An RV that lives in Arizona ages differently. The sun is on the roof for more hours, the pavement is hotter under the tires, and the batteries sit in a compartment that can pass 120 degrees. None of this is a mystery to the people who make the parts. This guide collects what they publish about heat and what interval they put on each check, so the checklist at the end is theirs, not ours.
What the heat actually does
Rowley White RV, a Phoenix dealer, puts the whole problem in one sentence: “Prolonged temperatures above 100°F increase the risk of tire blowouts, shorten battery life, reduce air conditioner efficiency, strain refrigerators, dry out seals, and accelerate interior damage.” Each of those has a maker behind it with a number.
Roof and sealant
Sealant is the first thing to go. Rowley White: “Over time, sealants can dry out, crack, shrink, or pull away from seams.” Dicor, which makes most of the lap sealant on RV roofs, tells DiFlex roof owners that “Semi-annual inspection of the roof is suggested,” and for its Brite-Ply roofs says “Clean your roof at least four (4) times annually.” Alpha Systems says “Clean 2-3 times a year and inspect the caulking.” Lippert goes further for the whole coach: “Inspect seals monthly around the roof, windows, doors, and seams, then reseal gaps using RV-approved sealant to prevent water intrusion and structural damage.”
In Arizona the sun does the drying and the monsoon does the testing. Check before the rain, not after.
Tires
Two rules from the tire makers. Age: Michelin says “any tires in service 10 years or more from the date of manufacture, including spare tires, be replaced with new tires as a simple precaution even if such tires appear serviceable,” and that the “five-year inspection and ten-year replacement guideline applies from the manufacture date, whether the tire was in use or sitting in storage.” Pressure: the RV Industry Association says to “Check your tire pressure on every traveling day before hitting the road, since it should only be measured when tires are cold,” and Michelin adds “Do not reduce pressure when tires are hot.”
Parked tires need shade. Goodyear’s storage bulletin: “Stored tires should be protected against environmental effects such as sunlight, ozone, and other potentially damaging conditions.” North Phoenix Storage says the same in local terms: “shield them from the sun with tire covers, or store in a covered or enclosed space that keeps them shaded.”
House batteries
This is where the heat number is starkest. Trojan Battery: “For every 18° F (10° C) rise above room temperature (77° F or 25° C), battery life decreases by 50%.” A battery bay at 113 degrees is running at a quarter of its rated life.
For storage, Trojan says “Fully charge batteries before placing in storage.” Interstate says to “Check the water level and state of charge every 45-60 days” on flooded batteries. Lithium is easier: Battle Born says its batteries “do not need a trickle charge or maintenance while stored,” and its data sheet recommends charging to 100 percent and disconnecting them completely.
Rooftop air conditioner
Coleman-Mach says to “Clean the outside (condenser) coil at least once a year” and to “Clean or replace air filters as needed.” Furrion’s advice for the filter in summer is shorter: “Check every two weeks in peak season.” Coleman-Mach also warns about low voltage, which is common on a hot campground afternoon when every unit is running: the air conditioner “may be run safely between 105 volts and 125 volts. Do not operate the air conditioner outside of these parameters, as serious component damage may result.”
Refrigerator
An absorption fridge is a heat engine, and it loses ground in the heat. Dometic: “In hotter climates during summer period, we would expect the temperature to be around the 32°C (95°F) boundary.” Its support page on installation says “the venting, installation, clearance, and airflow of an absorption cooling unit refrigerator is imperative for proper operation.” Keep the outside vents clear and the RV level, and expect less from the fridge in July than in January.
Slides, seals and awnings
Lippert on slide-outs: “heat can soften rubber seals, causing more friction against the slide walls, and metal components may expand slightly, which can influence alignment or cause the slide to move more sluggishly.” The monthly seal inspection above covers slides too. For awnings, the National Weather Service in Tucson gives the number that matters: “Thunderstorm wind gusts in Arizona almost always exceed 40 mph.” Monsoon season, per the Phoenix office, “officially extends from June 15th through September 30th.” Retract the awning when you leave the site, every time, from mid-June on.
Water heater and generator
Suburban: “Check the anode rod every 6–12 months.” Dometic (Atwood) says to “Drain water heater at regular intervals (at least one time during they year).” Winnebago’s schedule: “Fresh water: sanitize every six months.” For the generator, Cummins Onan’s operator manual says “Exercise the generator set at least 2 hours each month if use is infrequent” and to “Run the generator set at approximately 1/2 rated power” while doing it.
The checklist
Every travel day, cold tires only: tire pressure.
Every two weeks in summer: AC filter.
Monthly: seals around roof, windows, doors, slides and seams (Lippert); generator exercise, two hours at half load (Cummins Onan); battery water level and charge on flooded batteries, every 45 to 60 days (Interstate).
Twice a year: roof inspection (Dicor); fresh water sanitize (Winnebago); anode rod (Suburban, every 6 to 12 months).
Yearly: AC condenser coil (Coleman-Mach); drain the water heater (Dometic).
Before summer storage: batteries charged and disconnected or on float; water heater drained; tires covered or the RV under cover; fridge emptied and vents clear; awning in; a walk of the roof seams so you know the starting point.
Every five years: tire inspection. At ten years from the date on the sidewall: new tires, whatever they look like (Michelin).
If a check turns up something you would rather not do on a roof in August, the techs on this site who list roofs, air conditioning, batteries or refrigerators in their own words are linked below.