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RV Air Conditioners and Furnaces
Rooftop AC brands, power draw, thermostat error codes, furnace lockouts and where to get parts.
Most RVs cool with a 13,500 or 15,000 BTU rooftop air conditioner and heat with a propane furnace, sometimes helped by a heat pump. This guide pulls the specs, codes and fixes from manufacturer manuals so you can figure out what you have and what's wrong with it.
QUICK ANSWER
The main rooftop AC brands are Dometic, Coleman-Mach (Airxcel), Furrion (Lippert) and GE. Most fit the standard 14 x 14 in roof opening. A 15,000 BTU unit runs about 13–14 A when cooling and up to 18–20 A in extreme heat, and its compressor can briefly pull 52–73 A when it starts. That's why one AC is about the limit on 30 A service or a small generator unless you add a soft start.
THE BRANDS
Who makes RV air conditioners
Dometic
Current US rooftop line: FreshJet 5 (13.5K, 15K and High Efficiency), R32 refrigerant, 10.5 in tall
Dometic says the FreshJet 15K is backward compatible with Penguin II models
Penguin II, Brisk II and Blizzard NXT no longer appear in Dometic's US listing, but parts are still sold
Coleman-Mach (Airxcel)
Mach 15, Mach 3 Plus, Mach 10, Mach 8 Plus, Quiet (NDQ) and heat pump models
Part-number prefix shows the profile: 38/48 medium, 35/45 low, 37/47 ultra-low
New variable-speed units: Everest VS-18, plus VS-14 heat pump models announced Aug 2026
Furrion (Lippert)
Chill HE 13.5K and 15K (R32)
Chill Cube 18K variable speed, with or without heat pump, ducted or non-ducted
Chill Cube 15K low-profile variable speed with heat pump
Thermostat, air distribution box and controller are sold separately
GE Appliances
RV rooftop ACs in the ARC, ARH, PLC and PLH families
Some older models, such as the ARH15AACB, are no longer made
A 2024 recall covered the soft start in many GE RV ACs (see Recalls below)
Also worth knowing: the Truma Aventa eco (13,500 BTU) is sold as a replacement for non-ducted rooftops, and Advent units turn up in some trailers. For vans, Dometic makes a 12V rooftop unit, the CoolAir RTX 2000.
POWER
How much power an RV air conditioner draws
Unit
Running amps (cooling)
Notes
Dometic FreshJet 5 15K (FJX5557M)
12.66–19.73 A
Built-in hard start
Coleman-Mach Mach 15
13.9 A
18 A in "desert" conditions; 16 A with heat strip
Coleman-Mach Mach 10
11.6–14.4 A
14.3–17.5 A in "desert" conditions
Truma Aventa eco (13.5K)
9.4–10.5 A
59 A for 150 ms at start-up
Any rooftop compressor at start
52–73 A for a moment
Dometic's locked-rotor rating for its 13.5K/15K units
30 amp vs 50 amp
30 A service is about 3,600 W, which usually runs one rooftop AC plus light loads
50 A service is two 120 V legs, about 12,000 W, enough for two or more ACs
Dometic calls for a 20 A time-delay breaker and 12 AWG wire per AC
Generators and soft starts
Dometic recommends at least a 3.5 kW generator for one AC and 5 kW for two, and notes generators lose power at altitude
Soft starts such as Micro-Air EasyStart, or Coleman-Mach's kit 1497-3601, cut starting current by up to 75%
That can let a 2,000 W generator, or 30 A service, start an AC it otherwise couldn't
REPLACING A UNIT
Will a new AC fit your roof?
The 14 x 14 opening
Most rooftop ACs fit the standard 14 x 14 in roof opening; Dometic specifies 14.3 x 14.3 in, plus or minus 0.1 in
Dometic requires 1.5 to 6 in from roof to ceiling
Low-profile units sit about 8–11 in tall, versus about 14 in for older designs
Ducted or non-ducted
Non-ducted units blow straight down through a ceiling assembly (air distribution box)
Ducted units feed ceiling ducts and need a ducted ceiling kit and return-air grille
Coleman-Mach part numbers ending in DQ are ducted; NDQ are non-ducted
Match your thermostat type too: Coleman-Mach 9 Series controls don't work with 8 Series parts
TROUBLESHOOTING
RV air conditioner error codes
Thermostat
Code
What it means
Dometic CCC2
E1
Lost communication with the AC control board(s)
Dometic CCC2
E2 / E3
Indoor temperature sensor open / shorted; fan still works
Dometic CCC2
E4
Outdoor sensor open (select models); heat pump locked out
Dometic CCC2
E5
Freeze sensor open; AC locked out, heat still works
Dometic CCC2
E7
No 120V AC power reaching the control boards
Dometic CCC2
E8 / E9
DIP switch setup conflict in a zone
Dometic single-zone LCD
E1–E5
Same meanings as the CCC2 codes above
Furrion Chill
E1 / E2
Indoor sensor / evaporator sensor fault
Furrion Chill
E3
Thermostat lost communication with the control box
Furrion Chill
lo
12V supply to the thermostat is too low
Coleman-Mach 9330
Er
Temperature out of range or remote sensor failed
Coleman-Mach 9330
GAS flashing
Backup furnace is helping the heat pump (not a fault)
From Dometic, Furrion and Airxcel thermostat manuals. Coleman-Mach doesn't publish an E-code list for its 9430 and Bluetooth thermostats, so be wary of code lists online that claim to. On Coleman-Mach zone systems, a dark green LED on the control board means low 12V control power, and the system won't run below 9.75 VDC.
