a direction to go to resolve this once and for all. Thanks again

[Boband4]

30 amp or 50 amp trailer service? If 30, and other items such as the water heater, microwave, or coffee maker cycle on it could be an amp draw/low voltage problem. Ensure all the other appliances are off and see if the problem continues.

[badsix]

I'm by far no A/C expert, but when I installed my soft start kit the instructions said that cycling the A/C on and off was very hard on the unit. something about head pressure needs to have time to normalize or something.
Jay D.

[allen8106]

colliehauler wrote:
I thought the same thing about the thermostat, but I'm not a HVAC person. I would also wonder if the A/C vent is blowing on the thermostat causing erratic behavior.

This happens in our bedroom. The AC vents out 3 sides. If I don't close the one on the side that vents towards the T-stat then it cycles needlessly.

[ndrorder]

If you think it is the thermostat turning on and off causing the cycling, just adjust the thermostat to well below the air temperature and see if the AC stays running or cycles as before.

There would be several sensors both pressure and thermal in a residential AC that would cause this kind of cycling. The problem is, there isn't enough information on the dometic page to see what the choices are.

May be a case of run it like you stole it until the warranty runs out then worry if overuse reduced its lifespan.

[ksg5000]

Doesn't sound normal to me. I would have polite conversation with the installer and let him know that you expect him to re-examine/test his installation. Be polite but make it clear that if the issue isn't resolved your going to take the rig to an independent installer who will evaluate/fix the issue and you will expect him/her to reimburse you for the expense. No rants etc - just let him/her know what you expect.

[newman_fulltime]

Chris Bryant wrote:
Sounds like an installation problem to me- recirculating air, inadequate airflow...
Regardless, that is not normal, and not good for the unit. Bad part is unless you get some goodwill gesture, Dometic isn’t going to cover bad installation.

I was thinking the same thing I am wondering if they set the dip switches correctly

[Chris_Bryant]

Sounds like an installation problem to me- recirculating air, inadequate airflow...
Regardless, that is not normal, and not good for the unit. Bad part is unless you get some goodwill gesture, Dometic isn’t going to cover bad installation.

[trail-explorer]

Miamikeith wrote:
Installer says that the constant repeated cycling is not an issue. That some units do that. Seems abnormal to me.

I don't think it's normal either.

Seems like the installer is saying that because he isn't willing to troubleshoot and fix the problem, or replace the unit again.

[Miamikeith]

Thanks for the feedback. New thermostat was installed with AC. Also installed new breaker as old one was heating up. Installer says that the constant repeated cycling is not an issue. That some units do that. Seems abnormal to me.

[cavie]

colliehauler wrote:
I thought the same thing about the thermostat, but I'm not a HVAC person. I would also wonder if the A/C vent is blowing on the thermostat causing erratic behavior.

Nor if it has a period of staying on.:)

[colliehauler]

I thought the same thing about the thermostat, but I'm not a HVAC person. I would also wonder if the A/C vent is blowing on the thermostat causing erratic behavior.

[prichardson]

My first suspect would be the thermostat.

[DutchmenSport]

Is the original or old thermostat really compatible with the new air conditioner?

Also, most newer air conditioners run in such a way that once they shut off, there is a delay before the cooling compressor will turn on again. Depending on the air conditioner, it could be as long as a 2 minute wait. But, during that wait time, the fan usually does not turn on either.

It sounds to me like there is a miss reading coming from the wall thermostat. If it were mine, I'd start troubleshooting there. The air conditioner gets its command signals to turn on, turn off, run on fan, reach it's temperature and turn off, all from the thermostat. The air conditioner, if it were just plugged in and wired with no thermostat, it would just run and run and run. It's the thermostat that controls on-off commands.