A MaxxFan is a 12-volt appliance with a few habits that catch owners out: the positive wire is black, the thermostat forgets its setting when the power goes, and the remote only works in line of sight. This guide collects what MaxxAir's installation and operating manuals say about power, wiring and the controls, and what that means for your battery.
How much power a MaxxFan needs
MaxxAir does not publish a running current for each fan speed. What its manuals do give is the minimum circuit each fan needs:
| Fan | Minimum circuit (MaxxAir) |
|---|---|
| MaxxFan, MaxxFan Plus, MaxxFan Deluxe (14 in x 14 in) | 12 V DC, 5 A |
| MaxxFan Mini Plus (14 in x 14 in bathroom fan) | 12 V DC, 2 A, fused |
| MaxxFan Dome and Dome Plus (6 1/4 in round) | 12 V DC, 2 A, fused |
| MaxxShade Plus (LED shade) | 12 V DC, 2 A, fused |
| MaxxFan Pivot | Not published on MaxxAir's product page; ask us |
MaxxAir also says to confirm the circuit can take the additional load and to use stranded wire of the proper gauge.
What that means for your battery
Because MaxxAir only gives the circuit rating, the honest battery math is a worst case: it assumes the fan pulls the full circuit rating the whole time. At low and middle speeds it will use less, so treat these as the shortest run times, not typical ones.
| Battery (assumed usable energy) | 14 in MaxxFan at its full 5 A | Mini Plus or Dome at its full 2 A |
|---|---|---|
| 100Ah LiFePO4: 100 x 12.8 V x 0.9 = 1,152 Wh | 5 A x 12.8 V = 64 W; 1,152 ÷ 64 = at least 18 hours | 2 A x 12.8 V = 25.6 W; 1,152 ÷ 25.6 = at least 45 hours |
| 100Ah AGM: 100 x 12 V x 0.5 = 600 Wh | 5 A x 12 V = 60 W; 600 ÷ 60 = at least 10 hours | 2 A x 12 V = 24 W; 600 ÷ 24 = at least 25 hours |
The usable-energy assumptions are ours: 90% of a lithium battery's rated capacity at 12.8 V, and 50% of an AGM's at 12 V. Remember the fan shares the battery with lights, the water pump and anything else running. Our RV solar and battery calculator adds the fan to the rest of your loads.
Wiring it correctly
- The black wire is positive. On the MaxxFan, Plus and Deluxe, MaxxAir says the fan's black wire, identified with a (+) tag, must connect to the vehicle's 12 V positive supply. The two fan wires are on the driver side of the fan. This is the most common wiring mistake.
- Use the connectors provided. The MaxxFan/Plus kit includes insulated 16-gauge connectors.
- Mini Plus and Dome use wire nuts and are marked "Pos. 12 VDC" and "Neg. 12 VDC". MaxxAir says their circuit must be fused.
- Disconnect main vehicle power before connecting the fan, MaxxAir says.
- The beep test. When power is restored, most MaxxFans beep to confirm a good connection, and remote models close their lids. The exceptions MaxxAir lists are the MaxxFan 4301K and 4401K and the Deluxe 5301K and 6401K. If a fan that should beep doesn't, recheck the connections and that 12 V is on.
- Built-in fuse. The MaxxFan, Plus and Deluxe have a self-resetting fuse on the circuit board in the ceiling unit. MaxxAir says to reset it by removing and re-applying power.
Installing from scratch? See replacing a 14x14 roof vent with a MaxxFan.
Using the controls
Keypad basics
- 4-speed exhaust models (MaxxFan 00A04301K/00A04401K and Deluxe 00-05301K/00-06401K) have a simple keypad: fan on, cycle through four speeds, fan off.
- Intake/exhaust models have an IN/OUT key. Pressing it slows the fan, pauses about two seconds and restarts in the other direction.
- Ceiling fan mode: with the fan running, close the lid and the fan keeps circulating air inside.
- Electric-lid models: press the + and - arrow keys together to open or close the lid without changing the fan.
Thermostat (Auto mode) on the 10-speed Deluxe
- Press AUTO for less than three seconds; three quick beeps confirm Auto mode and a green LED lights.
- The factory set point is 78°F. Hold the set key for more than three seconds to reset to 78°F, then use the arrow keys to adjust 1° per press.
- In Auto, the fan speeds up as the cabin warms. On electric-lid models, the lid opens and the fan runs as the thermostat calls for it, then the lid closes and the fan stops when the cabin cools to the set point.
- Auto mode defaults to exhaust; you can override it to intake.
- Power loss resets the thermostat to 78°F. If your battery disconnect is switched off between trips, re-check the set point.
Remote control (Deluxe 00-07000K/00-07500K, Plus 00-04500K)
- It's infrared. MaxxAir says it only works within line of sight of the fan, so not from outside the RV.
- On the Deluxe remote, the thermostat range is 29°F to 99°F; press both set-temperature keys together to switch between °F and °C.
- If the RV loses 12 V power, the lid can still be closed by hand with the knob at the ceiling.
Rain sensor (Plus 00-04500K)
- When it detects moisture, it turns off the fan and closes the lid. Pressing a key while it's still wet gives three beeps; restart with FAN ON once it dries.
- It has a disable function for running in light rain, which MaxxAir says to use with caution.
- It will not close a lid that was opened manually with the knob.
To compare which models have which controls, see MaxxFan Deluxe vs Plus vs standard.
When a MaxxFan won't turn on
MaxxAir's FAQ lists the usual causes in order: a blown fuse or tripped breaker, loose wiring connections, a faulty switch or remote, then motor or circuit-board failure. Check the fuse and the connections first, and for a fan that has just been installed, check the black (+) wire is on the positive side. For warranty help, MaxxAir's manuals give its technical department as 316-832-4357.
Cleaning and care
- Turn the fan off and remove its 12 V power before taking the screen out.
- The insect screen comes out by turning its four retaining knobs half a turn. Rinse it with water, with mild detergent for stubborn grime. Never run the fan with the screen removed.
- Clean all parts with mild soap and water only. MaxxAir lists ketones, esters, acetone, halogenated and aromatic hydrocarbons, amines and Loctite formulas as not compatible with the fan's plastics.
- With a MaxxShade fitted, don't run the fan with the shade closed; MaxxAir says the fan may overheat.
FAQ
Can I run a MaxxFan all night on batteries?
Usually. Even at the worst case of the full 5 A circuit rating, a 100Ah lithium battery covers about 18 hours of fan alone. Lower speeds use less.
Why did my thermostat setting change?
MaxxAir says removing 12 V power resets the thermostat to 78°F. Reset it after the battery has been disconnected.
Which MaxxFan turns on by itself when it gets hot?
Of the fans we carry, the 10-speed Deluxe models, which every MaxxAir source lists with a thermostat. (MaxxAir's 2025 catalog also marks the Plus models with one, but its current model table and Plus pages don't.) Our short answer on MaxxFan thermostats covers leaving pets in the RV. Every MaxxFan we carry is in the MaxxAir collection; found it cheaper elsewhere? We'll beat it.