BEFORE YOU CALL A TECH
Four checks for an AC that won't cool
1
Clean the filter
Dometic says to clean the return-air filter at least every two weeks of use, and never to run the AC without it.
2
Thaw a frozen coil
Ice forms with a dirty filter, closed vents or cool nights. Switch to fan only until it clears and keep at least two vents open.
3
Check power
Check the 120V breaker, shore-power or generator output and campground voltage. Low voltage is hard on compressors.
4
Wait 2 minutes
Compressors have a built-in restart delay of about 2 minutes. Cycling the power quickly can look like a failure.
FURNACES
RV furnaces: Suburban and Dometic (Atwood)
RV furnaces burn propane but run their blower and controls on 12V. The blower starts first, a sail switch proves there's enough airflow, and only then does the board try to light the burner. After 3 failed tries, the furnace locks out.
Suburban (Airxcel)
The sail switch closes at about 75% blower speed; weak 12V or lint on the blower keeps it open
Needs 10.5–13.5 VDC and 11–14 in WC propane pressure
Reset a lockout by turning the thermostat off, then on
Don't add air boosters to the ducts; Suburban says they make the sail switch act up
Check the outside vent for soot and insect nests; have it inspected yearly
Suburban's manuals don't list LED blink codes
Dometic DF series (formerly Atwood)
Board LED codes from Dometic's DF furnace manual:
LED
What it means
Steady on
Control board failure (hard lockout)
1 flash
Limit switch or airflow problem
2 flashes
Flame sense fault (hard lockout)
3 flashes
Failed to ignite (retries after 1 hour)
4 flashes
Voltage too high (16–17V)
5 flashes
Voltage too low (8–9V)
Reset: thermostat off for 10 seconds, then on. Repeat up to 3 times if there may be air in the propane line.
Suburban: (423) 775-2131 · Dometic: (800) 544-4881. Both makers recommend annual service by a qualified RV technician. Furnace parts by model: RV Furnace Guys.
HEAT PUMPS AND SAFETY
Heat pumps, heat strips and CO
Heat pumps
A heat pump AC heats efficiently in mild weather but loses output as it gets colder
Dometic's CCC2 switches to the furnace below 30°F outside and back above 35°F
A heat strip is supplemental heat only and doesn't replace a furnace
Carbon monoxide
Never cover or screen the furnace vent, and keep snow off it
Shut the furnace down if you see soot around the vent
Test the LP/CO alarm weekly in use; many must be replaced within 5 years
If the CO alarm sounds, get everyone to fresh air and call 911
RECALLS
RV air conditioner and furnace recalls
GE RV air conditioners: soft start (NHTSA 24E071)
Covers the ICM870 soft start in GE ARC, ARH, PLC and PLH rooftop ACs built June 1, 2022 – May 29, 2024, because of a risk of smoke or a thermal event
The fix is a replacement soft start in a metal enclosure. GE: 1-800-772-7262. Forest River filed a matching vehicle recall (24V771).
We found no 2020–2026 NHTSA equipment recalls for Dometic, Coleman-Mach, Furrion or Suburban rooftop ACs or furnaces (checked October 2026). Check your RV's VIN at nhtsa.gov/recalls.
WHERE TO BUY
Where to buy RV AC and furnace parts
Store
Type
AC and heating parts
Good for
Category specialist
Coleman-Mach (authorized retailer), Dometic, Furrion, Advent and GE units and parts
Matching parts to your model; free shipping on new rooftop ACs
Category specialist
Suburban and Dometic (Atwood) furnaces and parts by model: control boards, sail switches, gas valves, blowers
Furnace parts matched to your model
RV and trailer parts retailer
Dometic, Coleman-Mach and Furrion parts
Free staff answers to product questions
Local RV dealer or mobile tech
Service
Warranty work, furnace service
Annual furnace service, warranty claims
Store details checked October 2026. Have your model and serial number ready before ordering. Free help: Dometic support · Coleman-Mach library · Suburban documents · Furrion support · iRV2 forums
QUESTIONS
RV heating and cooling FAQ
What size AC opening do RVs use?
Most RV rooftop air conditioners fit a standard 14 x 14 inch roof opening. Dometic specifies 14.3 x 14.3 inches, plus or minus 0.1 inch, and 1.5 to 6 inches from roof to ceiling.
How many amps does an RV air conditioner use?
A 13,500 or 15,000 BTU rooftop unit typically draws about 12–14 amps while cooling and up to 18–20 amps in extreme heat. The compressor can briefly pull 52–73 amps at start-up.
Can I run two ACs on 30 amp service?
Usually not at the same time. 30 amp service is about 3,600 watts, which is roughly one rooftop AC plus light loads. A soft start can make it possible on some setups, but 50 amp service is the normal way to run two.
What generator do I need for an RV air conditioner?
Dometic recommends at least a 3.5 kW generator for one rooftop AC and 5 kW for two. With a soft start, many single ACs will start on a 2,000-watt inverter generator.
What does E1 mean on a Dometic thermostat?
On Dometic CCC2 and single-zone LCD thermostats, E1 means the thermostat lost communication with the AC control board, and the system shuts down. Check 12V power and the thermostat cable.
Why won't my RV furnace light?
Common causes are low 12V battery voltage, propane supply problems or air in the line, a blocked return or lint keeping the sail switch open, and a dirty or misgapped igniter. After 3 failed tries the furnace locks out; turn the thermostat off and on to reset.
NEED AN AC PART OR A NEW UNIT?
Start with your model number
RV AC Guys carries Coleman-Mach, Dometic, Furrion, Advent and GE air conditioners and parts, and will help you match the right one.
More: Coleman-Mach · Dometic AC · Refrigerators · Water heaters