Quick diagnosis
What this code is telling you
Most likely trigger
Refrigerant leak in copper lines
Recommended replacement
Pipe Thermistor Sensor Assembly
Diagnostic path
4 ordered checks
Part fit
Exact model number required
Safety first
Before opening the appliance
Unplug the appliance before removing panels or testing internal components. Do not bypass safety switches or live-test high-voltage, gas, refrigerant, or combustion components unless you are qualified to do so.
Read the full safety disclaimerRoot cause
Why the control reported this error
The mini-split control reports this code when a fan, sensor, communication, or refrigerant-system condition is not being confirmed. Start with refrigerant leak in copper lines, then rule out stuck electronic expansion valve (LEV) and faulty liquid pipe thermistor sensor before replacing pipe Thermistor Sensor Assembly.
Symptoms
What you may notice
- ✓Operation green light flashes twice
- ✓Indoor fan blows lukewarm air
- ✓Remote controller displays P8
Possible causes
Check the most likely causes first
- 1
Refrigerant leak in copper lines
Start here when it matches your symptoms.
- 2
Stuck electronic expansion valve (LEV)
- 3
Faulty liquid pipe thermistor sensor
- 4
Clogged air filter
Diagnostic sequence
Work through these checks in order
Stop when you find the fault. Do not perform a step that requires skills or live testing you are not qualified to do.
- 1
Check 1
Clean mesh filters in indoor unit head.
- 2
Check 2
Disconnect electrical power before opening panels. Measure thermistor resistance (kOhms) at plug connector and compare to chart.
- 3
Check 3
Verify LEV stepper motor operates when unit powers up.
- 4
Check 4
Replace liquid pipe thermistor sensor assembly.
Replacement part reference
Pipe Thermistor Sensor Assembly
Exact OEM part number
Model number required
Fitment note
The exact OEM part number varies by model and production revision. Verify the complete model number before ordering.
Verify the appliance model before ordering.
Manufacturers can use different parts under the same error code across model families and production revisions.
Where do I find my model number? →FixCodeDB may earn a commission from qualifying purchases made through affiliate links.
Common questions
Quick answers for this fault
What should I check first for P8?
Start with refrigerant leak in copper lines. If that checks out, continue through the diagnostic sequence above rather than replacing a part based on the code alone.
Does P8 always mean Pipe Thermistor Sensor Assembly is bad?
No. An error code identifies the condition the control detected, not a guaranteed failed part. Confirm the likely causes and wiring first. The exact OEM part number varies by model and production revision. Verify the complete model number before ordering.
When should I stop troubleshooting P8 myself?
Stop if the next step requires live electrical testing, sealed-system work, gas or combustion service, or any procedure outside your training. Unplug the appliance before removing panels or testing internal components. Do not bypass safety switches or live-test high-voltage, gas, refrigerant, or combustion components unless you are qualified to do so.
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