Heat Controller HTH, HTV, HTD manual Performance Troubleshooting

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

Performance Troubleshooting

Performance Troubleshooting	Htg	Clg	Possible Cause	Solution
	X	X	Dirty filter	Replace or clean.
				Check for dirty air filter and clean or replace.
	X
			Reduced or no air flow in heating	Check fan motor operation and airflow restrictions.
				Too high of external static. Check static vs. blower table.
				Check for dirty air filter and clean or replace.
		X
			Reduced or no air flow in cooling	Check fan motor operation and airflow restrictions.
				Too high of external static. Check static vs. blower table.
Insufficient capacity/ Not
	X	X	Leaky duct work	Check supply and return air temperatures at the unit and at distant duct registers
cooling or heating				if significantly different, duct leaks are present.
	X	X	Low refrigerant charge	Check superheat and subcooling per chart.
	X	X	Restricted metering device	Check superheat and subcooling per chart. Replace.
		X	Defective reversing valve	Perform RV touch test.
	X	X	Thermostat improperly located	Check location and for air drafts behind stat.
	X	X	Unit undersized	Recheck loads & sizing. Check sensible clg. load and heat pump capacity.
	X	X	Scaling in water heat exchanger	Perform scaling check and clean if necessary.
	X	X	Inlet water too hot or too cold	Check load, loop sizing, loop backfill, ground moisture.
				Check for dirty air filter and clean or replace.
	X		Reduced or no air flow in heating
				Check fan motor operation and air flow restrictions.
				Too high of external static. Check static vs. blower table.
		X	Reduced or no water flow in cooling	Check pump operation or valve operation/setting.
				Check water flow. Adjust to proper flow rate.
High Head Pressure
		X	Inlet water too hot	Check load, loop sizing, loop backfill, ground moisture.
	X		Air temperature out of range in heating	Bring return air temperature within design parameters.
		X	Scaling in water heat exchanger	Perform scaling check and clean if necessary.
	X	X	Unit overcharged	Check superheat and subcooling. Re-weigh in charge.
	X	X	Non-condensables in system	Vacuum system and re-weigh in charge.
	X	X	Restricted metering device.	Check superheat and subcooling per chart. Replace.
				Check pump operation or water valve operation/setting.
	X		Reduced water flow in heating.
				Plugged strainer or filter. Clean or replace.
				Check water flow. Adjust to proper flow rate.
	X		Water temperature out of range.	Bring water temperature within design parameters.
Low Suction Pressure				Check for dirty air filter and clean or replace.
		X	Reduced air flow in cooling.	Check fan motor operation and air flow 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 temperature within design parameters.
	X	X	Insufficient charge	Check for refrigerant leaks.
Low Discharge Air Temperature	X		Too high of air flow	Check fan motor speed selection and air flow chart.
in Heating	X		Poor performance	See ‘Insufficient Capacity’
High humidity		X	Too high of air flow	Check fan motor speed selection and airflow chart.
		X	Unit oversized	Recheck loads & sizing. Check sensible clg load and heat pump capacity.

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