What does Mitsubishi Heavy Industries E49 mean?
Mitsubishi Heavy PAC / KX E49 is listed as low-pressure fault in Cassette, Ducted, VRF rows such as Inverter PAC FDC VA / VN / VNA / VNP / VS / VSA / VNX / VSX outdoor units, Inverter KX KX4 / KX6 / KXRE6 / KXZE1 / KXZPE1 / KXZRE1 systems. This meaning comes from the manufacturer's own diagnostic material. Confirm the exact model, series, or signal row before accepting a parts quote.
Low refrigerant, active leak, restriction, or abnormal pressure reading.
Dirty condenser, weak outdoor fan, blocked airflow, or high-load operation.
Pressure sensor, expansion path, or compressor protection after readings are taken.
What to do now
Use these steps before customer action, gas work, a pressure check, or parts quote.
Stop using the unit if E49 returns
Stop using the unit if E49 returns with weak cooling, frost, hissing, or outdoor-unit tripping.
No manufacturer reset steps listed for E49
Capture the complete E49 display and model stickers first. The manufacturer lists no customer reset procedure; do not treat a generic power-cycle as manufacturer guidance.
Send these to us
E49 error code, a clear display photo, Mitsubishi Heavy PAC / KX model stickers, affected rooms, operating state when the code appeared, and cooling-loss timeline and any recent gas top-up
Guidance for your model
Notes that match the code to your exact model. Electrical, refrigerant, wiring, resistance and component checks are for a technician.
| Detail | What it says |
|---|---|
| Diagnostic note | Stop the system if it repeatedly trips. Have a qualified technician check airflow, service valves, sensors, operating pressures, refrigerant charge, and leakage before resetting it. |
| Singapore / model note | Official current MHI commercial error-table row E49. PAC/KX family applicability and display detail are cross-checked against MHI Service Support Handbook PDF pages 32, 38. Confirm the installed model family and its own service manual before parts replacement; no Singapore-only model mapping is claimed. |
- Detail
- Diagnostic note
- What it says
- Stop the system if it repeatedly trips. Have a qualified technician check airflow, service valves, sensors, operating pressures, refrigerant charge, and leakage before resetting it.
- Detail
- Singapore / model note
- What it says
- Official current MHI commercial error-table row E49. PAC/KX family applicability and display detail are cross-checked against MHI Service Support Handbook PDF pages 32, 38. Confirm the installed model family and its own service manual before parts replacement; no Singapore-only model mapping is claimed.
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 taking any system action on E49, take a clear display photo. | Match E49 to low-pressure, high-pressure, leak, or refrigerant-cycle protection. |
| Capture the Mitsubishi Heavy PAC / KX indoor and outdoor model stickers so the correct family row is used. | Measure operating pressures, coil temperatures, airflow, and outdoor fan condition. |
| The manufacturer lists no customer reset procedure for this code. Note whether one room, several rooms, or the whole system is affected. | Leak-check or pressure-test before recommending another refrigerant top-up. |
- You can check
- Before taking any system action on E49, take a clear display photo.
- Technician should confirm
- Match E49 to low-pressure, high-pressure, leak, or refrigerant-cycle protection.
- You can check
- Capture the Mitsubishi Heavy PAC / KX indoor and outdoor model stickers so the correct family row is used.
- Technician should confirm
- Measure operating pressures, coil temperatures, airflow, and outdoor fan condition.
- You can check
- The manufacturer lists no customer reset procedure for this code. Note whether one room, several rooms, or the whole system is affected.
- Technician should confirm
- Leak-check or pressure-test before recommending another refrigerant top-up.
What changes the next step
These clues decide whether the first check is room-side, shared outdoor-side, refrigerant-side, listed-meaning, or model-family confirmation.
| What you see | What it points to |
|---|---|
| Only one indoor unit shows E49. | The affected room, indoor board path, wiring route, or local component should be checked first. |
| Several rooms or the outdoor unit show the same E49 fault. | Prioritise the shared outdoor side, pressure conditions, airflow, and refrigerant circuit. |
| Cooling is weak, frost appears, or the outdoor unit trips under load. | Pressure, airflow, leak, and condenser checks should come before another top-up. |
| 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 Cassette, Ducted, VRF rows such as Inverter PAC FDC VA / VN / VNA / VNP / VS / VSA / VNX / VSX outdoor units, Inverter KX KX4 / KX6 / KXRE6 / KXZE1 / KXZPE1 / KXZRE1 systems. | This meaning comes from the manufacturer's own diagnostic material. Match the code to your model's listing before parts are quoted. |
- What you see
- Only one indoor unit shows E49.
- What it points to
- The affected room, indoor board path, wiring route, or local component should be checked first.
- What you see
- Several rooms or the outdoor unit show the same E49 fault.
- What it points to
- Prioritise the shared outdoor side, pressure conditions, airflow, and refrigerant circuit.
- What you see
- Cooling is weak, frost appears, or the outdoor unit trips under load.
- What it points to
- Pressure, airflow, leak, and condenser checks should come before another top-up.
- What you see
- The model family is different from the row you found online.
- What it points to
- Use the model or series filter first; same-looking codes can still belong to different diagnostic tables.
- What you see
- The model belongs to Cassette, Ducted, VRF rows such as Inverter PAC FDC VA / VN / VNA / VNP / VS / VSA / VNX / VSX outdoor units, Inverter KX KX4 / KX6 / KXRE6 / KXZE1 / KXZPE1 / KXZRE1 systems.
- What it points to
- This meaning comes from the manufacturer's own diagnostic material. Match the code to your model's listing before parts are quoted.
Pressure, leak, or airflow decision
Mitsubishi Heavy PAC / KX E49 needs measured pressure, airflow, and leak evidence before gas work is approved. Replacement only becomes serious when the leak, compressor, or coil repair is uneconomical.
A top-up alone is poor value if the leak source is not found.
High-pressure faults often come from airflow, condenser, fan, or overcharge conditions.
Coil leaks or compressor-related findings can shift older systems toward replacement.
Mitsubishi Heavy Industries E49 questions
What does the Mitsubishi Heavy Industries E49 error mean?
Can I fix a Mitsubishi Heavy Industries E49 error myself?
Is it safe to keep running the aircon with an E49 error?
What causes a Mitsubishi Heavy Industries E49 error?
Will a Mitsubishi Heavy Industries E49 error need a repair or a full replacement?
What should I send a technician about a Mitsubishi Heavy Industries E49 error?
Where to go next
Confirm the fault
Share the error code, model number and symptoms so we can assess the likely cause.
Not the right code?
Browse the full Mitsubishi Heavy Industries list or check a few codes in the same fault category.
Read next
Use these if the quote mentions the parts, checks, or repair path this code points to.