Rheem Heat Pump Troubleshooting | Heat Pump troubleshooting

The tables below contain the lists of possible breakdowns which may happen with Rheem heat pumps of different modifications. In case of Rheem heat pump not working you should address these checklists.

There are types of faults and problems with detailed descriptions, possible causes and solutions which may be recommended in the certain situations. If you feel the temperature in your house is getting higher, it may be because of heat pump fan not spinning, and therefore, heat pump not cooling. The information given below can be helpful for you then.

Rheem R-410A Heat Pump Troubleshooting

SYMPTOM	POSSIBLE CAUSE	REMEDY
Unit will not run	• Power off or loose electrical connection	• Check for correct voltage at line voltage connections in condensing unit.
	• Thermostat out of calibration - set too high	• Reset.
	• Defective control board	• Check control board diagnostic codes.
	• Blown fuses/tripped breaker	• Replace fuses/reset breaker.
	• Transformer defective	• Check wiring. Replace transformer.
	• High-pressure control open	• Reset. Also see high head pressure remedy. The high- pressure control opens at 610 PSIG.
	• Miswiring of communications (communication light on continuously)	• Check communication wiring.
Outdoor fan runs, compressor doesn't	• Run or start capacitor defective	• Replace.
	• Start relay defective	• Replace.
	• Loose connection	• Check for correct voltage at compressor. Check and tighten all connections.
	• Compressor stuck, grounded or open motor winding, open internal overload.	• Wait at least 3 hours for overload to reset. If still open, replace the compressor.
	• Low-voltage condition	• Add start kit components.
Insufficient cooling	• Improperly sized unit	• Recalculate load.
	• Improper indoor airflow	• Check. Should be approximately 400 CFM per ton.
	• Incorrect refrigerant charge	• Charge per procedure attached to unit service panel.
	• Air, noncondensibles, or moisture in system	• Recover refrigerant. Evacuate and recharge. Add filter drier.
Compressor short cycles	• Incorrect voltage	• At compressor terminals, voltage must be ± 10% of nameplate marking when unit is operating.
	• Defective overload protector	• Replace. Check for correct voltage.
	• Refrigerant undercharge	• Add refrigerant.
Registers sweat	• Low indoor airflow	• Increase speed of blower or reduce restriction. Replace air filter.
High head, low vapor pressures	• Restriction in liquid line, expansion device, or filter drier	• Remove or replace defective component.
	• Bad TXV	• Replace TXV.
High head, high or normal vapor pressure - Cooling mode	• Dirty outdoor coil	• Clean coil.
	• Refrigerant overcharge	• Correct system charge.
	• Outdoor fan not running	• Repair or replace.
	• Air or noncondensibles in system	• Recover refrigerant. Evacuate and recharge.
Low head, high vapor pressures	• Bad TXV	• Replace TXV.
	• Bad compressor	• Replace compressor.
Low vapor, cool compressor, iced indoor coil	• Low indoor airflow	• Increase speed of blower or reduce restriction. Replace air filter.
	• Operating below 65°F outdoors	• Add Low Ambient Kit.
	• Moisture in system	• Recover refrigerant. Evacuate and recharge. Add filter drier.
High vapor pressure	• Excessive load	• Recheck load calculation.
	• Defective compressor	• Replace.
Fluctuating head and vapor pressures	• TXV hunting	• Check TXV bulb clamp. Check air distribution on coil. Replace TXV.
	• Air or noncondensibles in system	• Recover refrigerant. Evacuate and recharge.
Gurgle or pulsing noise at expansion device or liquid line	• Air or noncondensibles in system	• Recover refrigerant. Evacuate and recharge.

