Quick answer
On our Summit units and the Glacier Pro 12V, an error code is a protection that fired: the unit shut itself down on purpose, and the code names a family with one safe first check, from power (E1, E4, E6) and the temperature probe (EC) to the fans (EF, E8), heat rejection (E2, H0) and the compressor and controller (E3, E7, E5, H2, H3). A code means the safety system worked; it is not a verdict on the machine. In our support data a power-off reset has not cleared an E1, an E5 or an EC-family code; one try suits EF, E3 and H2. On those units, a "13" or "I3" on the display is E1, misread.
| Code | What the unit is protecting against | First safe check | Stop and contact support when… |
|---|---|---|---|
| E1 | Supply voltage out of range, most often low voltage under compressor load | Charge the bank; read the remote's VOLTAGE button in Turbo | The bank is full, the chain checks out and E1 persists |
| E4 | Controller under-voltage | The same supply checks as E1 | The supply checks out and E4 persists |
| E6 | Controller over-voltage | Stop restarting; check what charges the bank | Right away |
| EC (EC, EC.1, EC1, EC2) | Lost temperature-probe signal | Probe plug fully seated in the correct socket | The plug is correct and EC returns |
| EF | Indoor (evaporator) fan failure | One reset; then re-seat every board connector | It returns after the sweep |
| E8 | Outdoor (condensing) fan failure | Clear debris; then re-seat the fan plug | It returns after both steps |
| E2 | Overcurrent | Clean condenser, clear outdoor fan | The condenser is clean and E2 returns |
| H0 | Over-temperature | As E2, plus clearance above the unit | Clean condenser, free airflow, H0 persists |
| E3 | Compressor blocking | One full power-off reset | It returns |
| E7 | Continuous blocking (persistent E3) | One reset, to rule things out | It returns |
| E5 | Short on the compressor's phase lines | One reset, as an exclusion step only (it has not cleared an E5 in our data) | After that one reset |
| H2 | Compressor phase failure | One reset; then control-terminal wiring tight | It returns, or turns into E5 |
| H3 (our support data, not the factory table) | Outdoor controller over-temperature | One reset and an airflow check, as exclusion only | It trips at startup again |
| Any other code; Glacier Pro 110V, Skyeline, Skyeline UM | Not covered by this table | Photograph the display and the model label | Before acting on this table |
Scope and safety. The factory table covers every Summit model (Summit 2, Summit 3, Summit Flex) and the Glacier Pro 12V; our check outcomes come from Summit 2 and Glacier Pro support threads. For the Glacier Pro 110V or a Skyeline mini-split, send support a photo of the display and the model label; the lineup chooser shows which unit is which. Isolate all power before opening any panel, and leave live measurements to a qualified technician. Stop and disconnect at a melted or discolored connector, damaged or melted cable insulation, a burning smell, smoke, or one joint noticeably hotter than the rest of the cable, and contact support with a power-off photo.
1. Power: E1, E4 and E6
E1 is the unit's supply-voltage protection (under- and over-voltage, most often low voltage as the compressor starts), E4 and E6 are the controller's own under- and over-voltage protections, and in our support data a reset has not cleared an E1, while fixing the battery and charging side has worked best.
For E1, charge the bank first, then read the remote's VOLTAGE button as the compressor starts in Turbo, then walk the four-step power chain in the wiring guide's §5 with power isolated; on a Summit 2 12V that chain includes a battery BMS rated 100A continuous. For frosty mornings, the cold-battery post explains why a cold pack sags sooner.
E4 gets the same supply checks; if the supply checks out and E4 persists, it is a support case, because the factory also lists controller damage. E6 means stop restarting the unit. Check the chargers and solar controller for a source that kept charging, correct it before reconnecting, and keep the unit isolated if there is heat or smoke. A battery's own over-voltage cutoff (14.6V on our 12V LiFePO4 batteries) is not the E6 trip point, and we publish no E6 trip voltage.
