Installation manual

Functional Troubleshooting
Performance Troubleshooting
Performance Troubleshooting Htg Clg Possible Cause Solution
Insuf¿ cient capacity/ Not
cooling or heating
XXDirty ¿ lter Replace or clean.
X Reduced or no air À ow in heating
Check for dirty air ¿ lter and clean or replace.
Check fan motor operation and airÀ ow restrictions.
Too high of external static. Check static vs. blower table.
X Reduced or no air À ow in cooling
Check for dirty air ¿ lter and clean or replace.
Check fan motor operation and airÀ ow restrictions.
Too high of external static. Check static vs. blower table.
XXLeaky duct work
Check supply and return air temperatures at the unit and at distant duct registers
if signi¿ cantly different, duct leaks are present.
XXLow refrigerant charge Check superheat and subcooling per chart.
XXRestricted metering device Check superheat and subcooling per chart. Replace.
X Defective reversing valve Perform RV touch test.
XXThermostat improperly located Check location and for air drafts behind stat.
XXUnit undersized Recheck loads & sizing. Check sensible clg. load and heat pump capacity.
XXScaling in water heat exchanger Perform scaling check and clean if necessary.
XXInlet water too hot or too cold Check load, loop sizing, loop back¿ ll, ground moisture.
High Head Pressure
X Reduced or no air À ow in heating
Check for dirty air ¿ lter and clean or replace.
Check fan motor operation and air À ow restrictions.
Too high of external static. Check static vs. blower table.
X Reduced or no water À ow in cooling
Check pump operation or valve operation/setting.
Check water À ow. Adjust to proper À ow rate.
X Inlet water too hot Check load, loop sizing, loop back¿ ll, 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.
XXUnit overcharged Check superheat and subcooling. Re-weigh in charge.
XXNon-condensables in system Vacuum system and re-weigh in charge.
XXRestricted metering device. Check superheat and subcooling per chart. Replace.
Low Suction Pressure
X Reduced water À ow in heating.
Check pump operation or water valve operation/setting.
Plugged strainer or ¿ lter. Clean or replace.
Check water À ow. Adjust to proper À ow rate.
X Water temperature out of range. Bring water temperature within design parameters.
X Reduced air À ow in cooling.
Check for dirty air ¿ lter and clean or replace.
Check fan motor operation and air À ow 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.
XXInsuf¿ cient charge Check for refrigerant leaks.
Low Discharge Air Temperature
in Heating
X Too high of air À ow Check fan motor speed selection and air À ow chart.
X
Poor performance See ‘Insuf¿ cient Capacity’
High humidity
X Too high of air À ow Check fan motor speed selection and airÀ ow chart.
X Unit oversized Recheck loads & sizing. Check sensible clg load and heat pump capacity.
Only Compressor Runs
XXThermostat wiring Check G wiring at heat pump. Jumper G and R for fan operation
XX
Fan motor relay
Jumper G and R for fan operation. Check for Line voltage across BR contacts.
XX Check fan power enable relay operation (if present).
XXFan motor Check for line voltage at motor. Check capacitor.
XXThermostat wiring
Check thermostat wiring at heat pump. Jumper Y and R for compressor operation
in test mode
Unit Doesn’t Operate
in Cooling
X Reversing valve
Set for cooling demand and check 24VAC on RV coil and at CXM/DXM board.
If RV is stuck, run high pressure up by reducing water À ow and while operating
engage and disengage RV coil voltage to push valve.
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’.
X Thermostat wiring
Put thermostat in cooling mode. Check 24 VAC on O (check between C and
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.
Residential Split Units - 60Hz Puron
®
Rev.: 6 Dec., 2011
50