Rheem RP13 Heat Pump Troubleshooting

SYMPTOM	POSSIBLE CAUSE	CHECK OR REMEDIES
Voltage present on compressor contactor and compressor won't run	Compressor start components	Check start capacitor.
		Check potential relay.
	Run capacitor	Check with ohmmeter
	Internal overload	Allow time to reset.
	Compressor windings	Check for correct ohms.
Voltage present on line side of compressor contactor only	Thermostat	Check for control voltage to contactor coil.
	Compressor control circuit	High-pressure switch
		Low-pressure switch
		Ambient thermostat
		Solid-state protection control or internal thermal sensors
		Compressor timed off/on control or interlock
No voltage on line side of compressor contactor	Blown fuses or tripped circuit breaker	Check for short in wiring or unit.
	Improper wiring	Recheck wiring diagram.
Improper voltage	High voltage	Wrong unit
		Power supply problem
	Low voltage	Wrong unit
		Power supply problem
		Wiring undersized
		Loose connections
	Single Phasing (3 phase)	Check incoming power and fusing.
Liquid in the compressor shell	Faulty or missing crankcase heater	Replace crankcase heater.
Too much liquid in system	Incorrect piping	Check piping guidelines.
	Overcharge	Check and adjust charge.
Moisture	Poor evacuation on installation or during service	In each case, the cure is the same. Recover refrigerant. Add filter drier, evacuate, and recharge.
High head pressure	Noncondensibles air
Unusual head and suction readings	Wrong refrigerant or mixed refrigerants
Foreign matter - copper filings	Copper tubing cuttings
Copper oxide	Dirty copper piping or nitrogen not used when brazing
Welding scale	Nitrogen not used during brazing
Soldering flux	Adding flux before seating copper partway
Excess soft solder	Wrong solder material
Compressor failures	Line tubing too large	Reduce pipe size to improve oil return.
Low suction pressure	Low charge	Check system charge.
	Refrigerant leaks	Repair and recharge.
Cold, noisy compressor - Slugging	Dilution of oil with refrigerant	Observe piping guidelines.
Noisy compressor	Migration	Check crankcase heater.
Cold, sweating compressor	Flooding	Check system charge.
Low load	Reduced airflow	Dirty filter
		Dirty coil
		Wrong duct size
		Restricted duct
	Thermostat setting	Advise customer.
Short cycling of compressor	Faulty high- or low-pressure control	Replace control.
	Loose wiring	Check all control wires.
	Thermostat	In supply air stream, out of calibration
		Customer misuse
On start-up	Incorrect piping	Review pipe size guidelines.
TEV hunting when running	Faulty TEV	Replace TEV.

Rheem MPi Series Heat Pump Troubleshooting

Flashes	Fault Modes	Solution
1 x red	Heating unit on (possible circulator fault)	compressor over temperature
2 x red	Heating unit off	compressor fault condition
3 x red		compressor cooling fault condition
4 x red		tank thermistor fault condition
5 x red		evaporator thermistor fault condition
6 x red		compressor thermistor fault condition
9 x red		compressor fault condition

Rheem RRPL-B Series Heat Pump Troubleshooting

LED 1	LED 2	Control Board Status
OFF	OFF	No Power
ON	ON	Coil Sensor Failure
OFF	ON	Ambient Sensor Failure
FLASH	FLASH	Normal
OFF	FLASH	Low Pressure Lockout (short test Dins to reset)
FLASH	OFF	High Pressure Lockout (short test Dins to reset)
ON	FLASH	Low Pressure Control Open
FLASH	ON	High Pressure Control Open
Alternate Flashing		5 Minute Time Delay

Rheem RP15 Heat Pump Troubleshooting

SYMPTOMS	POSSIBLE CAUSE	CHECK OR REMEDIES
Compressor failures	Line tubing too long	Add oil to the recommended level
	Line tubing too large	Reduce pipe size to improve oil return
Low suction pressure	Low charge	Check system charge
	Refrigerant leaks	Repair and recharge
Cold, Noisy compressor - Slugging	Dilution of Oil with Refrigerant	Observe piping guidelines
Noisy compressor	Migration	Check crankcase heater
Cold, sweating compressor	Flooding	Check system charge
Low Load	Reduced air flow	Dirty filter
		Dirty coil
		Wrong duct size
		Restricted duct
	Thermostat setting	Advise customer
Short cyding of compressor	Faulty pressure control	Replace control
	Loose wiring	Check all control wires
	Thermostat	In supply air stream, out of calibration,
		Customer misuse
Liquid in the compressor shell	Faulty or missing crankcase heater	Replace crankcase heater
Too much liquid in system	Incorrect piping	Check Piping guidelines
	Overcharge	Check and adjust charge
On start up	Incorrect piping	Review pipe size guidelines
TEV hunting when running	Oversized TEV	Check TEV application
Poor system control using a TEV	Loose sensing bulb	Secure the bulb and insulate
	Bulb in wrong location	Relocate bulb
	Wrong size TEV	Use correct replacement
	Improper superheat setting	Adjust, if possible; Replace, if not
Poor system control using capillary tubes	Overcharge	Check system charge
	High head pressures	Dirty heat pump
		Restricted air flow
		Recirculation of air
	Evaporator air flow too low	Adjust air flow to 400 CFM [188.8 L/s]/Ton
High Superheat, Low Suction Pressure	Moisture freezing and blocking valve	Recover charge, install filter-drier, evacuate system, recharge
	Dirt or foreign material blocking valve	Recover charge, install filter-drier, evacuate system, recharge
	Low refrigerant charge	Correct the charge
	Vapor bubbles in liquid line	Remove restriction in liquid line Correct the refrigerant charge
		Remove non-condensable gases
		Size liquid line correctly
	Misapplication of internally equalized valve	Use correct TEV
	Plugged external equalizer line	Remove external equalizer line restriction
	Undersized TEV	Replace with correct valve
	Loss of charge from power head sensing bulb	Replace power head or complete TEV
	Charge migration from sensing bulb to power head (Warm power head with warm, wet cloth. Does valve operate correctly now?)	Ensure TEV is warmer than sensing bulb
	Improper superheat adjustment (Only applicable to TEV with adjustable superheat settings)	Adjust superheat setting counter- clockwise
Valve feeds too much refrigerant, with low superheat and higher than mat suction pressure	Moisture causing valve to stick open.	Recover refrigerant, replace filter- drier, evacuate system and then nor- recharge
	Dirt or foreign material causing valve to stick open	Recover refrigerant, replace filter- drier, evacuate system and recharge
	TEV seat leak (A gurgling or hissing sound is heard AT THE TEV during the off cycle, if this is the cause.) NOT APPLICABLE TO BLEED PORT VALVES.	Replace the TEV
	Oversized TEV	Install correct TEV
	Incorrect sensing bulb location	Install bulb with two mounting straps, in 2:00 or 4:00 position on suction line, with insulation
	Low superheat adjustment (only applicable to TEV with adjustable superheat setting)	Turn superheat adjustment clockwise
	Incorrectly installed, or restricted external equalizer line	Remove restriction, or relocate external equalizer

