Staying cool in your RV during the summer is a direct result of regular air conditioner maintenance. Though there are both roof and basement AC units used by RV manufacturers, we will address the most common, roof mounted unit.
The first and most frequent item that needs attention are the filters; that screen the intake air at the AC unit, or if ducted, the ceiling intakes. These are the most common efficiency robbers and should be cleaned every couple of weeks during the season. Keeping these clean cannot be over stressed.
Always check your incoming A/C voltage when arriving at a new site and from time to time thereafter. This should be read while the air conditioner(s) are operating. Voltage of less than about 104 volts can reduce efficiency and do damage to the motors. This can be read and monitored using a simple plug-in A/C meter.
Staying cool in your RV requires the AC unit(s) be thoroughly serviced, at least every two years, depending on the environmental conditions your unit has been exposed to. This requires that the shroud covering the unit be removed. Should there be cracks or breaks in any part of the shroud, it should be replaced with new. Do not try to repair with glue. This shroud is a functioning part of the cooling process and must therefore be in good order. As the sun’s ultraviolet rays tend to deteriorate the plastic composite of these covers, I would recommend they be replaced every five to six years.
Caution: Unplug your unit from power prior to removing the AC shroud. Also be aware of the dangers of the charged capacitor(s). Once the covers have been removed, it will expose the evaporator and the condenser. These must be cleaned of debris to provide an unrestricted air flow. Caution must be used so as not to damage the thin metal fins. A fin comb is recommended for this job. Though there are many cleaning agents that can be used to remove the grease and dirt, I have found RV Voom cleaner to be very affective. Both the comb and the cleaning agent can be found at your local Camping World store.
Prior to re-installing the shroud, be sure to check the motors and apply a drop or two of machinery oil into the bearings. If the motor does not have remote oil ports, you may have to remove or loosen the rear mount to access the back bearing.
For as much as you have used water in the coil cleaning process, it may be wise not to power up the AC unit(s) for several hours. This will allow them to adequately dry should you have inadvertently got water in an electrical area.
This job is not necessarily a D.I.Y. project and may well be better done by a professional. The service is not that expensive and you would have the comfort of knowing it was done right. Enjoy staying cool in your RV.