2. Temperature probe: EC, EC.1, EC1 and EC2
EC, EC.1, EC1 and EC2 are one temperature-probe family, and the first check, power isolated, is that the probe plug sits fully home in the correct socket on the indoor board, not the near-identical socket beside it; in our support data that re-seat cleared most EC codes without a part, while resets and mode changes never did.
On a Summit 2 the plug is 4-pin; then secure the small black probe above the return-air grille with its loop (the desert post's §5 shows it). On other models, check the probe sits in its intended position. Do the check even if the code cleared itself, and do not buy a new probe first. If EC returns, send support photos of the re-seated plug and the probe's position.
3. Fans: EF indoor, E8 outdoor
EF (indoor, evaporator fan) and E8 (outdoor, condensing fan) share one factory cause list, a loose connection, then a foreign object, then fan damage, so the checks run in that order, power isolated and hands clear of any fan that can turn.
EF: one reset; if it returns, re-seat every control-board connector one at a time, not just the fan plug. That full sweep is the fix that has worked most often for EF in our data. Tell support whether the indoor fan spins.
E8: clear leaves, debris or loose insulation from the outdoor fan, check that it turns freely once stopped without forcing it, and test. If E8 returns, re-seat the fan plug, looking for bent pins or corrosion. Fan voltage tests are technician work. The outdoor fan normally stays still until the compressor engages; a compressor that will not start belongs in §5.
4. Heat rejection: E2 and H0
E2 (overcurrent) and H0 (over-temperature) both list a dirty condenser and a failing condensing fan, so condenser cleanliness and outdoor airflow come before anything electrical; their remaining factory cause is a sealed-system issue only a technician can assess.
With power isolated, look for fins packed with dust and anything blocking the outdoor fan; our rooftop units need 15 in of clearance above the unit. The maintenance checklist has the cleaning steps. If the code returns, tell support whether it comes and goes or the compressor will not start.
5. Compressor and controller: E3, E7, E5, H2 and H3
E3, E7, E5, H2 and H3 are compressor and controller protections: the owner gets one power-off reset and, for H2, one power-isolated wiring check, and a code that returns is a support case, not a reason to keep resetting.
- E3 (blocking): one E3 case in our files cleared after a long power-off reset, so one try is worth it. If it returns, tell support whether the compressor runs; compressor-to-controller connections are checked once, power isolated, or by a qualified installer.
- E7 (continuous blocking, the persistent form of E3): one reset to rule things out, then support; the code alone does not prove the cause.
- E5 (a short on the compressor's phase lines): one reset, as an exclusion step only. In our data a reset has not cleared an E5 and re-seating the phase wires almost never has. An unstable supply can stress the controller, so tell support what powers the unit, and never run it from a vehicle starting battery.
- H2 (compressor phase failure; the indoor fan runs, the compressor and outdoor fan do not): a reset has cleared some. If H2 returns, isolate power and check the control-terminal wiring is tight; a loose yellow wire is a documented fix. If a reset turns H2 into E5, it is the same problem: report it and stop resetting.
- H3 (outdoor controller over-temperature; documented in our support data, not the factory table): every case tripped within seconds of startup, once on a 60°F day with the cover off, so it is not real heat build-up. A reset and an airflow check rule things out but did not clear it in our data. Send the battery chemistry, BMS rating and a startup VOLTAGE reading first: in one case a supply problem surfaced once the controller was replaced.
Resets. Disconnect all power, breaker off or cable unhooked, for about 30 minutes, the interval our support data uses. One try suits EF, E3 and H2; in our data it has not cleared an E1, E5 or EC-family code, and an H2 can return as E5. Never repeat a failed reset.
6. Display misreads and the VOLTAGE button
On our Summit units and the Glacier Pro 12V, a "13" or "I3" on the display is E1, because the seven-segment "E" reads as a "3" and the "1" as an "I"; an unprompted "13" is never a voltage, since the display shows one only after the remote's VOLTAGE button is pressed. A half-red or one-bar battery icon with it confirms E1. On those units, a code not in the table is almost always a misread, and a red icon alone is not automatically a fault: send a photo rather than guess. On a Glacier Pro 110V, do not assume a "2H" or "23" is H2 or E2; send a photo of the display and the model label.
