Dometic Heating & Cooling - Page 3 - Recent Questions, Troubleshooting & Support

I take help from online websites that have this service like helping in repair some like reliable-store have instant help.. others are a bit slow which I don't prefer... rest is up to u.. U can also get free manuals

It sounds like your Dometic unit is not getting power despite the breaker being on. Unless the Dometic unit has an internal fuse to check, I would get out a volt/ohm meter and check to see: 1. Is there power coming out of the breaker that goes to the ac unit? 2. Is there power at the terminals of the ac unit? (You can sometimes remove a ceiling cover to access the contacts on the on off switch. Lastly is your RV hooked up to full power with two 110 volts on both legs beside the neutral and ground wire? If you are only feeding your RV with a standard 110 volt extension cord and using an adapter, that can mean half the circuits in your RV are energized while the other half 110 volt leg is not. You must energize the second leg by using a full 30 amp or 50 amp dual power cord. RV's are funny. They require two 110 volt legs with a neutral and a ground. The two 110 volt legs are both of the same phase. There is no 220 volts between the two hot legs as they are in phase. A volt meter between the when hot would read zero volts, while each hot leg to neutral would read 110 volts. Hope this helps.

Direct Replacement? You can go to any hardware store and replace with any thermostat. If you have Air conditioning make sure you get one AC compatible

Something has blown. Check fuses, connections, recheck all wiring connections. Don't know why the module and thermostat were changed but there may have been another original problem.

Take it back to where you bought and have repaired under warranty.

It sounds like your thermostat is stuck or your main contactor is stuck. Try shifting modes on your thermostat. If still stuck, try removing the thermostat, if the AC system did not stop it is your main contactor stuck and needs replaced. If your AC system stopped, it is your thermostat stuck and needs replaced.

I had the exact same problem, duo-therm AC unit on my RV the compressor ran continuosly, had to shut it off at the breaker. I too replaced the relay board thinking it was a stuck relay but the problem was still there. Good news is I found the problem. I took the cover off the thermostat panel inside the coach and found the thermostat wire marked "cool", was loose. I tightened this connection and the compressor shut down. Looks like the compressor and fan use seperated thermostat wires. Easy fix, and now I have a spare relay board that I didnt end up needing in the first place :-) Solution= check your thermostat connections at the terminal block inside your thermostat panel, they are probably loose.

Need to determine if it shuts off on satisfied thermostat, high pressure, low pressure, overload, etc. and inspection of condition and behavior of the system is needed for proper diagnosis. What exactly shuts off, air flow, cooling? does it turn back on and then off, as in short cycling? Make sure there is air flow thru the outdoor coil (radiator) and indoor coil for now. give a visual inspection to those coils making sure they are not obstructed or clogged, impeding air flow thru them and that the fans run. Only then can a technician diagnose the charge and performance of the unit. One can say it has a bad fan motor, there are at least two in the system, or that there is no air flow thru the radiators, condensor and evaporator, or that supply air flows directly on to the thermostat and thermostat satisfied on temperature, or, or.... who would do the servicing? when was the last maintenance/inspection on the system?

It may be major but I have found that most times the condenser fan has broken. It is plastic and shatters easily. You need to remove the cover to check it and connections.

on support of Dometic they require the SKU for archived manuals not the model number... Hope that helps.

It means that an error has occurred. If you have a 4 button comfort control. Follow these steps to reset:
To initiate a RESET, do the following in the order
listed:
1) Turn control on to ensure annunciator data and light are present. If data and light are present, continue to next step. Depress MODE switch to activate annunciator light.
Simultaneously depress the bottom two buttons (temperature UP and DOWN) and hold.
While holding these buttons down, depress the MODE button once and release.
Release the two buttons previously held down. Depress the MODE button once again.
At this time the light should extinguish, and the mode should register “OFF”. If not, repeat these steps.
Retest system ensuring that all functions are present
and operational.

If you have the five button comfort control. Turn the unit off and hold down the mode and zone buttons together. While holding them down, turn the thermostat back on. Hold the buttons down until an FF appears on the screen. Release the buttons and the display should return to normal. If not, try it again.

Probably low on freon. You may need to have a tech come and recharge it. This type of ac generally do not have a charge port.

Your system has a dual stage system for better efficiency. That is what the extra wires are. Either get the proper thermostat or decide to operate in single stage mode. High or low - you choose. Marking Wire Color Code Description Marking Wire Color Code Description R Red Power, 24 Vac transformer Rc Red Power from cooling, 24 Vac transformer Rh Red Power from heat, 24 Vac transformer C Black/Blue Common of 24 Vac transformer W White Primary heat cell relay E Brown Emergency heat relay Y Yellow Primary cool call relay Y2 Yellow Secondary cool call relay G Green Fan relay O Orange Change-over relay to cool relay B Blue Change-over relay to heat relay A Heat and cool active to any relay L Emergency heat active lamp X System malfunction lamp P Defrost control lamp

Check the Gas Valve if not the gas valve Check the Transformer For proper Voltage!