Heat Controller HTV, HTH, HTD Functional Troubleshooting, Htv/Htd/Hth Series, Heat Controller, Inc

Installation, Operation & Maintenance HTV/HTD/HTH SERIES Heat Controller, Inc.

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 CXM/DXM'
				Check primary/secondary voltage on transformer.
		X	Reduced or no water flow in cooling	Check pump operation or valve operation/setting.
				Check water flow adjust to proper flow rate.
		X	Water Temperature out of range in cooling	Bring water temp within design parameters.
HP Fault				Check for dirty air filter and clean or replace.
Code 2	X		Reduced or no air flow in heating	Check fan motor operation and airflow restrictions.
High Pressure				Dirty Air Coil- construction dust etc.
				Too high of external static. Check static vs blower table.
	X		Air temperature 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	X	X	Insufficient charge	Check for refrigerant leaks
Code 3	X		Compressor pump down at start-up	Check charge and start-up water flow.
Low Pressure / Loss of Charge
				Check pump operation or water valve operation/setting.
LT1 Fault	X		Reduced or no water flow in heating	Plugged strainer or filter. Clean or replace..
				Check water flow adjust to proper flow rate.
Code 4
	X		Inadequate antifreeze level	Check antifreeze density with hydrometer.
Water coil low	X		Improper temperature limit setting (30°F vs	Clip JW3 jumper for antifreeze (10°F [-12°C]) use.
			10°F [-1°C vs -2°C])
temperature limit
	X		Water Temperature out of range	Bring water temp within design parameters.
	X	X	Bad thermistor	Check temp and impedance correlation per chart
				Check for dirty air filter and clean or replace.
LT2 Fault		X	Reduced or no air flow in cooling	Check fan motor operation and airflow restrictions.
Code 5				Too high of external static. Check static vs blower table.
Air coil low		X	Air Temperature out of range	Too much cold vent air? Bring entering air temp within design parameters.
		X	Improper temperature limit setting (30°F vs	Normal airside applications will require 30°F [-1°C] only.
temperature limit			10°F [-1°C vs -12°C])
	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		X	Poor drainage	Check slope of unit toward outlet.
Code 6				Poor venting. Check vent location.
		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 restriction. Increase return duct and/or grille size.
				Check power supply and 24VAC voltage before and during operation.
Over/Under	X	X	Under Voltage	Check power supply wire size.
Voltage Code 7				Check compressor starting. Need hard start kit?
(Auto resetting)				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	X		Heating mode FP2>125°F [52°C]	Check for poor air flow or overcharged unit.
			Cooling Mode FP1>125°F [52°C] OR FP2<
Code 8		X		Check for poor water flow, or air flow.
			40ºF [4ºC])
No Fault Code Shown	X	X	No compressor operation	See "Only Fan Operates".
	X	X	Compressor overload	Check and replace if necessary.
	X	X	Control board	Reset power and check operation.
	X	X	Dirty air filter	Check and clean air filter.
Unit Short Cycles	X	X	Unit in "test mode"	Reset power or wait 20 minutes for auto exit.
	X	X	Unit selection	Unit may be oversized for space. Check sizing for actual load of space.
	X	X	Compressor overload	Check and replace if necessary
	X	X	Thermostat position	Ensure thermostat set for heating or cooling operation.
	X	X	Unit locked out	Check for lockout codes. Reset power.
Only Fan Runs	X	X	Compressor Overload	Check compressor overload. Replace if necessary.
	X	X	Thermostat wiring	Check thermostat wiring at heat pump. Jumper Y and R for compressor operation
				in test mode.
	X	X	Thermostat wiring	Check G wiring at heat pump. Jumper G and R for fan operation
	X	X	Fan motor relay	Jumper G and R for fan operation. Check for Line voltage across BR contacts.
Only Compressor Runs
	X	X		Check fan power enable relay operation (if present).
	X	X	Fan motor	Check for line voltage at motor. Check capacitor.
	X	X	Thermostat wiring	Check thermostat wiring at heat pump. Jumper Y and R for compressor operation
				in test mode
				Set for cooling demand and check 24VAC on RV coil and at CXM/DXM board.
		X	Reversing valve	If RV is stuck, run high pressure up by reducing water flow and while operating
				engage and disengage RV coil voltage to push valve.
Unit Doesn’t Operate		X	Thermostat setup	Check for ‘O’ RV setup not ‘B’.
		X	Thermostat wiring	Check O wiring at heat pump. Jumper O and R for RV coil ‘click’.
in Cooling
				Put thermostat in cooling mode. Check 24 VAC on O (check between C and
		X	Thermostat wiring	O); check for 24 VAC on W (check between W and C). There should be voltage
				on O, but not on W. If voltage is present on W, thermostat may be bad or wired
				incorrectly.

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