Midea M-Thermal Series - Page 71

M‐ThermalSplit  
70 201909
MideaM‐ThermalSplitServiceManual
Procedure

P5 


Watersideheatexchangerwaterinlet/
outlettemperaturesensorisloose
1

Yes
Ensurethetemperaturesensoris
connectedproperly
No

Watersideheatexchangerwaterinlet/
outlettemperaturesensorhas
short‐circuitedorfailed
2

Yes
Replacethetemperaturesensor
No

Waterpipingcontainsair
Yes
Purgeairfromthewatersystem
2

No

Thewaterflowrateisnotsufficient,
causedbycrushedorbentwaterpiping,
incorrectpumpspeedsetting,high
resistanceinwaterpipingorbroken
expansionvessel
4

Yes
Inspectthesystemandfixtheerror
No

ReplacehydronicboxmainPCB  

Notes: 
1. WatersideheatexchangerwaterinlettemperaturesensorandwatersideheatexchangerwateroutlettemperaturesensorconnectionsareportCN6on
thehydronicboxmainPCB(labeled11inFigure4‐2.1inPart4,2.2"MainPCBforHydronicSystem").
2. Measuresensor resistance.If the resistanceis toolow, the sensorhasshort‐circuited.Iftheresistanceisnotconsistentwith thesensor’s resistance
characteristicstable,thesensorhasfailed.RefertoPart2,1.2“HydronicBoxLayout”andtoTable5‐5.3inPart5,5.1“TemperatureSensorResistance
Characteristics”.
3. RefertotheM‐ThermalSplitEngineeringDataBook,Part5,15“SPECIALFUNCTIONS”.
4. Checkwaterpressureonthemanometer.Ifthewaterpressureisnot>1bar,waterflowisinsufficient.RefertoFigures2‐1.7and2‐1.8inPart2,1.2
“HydronicBoxLayout”.


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