We are currently in southern Missouri and like most of the country it is HOT! The A/C runs all the time and we were wondering if there is some type of general maintenance we should do. The A/C was replaced two years ago so it is fairly new. We do not have a manual for it. Sure looking forward to days that we can open the windows!!
Really only a couple of things to do,, remove the cover from the top of the RV (with the power off) check for insect nests and use a water hose to back wash the coils. The interior filter (usually foam) needs to be washed in mild soap and dried.
This is the Tune-Up Program from Chris Bryant, RV Tech and frequent advisor here. When you have the Evaporator (the cold part) of the coils exposed you'll look down into the RV with the opposite of the view pictured above. This means you can get water down into the RV cleaning that coil. Chris has cautions in the link about that. Being a "Tool Time More Power" kinda guy, I rigged up a water deflector and actually hosed the evap coil clean. But using a garden sprayer, the kind you pump air pressure into, does a pretty good rinsing job and you can control the water easily.
The outcome on a 25-year-old Coleman Mach 13500 was so good that I didn't replace the unit as I'd thought I'd have to.
God Bless, jd
2003 Jayco Escapade 31A on 2002 Ford E450 V10 4R100