Outdoor unit fan faulty
The E7 error code on Mitsubishi boilers indicates outdoor unit fan faulty. Symptoms include 2 noise has entered into power, 3 noise has entered into outdoor.
Mitsubishi E7 means: outdoor unit fan faulty. On this component the documented failure modes are motor blocked or inverter driver damaged, fan blocked, worn or its speed signal wrong or the fan has failed — short circuit or open circuit. You can safely reset the boiler once — if E7 returns, do not keep resetting. A qualified heating engineer should diagnose the root cause.
What Does E7 Mean
The E7 code is shown by the boiler’s control board when it detects outdoor unit fan faulty. The boiler then stops instead of continuing to run in that condition: the code is the appliance reporting a problem, not proof that the boiler is broken.
| What you see on the boiler |
|---|
| 2 Noise has entered into power |
| 3 Noise has entered into outdoor |
Common Causes
The first cause below is the one the Mitsubishi service literature publishes for this code (source: centriassistenza.org). The others are the failure modes documented for the same component on other boilers, confirmed by 7 different manufacturers.
| Cause |
|---|
| Motor blocked or inverter driver damaged |
| Fan blocked, worn or its speed signal wrong |
| The fan has failed — short circuit or open circuit |
Safety Warning
E7 involves electrical or pressure-related components. Do not attempt repairs without proper qualifications. Ensure the boiler is electrically isolated before any inspection. If you notice water leaks, unusual sounds, or pressure anomalies, contact a qualified heating engineer immediately.
Parts & Prices
Prices shown are indicative. Actual prices and availability vary by region.
Step-by-Step Diagnosis
1. Check for visible damage on the PCB — look for burnt components, corrosion, or water marks. 2. Check all wiring connections to the PCB are secure. 3. Try a power cycle — switch the boiler off at the mains for 30 seconds, then switch back on. 4. If the fault persists after power cycling, check the error code history for related faults. 5. Verify the mains voltage supply to the PCB is stable (230V ±10%). 6. Check the earth connection
How to Fix It
Check the fan turns freely, then check its connector, wiring and speed signal; replace the fan if the bearings are worn or the signal is absent.
Measure the resistance of the fan with a multimeter and compare it against the manufacturer’s resistance-versus-temperature table; replace it if it is open circuit, short circuit or out of range.
Refer to the Mitsubishi service documentation for the detailed procedure. Only a qualified engineer should carry out these repairs.
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Affected Models
Mitsubishi models that can display fault code E7:
| Model Family | Output Range | Frequency |
|---|---|---|
| All Mitsubishi models | — | Possible |
Frequently Asked Questions
Check the fan turns freely, then check its connector, wiring and speed signal; replace the fan if the bearings are worn or the signal is absent. According to the technical documentation, this is the first check on the list for E7.
E7 is not classified as a high-severity fault, so the boiler can be reset once. If E7 comes back, stop resetting: the underlying cause is still there and needs a qualified heating engineer.