On a Summit 2 the VOLTAGE button shows the voltage the unit receives (on a Summit 2 12V it also sets the low-voltage cutoff; see the wiring guide's §5). The Skyeline display is Celsius only.
7. What to send support
One message with a display photo, the model label, the battery type and BMS rating, a Turbo VOLTAGE reading and when the code appears lets support start on the cause. Use our contact page, and reply with each step's result.
| Send | Why |
|---|---|
| A photo of the whole display, icons included | Catches misreads |
| The model and voltage label | Scope; 12V checks do not apply to the 110V unit |
| Battery type (LiFePO4, AGM, lead-acid or starter), capacity, BMS continuous rating | The supply is the first suspect for E1 and E4 |
| The VOLTAGE reading in Turbo as the compressor starts | What the unit receives under load |
| When it appears: at startup, after hours, on hot afternoons, after a drive, after a fuse event | Narrows the family |
| Which parts run: indoor fan, outdoor fan, compressor | Separates fan and compressor codes |
| Any code change, such as H2 to E5 | The same problem, a new code |
| Every check already done, and its result | Nothing gets repeated |
| Power-off photos of any hot or damaged connector | Safety first |
No code at all? Not cooling: the 9-causes post. A 2026 unit cooling past the setpoint is designed behavior (the desert post explains the cycling logic). Shutting off without a code: the wiring guide. Water inside: the leaking-water post.
FAQ
What does E1 mean on an RV air conditioner?
On our Summit units and the Glacier Pro 12V, E1 is supply-voltage protection: the voltage the unit received was out of range, most often low as the compressor started. Charge the bank, read the remote's VOLTAGE button in Turbo, then walk the power chain in the wiring guide's §5, which on a Summit 2 12V includes a BMS rated 100A continuous. In our support data a reset has not cleared an E1.
What does the EC1 error mean?
On our Summit units and the Glacier Pro 12V, EC1 is part of the EC temperature-probe family (EC, EC.1, EC1, EC2): the unit is not getting a good signal from its temperature probe. With power isolated, confirm the probe plug is fully seated in the correct socket, not the look-alike beside it, and that the probe is secured in its intended position (above the return-air grille on a Summit 2). Re-seating has cleared most EC codes in our data; a reset has not.
How do I reset my 12V RV air conditioner?
Disconnect all power, breaker off or cable unhooked, for about 30 minutes, then test in Turbo. In our Summit 2 and Glacier Pro support data, one try suits EF, E3 and H2, and it has not cleared an E1, E5 or EC-family code. Do not repeat a reset that failed.
Why does my RV AC display show 13?
On our Summit units and the Glacier Pro 12V, a "13" or "I3" is E1 read on the seven-segment display: the "E" looks like a "3" and the "1" like an "I". It is not 13 volts; the display shows a voltage only after you press the remote's VOLTAGE button. On a Skyeline or the Glacier Pro 110V, send support a photo of the display.
When should I contact support about an error code?
After one round of safe checks for that code's family, or straight away for E6, an H2 that turns into E5, an H3 that returns at startup after one reset, or any sign of heat damage. Send the §7 checklist through our contact page.
Related reading
- 12V RV Air Conditioner Wiring Guide (2026)
- RV Air Conditioner Not Cooling in the Desert? (2026)
- 12V RV Air Conditioner Not Cooling? 9 Common Causes (2026)
- 12V RV AC Summer Maintenance Checklist (2026)
- LiFePO4 in the Cold: The 32°F Charging Cutoff (2026)
- Which OutEquipPro 12V RV Air Conditioner Is Right for You? (2026)
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Prices as listed October 18, 2026; verify on the product pages.
