Comfort-Aire HTS Series Split System,Two Stage, 2-5 Tons - Manual (Page 40)

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Installation, Operation & Maintenance HTS SERIES SPLIT SYSTEM Heat Controller, LLC
Functional Troubleshooting
Fault Htg Clg Possible Cause Solution
Main Power Problems
X X Green status LED off
Check Line Voltage circuit breaker and disconnect
Check for line voltage between L1 and L2 on the contactor
Check for 24VAC between R and C on DXM
Check primary/secondary voltage on transformer
HP Fault Code 2
X Reduced or no water flow Check pump operation or valve operation/setting
in cooling Check water flow adjust to proper flow rate
X Water t emperature out of range in
cooling
Bring water temp within design parameters
X
Reduced or no air flow
Check for dirty air filter and clean or replace
in heating
Check fan motor operation and airflow restrictions
Dirty air coil- construction dust etc.
Too high of external static. Check static vs blower table
X
Air t emperature out of range in
heating
Bring return air temp within design parameters
X X Overcharged with refrigerant
Check superheat/subcooling vs typical operating condition
table
X X Bad HP switch Check switch continuity and operation - Replace
LP/LOC Fault-Code 3
X X Insufficient charge Check for refrigerant leaks
Low Pressure/Loss of Charge X
Compressor pump down at start-
up
Check charge and start-up water flow
LT1 Fault - Code 4
X
Reduced or no water flow
Check pump operation or water valve operation/setting
Water Low Temperature
in heating
Plugged strainer or filter - clean or replace
Check water flow adjust to proper flow rate
X Inadequate anti-freeze level Check antifreeze density with hydrometer
X
Improper low temperature setting
(30°F vs 10°F)
Clip LT1 jumper for antifreeze (10°F) use
X Water t emperature out of range Bring water temp within design parameters
X X Bad thermistor Check temp and impedance correlation per chart
LT2 Fault - Code 5
Low Air Temperature
X
Reduced or no air flow
Check for dirty air filter and clean or replace
in cooling
Check fan motor operation and airflow restrictions
Too high of external static - check static vs blower table
X Air temperature out of range
Too much cold vent air - bring entering air temp within
design parameters
X
Improper low temperature setting
(30°F vs 10°F)
Normal airside applications will require 30°F only
X X Bad thermistor Check temp and impedance correlation per chart
Condensate Fault-Code
High Condensate Level 6
X X Blocked drain Check for blockage and clean drain
X X Improper trap Check trap dimensions and location ahead of vent
X Poor drainage
Check for piping slope away from unit
Check slope of unit toward outlet
Poor venting - check vent location
X Moisture on sensor Check for moisture shorting to air coil
Over/Under Voltage-Code 7
X X Under voltage
Check power supply and 24VAC voltage before and during
operation
(Auto Resetting)
Check power supply wire size
Check compressor starting. Need hard start kit?
Check 24VAC and unit transformer tap for correct power
supply voltage
X X Over voltage
Check power supply voltage and 24VAC before and during
operation.
Check 24VAC and unit transformer tap for correct power
supply voltage
Unit Performance
Sentinel-Code 8
X Heating Mode LT2>125°F Check for poor air flow or overcharged unit
X
Cooling Mode LT1>125°F OR
LT2< 40°F
Check for poor water flow, or air flow
Swapped Thermistor
Code 9
X X LT1 and LT2 swapped Reverse position of thermistors
X X Plugged air filter
X X Restricted return air flow
Replace air filter
Find and eliminate rectriction - increase return duct
and/or grille size
ECM Fault - Code 10
X X Blower does not operate Check blower line voltage
Check blower low voltage wiring
Blower operating with incorrect
airflow Wrong unit size selection
Wrong unit family selection
Wrong motor size
Incorrect blower selection
High Pressure
X Frozen water heat exchanger Thaw heat exchanger
X X Bad HPWS Switch Replace HPWS Switch