Cooper & Hunter mini split error code E1

Common causes

• A dirty or blocked outdoor coil.
• The outdoor fan not running or running slow.
• A service valve not fully open, or a restricted line set.
• A refrigerant overcharge.
• In heating mode: a badly restricted indoor airflow (dirty filter, frozen coil).

How to fix it yourself

Work through the checks below first; they resolve most cases. If they do not, the repair itself may need a technician.

1. Look at the outdoor unit: clear leaves, cottonwood fluff, snow or ice from the coil and make sure the fan can spin freely and nothing is stacked against the cabinet.
2. Confirm both service valves are fully open.
3. Pull the front panel and check the filters and the indoor coil. Dirty filters and a matted coil restrict airflow, and airflow problems trigger a surprising number of protection codes.
4. Reset the system: switch the breaker (or the outdoor disconnect) off, wait a full five minutes so the boards fully discharge, then switch it back on and restart from the remote.
5. Anything inside the refrigerant circuit (sensors are fine, but valves, compressors and leaks are not) needs EPA-certified refrigerant handling. That is a technician job.

Switch off power at the breaker before opening either unit. Capacitors in the outdoor unit hold a charge for several minutes after power is cut.

When to call a technician

If the coils are clean and the fans run, a technician needs gauges on the system to check the charge and the pressure switch.

Which Cooper & Hunter units show E1

This page applies to Cooper & Hunter Sophia, Astoria, Olivia, Dakota, Hyper Heat, Alice and MIA units. Cooper & Hunter's own documentation lists E1 as "High pressure protection", the same definition used across the Gree platform it is built on. If your unit shows a code with a different shape (for example a four-character code, or a plain number), it is from a different table; use the lookup with your exact code.

Where Cooper & Hunter shows this code

The code shows on the indoor unit's display in place of the temperature. If the display is off, press the Light button on the remote. Some models also count out the code as indicator blinks. E codes are system protections and faults, F codes are mostly sensor faults, H codes are outdoor and compressor protections, U codes are motor and valve faults, and P codes are power-supply faults.

Other Cooper & Hunter codes

Same part of the system as E1:

All Cooper & Hunter error codes

E1 on other brands

The same characters do not always mean the same thing. Check the brand on your unit.

• Pioneer E1 Communication error between indoor and outdoor units
• Blueridge E1 High pressure protection / Communication error between indoor and outdoor units
• Gree E1 High pressure protection
• Zone Air E1 Indoor room temperature sensor fault (open or short circuit)
• Daikin E1 Outdoor unit control board (PCB) failure
• Mitsubishi Electric E1 Remote controller control board fault
• Trane E1 Indoor room temperature sensor fault (open or short circuit) / Remote controller control board fault
• Heil E1 Communication error between indoor and outdoor units / High pressure protection
• ACiQ E1 Communication error between indoor and outdoor units / Indoor room temperature sensor fault (open or short circuit)