Carrier aircon EH00 error code
Use this Carrier EH00 error code guide to decide when to stop resetting, what to capture, and what to check before parts are quoted.
What does Carrier EH00 mean?
Carrier EH00 is listed as iDU EEPROM malfunction in Wall-Mounted Split, Inverter Split rows such as 45MHHAC high-wall cooling only. The loaded row is source-backed by official diagnostic material. Confirm the exact model, series, or signal row before accepting a parts quote.
Indoor or outdoor PCB fault recorded by the source table.
Power supply, connector, fuse, EEPROM, or board-input problem.
Water ingress, surge damage, or wiring issue that must be ruled out before board replacement.
What to do now
Use these steps before another reset or parts quote.
Treat it as a fault signal
If EH00 returns or cooling is still abnormal, stop treating it as a simple reset issue.
Reset EH00 once
Capture the EH00 display first, then power-cycle once only and note whether the same fault returns.
Send these to us
EH00 error code, a clear display photo, Carrier model stickers, affected rooms, and reset result
What to check before repair
Use this split to separate safe evidence capture from the tests a technician should prove before quoting parts.
| You can check | Technician should confirm |
|---|---|
| Before resetting EH00, take a clear display photo. | Confirm which PCB or board input EH00 points to on the source row. |
| Capture the Carrier indoor and outdoor model stickers so the correct family row is used. | Check power supply, fuses, connectors, wiring, and board indicators. |
| Note whether one room, several rooms, or the whole system is affected, plus whether it returns after one reset. | Rule out water ingress, surge damage, and connected component faults before replacing the board. |
What changes the next step
These clues decide whether the first check is room-side, shared outdoor-side, refrigerant-side, source-table, or model-family confirmation.
| What you see | What it points to |
|---|---|
| Only one indoor unit shows EH00. | The affected room, indoor board path, wiring route, or local component should be checked first. |
| Several rooms or the outdoor unit show the same EH00 fault. | The shared outdoor side, power path, communication trunk, or refrigerant circuit needs priority checking. |
| The fault returns immediately after one reset. | Start with the source-row diagnostic branch before approving parts. |
| The model family is different from the row you found online. | Use the model or series filter first; same-looking codes can still belong to different diagnostic tables. |
| The model belongs to Wall-Mounted Split, Inverter Split rows such as 45MHHAC high-wall cooling only. | The loaded row is source-backed by official diagnostic material. Use the matching source row before quoting parts. |
PCB repair or replacement decision
Carrier EH00 should not jump straight to board replacement. Confirm power, connectors, wiring, and connected parts before deciding whether PCB repair or replacement is justified.
Power, fuse, connector, and water-ingress checks should happen before board replacement.
Connected motors, sensors, or valves can damage or confuse a PCB diagnosis.
Board availability and system age decide whether replacement is sensible.
Read next
Use these if the quote mentions the parts, checks, or repair path this code points to.
Other Carrier error codes
If the code you're seeing isn't EH00, jump to one of these or browse the full Carrier list.
Ready to get started?
Tell us what’s going on. Symptoms, setup, photos, anything we should know. We’ll assess and come back with the right next step.