Heat Controller HTS SERIES Functional Troubleshooting, Fault Htg Clg Possible Cause Solution

T h e Q u a l i t y L e a d e r i n C o n d i t i o n i n g A i r

R e s i d e n t i a l S p l i t - 6 0 H z R 4 1 0 A

R e v. : 0 3 A u g u s t , 2 0 1 2

Functional Troubleshooting

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

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