Mitsubishi Heavy — Faults, Diagnostics & Repair
Mid-tier Japanese brand found in many HDB and condo installs. SRK wall-mount units are reliable, but parts are less commonly stocked locally than Mitsubishi Electric or Daikin — older units may face longer repair lead times.
About Mitsubishi Heavy
Mitsubishi Heavy Industries (MHI) is a separate company from Mitsubishi Electric, though the shared name causes frequent confusion. MHI aircon units are a mid-range option in Singapore, offering solid build quality at a lower price point than the Starmex line. The SRK series is the most common residential model seen locally. Solid mid-range option with good build quality from a reputable Japanese manufacturer. More affordable than Mitsubishi Electric, but with a thinner local parts supply and less technician familiarity in Singapore.
At a glance
Common faults we handle
The faults Mitsubishi Heavy owners bring to us most — and the ones our technicians know inside out.
E1/E3 sensor fault
Thermistor issues common in older units — triggers error codes related to room or coil temperature sensing.
Compressor lockout
Outdoor unit shuts down under high ambient load or due to refrigerant issues. Requires on-site diagnosis to isolate the cause.
Drainage blockage
Standard tropical humidity issue. Drain pan and line clogging causes water leaks — same pattern seen across all brands in Singapore.
PCB failure
Control board issues in units beyond 7-8 years. Parts sourcing for MHI boards may take longer than for more common brands.
What we've learned servicing Mitsubishi Heavy
Patterns and tips from our technicians based on years of working with Mitsubishi Heavy systems.
MHI and Mitsubishi Electric are completely separate companies with different parts, different error codes, and different service networks. Mixing up the brand leads to wrong parts being ordered.
Parts for MHI are less commonly stocked locally than Mitsubishi Electric. Repairs on older units may take longer if parts need to be sourced.
SRK series units are reliable but less familiar to many local technicians. Make sure whoever services it knows the MHI-specific fault codes.
Filter cleaning every 2-4 weeks as with any brand. MHI coils in high-humidity environments need chemical cleaning when airflow drops.
MHI units are a good mid-range option — the build quality is solid, but the weaker local support network is the main trade-off vs Mitsubishi Electric or Daikin.
Repair or replace?
Age-based guidance for Mitsubishi Heavy units. The right answer depends on the fault, the unit's age, and what the part costs.
Popular Mitsubishi Heavy models
The series we see most in local homes — and the ones our technicians service regularly.
SRK wall-mount
The main residential line seen in Singapore. Compact wall-mount units for bedrooms and living rooms in HDB and condo installs.
FDT/FDC ceiling cassette
Commercial and larger residential installs. Recessed ceiling units for open-plan spaces where wall mounting is not practical.
SCM multi-split
Multi-room residential systems. One outdoor unit serves multiple indoor units — used in larger flats and condos.
Maintenance schedule
Staying on schedule prevents most of the faults listed above.
Mitsubishi Heavy FAQ
Related guides
Problem walkthroughs, parts explainers, and real diagnosis cases involving Mitsubishi Heavy units.
Case studies
Knowledge articles
Services & pricing
Once you know what's wrong, see what fixing it costs. Our rates are fixed by service type and confirmed before any work starts.
Need help with your Mitsubishi Heavy unit?
Send your model sticker and what changed. We'll advise the next diagnostic step before any work is approved.
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