Community Forums

dwhee · 11-14-2008, 07:18 AM

Hello all, I'm having trouble with both of our AC/HP units. We are taking the MH in today for work on these 2 units, but wanted to put a question out here to maybe help point the tech in the right direction. We have had the rear unit replaced about a year ago under warranty with a new unit (original had a coolant leak, or so I was told). The front unit was fine until a couple of weeks ago. The rear unit has acted different since we started using the AC this spring (3-4 months after replacement). When the rear unit would start (in AC mode), OCCASIONALLY we would hear the fan start and hear the compressor try to start but would not "kick in" and then would cycle off. A few moments later the whole cycle would start again sometimes with the AC starting correctly and cooling, sometimes not. Eventually, the air would work properly and cool correctly. The front unit has started doing the same thing in the heat pump mode (haven't seen it happen in AC mode, but the weather cooled quickly here). Additionally, the 2 year warranty period will run out this next January 3rd. Do you think that the best resolution will be to see if the 2 units need to be replaced or just repaired? Or, do you think that the temperature/humidity could have been such that the thermostat has malfunctioned?

Thanks, Dan

dwhee · 11-14-2008, 07:18 AM

Hello all, I'm having trouble with both of our AC/HP units. We are taking the MH in today for work on these 2 units, but wanted to put a question out here to maybe help point the tech in the right direction. We have had the rear unit replaced about a year ago under warranty with a new unit (original had a coolant leak, or so I was told). The front unit was fine until a couple of weeks ago. The rear unit has acted different since we started using the AC this spring (3-4 months after replacement). When the rear unit would start (in AC mode), OCCASIONALLY we would hear the fan start and hear the compressor try to start but would not "kick in" and then would cycle off. A few moments later the whole cycle would start again sometimes with the AC starting correctly and cooling, sometimes not. Eventually, the air would work properly and cool correctly. The front unit has started doing the same thing in the heat pump mode (haven't seen it happen in AC mode, but the weather cooled quickly here). Additionally, the 2 year warranty period will run out this next January 3rd. Do you think that the best resolution will be to see if the 2 units need to be replaced or just repaired? Or, do you think that the temperature/humidity could have been such that the thermostat has malfunctioned?

Thanks, Dan

Corvette Man · 11-14-2008, 09:28 AM

It could be the reostat which is a little black round thing on top of the roof unit. If it is bad you will see the black tar like substance comming out of it. There was a lot of talk on the Monaco forum 6-8 months ago. You might want to search for the link. Hope this helps. Monaco had a bunch of these over the last several years.

dwhee · 11-14-2008, 10:45 AM

Thanks, Man I'll check it out sounds like my problem

RV Wizard · 11-15-2008, 12:24 AM

dwhee,
the repair shop will have probably found the compressor motor starter and/or the start capacitors were bad and replaced them. Let us know what the fix was.

dmsatori · 11-15-2008, 03:04 AM

I had a similar problem (short cycling) I had one ac that did it from the day I got it. After two years of complaining at the factory, I finally got someone to listen.There was two of us there at the same time with the same problem.They got dometic to replace them. I later heard they were having more units with this problem. I never used the heat pump that much, so I don't know if did it there also. A dometic engineer tried moving the sensor to different locations,there authorised service did the same thing too. I always ended up with the same intermittent problem. hope this helps Dave

dwhee · 11-19-2008, 04:32 PM

A quick followup, the tech. was unable to get either unit to malfunction under normal circumstances. The only thing that he found was that the EMS was working properly in shifting power to the proper appliance when on 30 amp setting. Problem was that we were connected to 50 amp service. He stated that there must have been a voltage drop when I noticed the cycling?? Any ideas guys?
Thanks Dan

RV Wizard · 11-19-2008, 10:03 PM

Low voltage will definitely cause a problem. Did he test the capacitance of the start capacitor? He should have, just to be sure it is not marginal. Most techs do not have a tester but I have used mine for many years and find issues when others cannot. If it happens again find out the voltage under load.

dwhee · 11-20-2008, 02:53 AM

Thanks Wiz, I don't know what tests were done. What should the voltage under load be?
Dan

RV Wizard · 11-21-2008, 12:22 AM

107 volts under load is about as low a voltage you want to put your fan motors and compressors through. Do you have a Surge Guard? I highly recommend them for all your electrical protection.

dwhee · 11-21-2008, 03:18 AM

Thanks again Wiz, Yes I have a progressive industries hardwired 50 amp surge protector. I'll check to see if the voltage was at least 107 volts. I'm supposed to pick the rig up today hope that the voltage fluctuation was all that occurred.
Thanks again Dan

TXiceman · 11-21-2008, 03:54 AM

Appliances are supposed to operate on 120 volts + or - 10%...0r 108 volts to 132 volts.

What happens on low voltage is the amp draw goes up which is putting more heat into the motor winds which will break-down (deterioate)the winding insulation.