Mitsubishi Heavy aircon thermistor repair in Singapore
A Mitsubishi Heavy Industries temperature-sensor code can point to the thermistor, its connector and wiring, or the PCB input that reads it. We test the thermistor, wiring and PCB input, explain what failed and quote after diagnosis.
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Signs your Mitsubishi Heavy Industries aircon needs a thermistor check
These symptoms can involve a temperature sensor, but they can also come from its wiring, the control board, airflow or the refrigerant circuit.
A temperature-sensor error appears
A Mitsubishi Heavy Industries room, coil, pipe or outdoor sensor code identifies the circuit to test, not automatically the failed part.The unit short cycles or runs continuously
An incorrect temperature signal can make the system stop too early, run longer than expected or struggle to hold the set temperature.The temperature reading or icing looks unusual
A reading that does not match the room, repeated icing or unexpected protection can justify a sensor-circuit check.
Examples of Mitsubishi Heavy Industries systems we check
SRK residential wall-mounted systems
SCM residential multi-split systems
FDT / FDC cassette systems, with scope confirmed from the exact model
Model not listed
Send photos of the indoor and outdoor model labels, plus the error code or a short video of the symptom.
It may not be the thermistor
Before ordering a model-specific sensor, we check three problems that can create the same code or temperature behaviour.
Loose connector or damaged wiring
An open, shorted or corroded sensor harness can produce the same reading as a failed thermistor.PCB input fault
The sensor may measure correctly while the control board reads or processes its signal incorrectly.Airflow or refrigerant condition
A restricted coil, icing or abnormal refrigerant condition can create temperature symptoms without a failed sensor.
We match the code to the exact sensor circuit, inspect the connector and harness, measure the thermistor at the current temperature, and verify the PCB input. How a job runs, from first message to booking.
What is different on Mitsubishi Heavy Industries systems
MHI sensor meanings and parts are separate from Mitsubishi Electric even when the display looks similar. We verify the SRK, SCM or FDT family before testing or sourcing.
Mitsubishi Heavy Industries error codes related to thermistor problems
Open the group that matches where the code appeared on your unit.
Indoor unit or controller4 guides
Outdoor unit6 guides
- E37Outdoor heat exchanger sensor; Outdoor heat-exchanger temperature sensor open circuit
- E38Outdoor air temperature sensor; Outdoor-air temperature sensor open circuit
- E39Discharge pipe sensor; Discharge-temperature sensor open circuit
- E53Outdoor suction sensor; Suction-temperature or under-dome sensor open circuit
- E54High pressure sensor; Pressure-sensor open circuit
- E56Power-transistor temperature sensor fault
Whole-system faults2 guides
Codes that depend on the exact model14 guides
- E35Cooling high pressure protection
- E36Overheat of compressor
- E41 / RUN on / TIMER 4xPower transistor sensor error
- E59Trouble of outdoor unit
- RUN 1x / TIMER onHeat exchanger sensor 1 error; Indoor heat exchanger sensor 1 error
- RUN 2x / TIMER onRoom temperature sensor error
- RUN 3x / TIMER onHeat exchanger sensor 3 error
- RUN 7x / TIMER onRefrigerant insufficient, closed service valve, or heat exchanger sensor 1 error
- RUN keeps flashing / TIMER 1xOutdoor temperature sensor error; Outdoor air temperature sensor error
- RUN keeps flashing / TIMER 2xOutdoor heat exchanger fluid pipe sensor error; Outdoor heat exchanger sensor error
- RUN keeps flashing / TIMER 4xDischarge pipe sensor error
- RUN keeps flashing / TIMER 5xSuction pipe sensor error
- RUN on / TIMER 2xTrouble of outdoor unit
- RUN on / TIMER 5xOver heat of compressor
Codes can mean different things across model and system families. Every code is in the full lookup for this brand. Last reviewed 2026-08-21.
Is Mitsubishi Heavy Industries thermistor repair worth it?
Parts and timing
The correct Mitsubishi Heavy Industries sensor is model- and location-specific. Indoor and outdoor thermistors are not assumed interchangeable; we confirm the model, sensor position, part number and distributor lead time before you approve work.Our recommendation
Thermistor repair is usually a contained job when the sensor circuit is confirmed, the correct model-specific part is available and the rest of the system is healthy. Mitsubishi Heavy Industries systems commonly have a service life of 8-12 years. For a system over 10 years, major component failures usually favour replacement. Parts availability drops and efficiency loss compounds the repair cost.
If replacement makes more sense, we compare the repair quote with a suitable new system. See our aircon system replacement process.
Other Mitsubishi Heavy Industries repair checks
If testing rules out this part, these are the next checks on the same system.
Workmanship warranty
We stand behind the repair we carry out, and we are straight about the part of the cover we do not set ourselves.
Labour
30-day workmanship warranty. If the same fault returns from our repair, we come back and the labour is on us, with no second diagnostic visit fee.
Parts
Parts carry the distributor's warranty for that component, so the term varies by part. We tell you both terms before you approve the work.
Frequently asked questions about Mitsubishi Heavy Industries thermistor repair in Singapore
What are the signs of a Mitsubishi Heavy Industries thermistor problem?
How do you confirm a Mitsubishi Heavy Industries thermistor fault?
Is a Mitsubishi Heavy Industries error code enough to order the thermistor?
Should I repair or replace my Mitsubishi Heavy Industries aircon?
We cover all of Singapore. Find aircon services in your area.
Describe your situation
Tell us what’s going on. Symptoms, setup, photos, anything we should know. We’ll assess and come back with the right next step.