Rheem PPL-JAZ Series Heat Pump Troubleshooting

FAULT	DESCRIPTION	SOLUTION
Motor rocks slightly when starting	No movement	This is normal start-up for ECM.
Motor will not start	No movement	Check power at motor.
		Check low voltage (24-vac R to C) at motor.
		Check low voltage connections (G.Y W. R. C) at motor.
		Check for unseated Dins in connectors on motor harness.
		Check motor for tight shaft.
		Perform motor/control replacement check.
		Run moisture check.
	Motor rocks	Check for loose or non-compliant motor mount.
		Make sure blower wheel is tight on shaft.
		Perform motor/control replacement check.
Motor oscillates up and down while being tested off of blower		It is normal for motor to oscillate with no load on shaft.
Motor starts, but runs erratically	Varies up and down or intermittent	Check line voltage for variation or “saq."
		Check law voltage connections (G,Y W, R ; C) at motor, unseated pins in motor harness connectors.
		Check “Bk” for erratic cfm command (in variable speed applications).
		Check system controls, thermostat.
		Perform moisture check.
	“Hunts" or “puffs” at high cfm (SDeed)	If removing panel or filter reduces “puffing,” reduce restriction or reduce maximum airflow.
	Stays at low cfm despite system call for cool or heat cfm	Check lew voltage (thermostat) wires and connections.
		Verity fan is not in delay mode. Wait until delay is complete.
		Perform motor/control replacement check.
	Stays at high cfm	Check to see if “R” is missing/not connected at motor
		Verify fan is not in delay mode. Wait until delay is complete.
		Perform motor/control replacement check.
	Blower will not shut off	Check to see if there is current leakage from controls into G, Y, or W. Check for Triac switched thermostat or solid state relay.
Excessive noise	Noisy blower or cabinet	determine if it’s air. cabinet, duct, or motor noise.
		Check for loose blower housing. panels. etc.
		If high static is creating high blower speed, check for air whistling through seams in ducts, cabinets, or panels.
		If high static is creating high blower speed. check for cabinet/duct deformation.
	“Hunts" or “puffs” at high cfm (speed)	If removing panel or filter reduces '‘puffing; reduce restriction or reduce maximum airflow.
Evidence of moisture	Motor failure or malfunction has occurred and moisture is present	Replace motor and perform moisture check..
	Evidence of moisture present inside air mover	Perform moisture check.

Rheem RRP Series Heat Pump Troubleshooting

Dual 7-Segment LEDs Display Code	Status/Possible Cause - Troubleshooting Information
L 8	-Check model data card is properly connected.
	-Cycle power - remove power until all the lights on the inverter have gone out. Then restore power to inverter then ICC.
	-Replace model data card
L15	-Verify high voltage connections at the terminal block, filter and inverter are all tight.
	- Verify communication cable connection between the inverter and ICC is complete. -Check the U/V/W output wires are correct.
	- Verify there is not a short in the filter or choke.
	- Verify input voltage is within 187VAC and 252VAC.
	-Check outdoor airflow and verify OD fan is operating.
	-Check the power inverter heat sync for debris.
	-Check model data card for defects -Replace model data card -Check charge level. Reduce charge.
	-If none of the above corrects the issue, replace drive.
L16	-Power cycle the system. Verify all lights on the inverter are out prior to returning power to the drive.
	-Check the U/V/W output wires are correct.
	-Check charge level. Reduce charge.
	- Check continuity of discharge line thermistor and connection at the drive. If issue persists, replace the thermistor.
	-If none of the above corrects the issue, replace drive.
L17	-Outdoor ambient is above 125 # F. Allow unit to cool and condensing pressure to reduce before restarting.
	-Outdoor ambient is below 0 # F. Allow unit to heat up and evaporating pressure to increase before restarting.
	- Check charge level. Reduce charge.
L18	- Verify communication cable connection between the inverter and ICC is complete.
	- Verify shielding on communication cable is adequately connected to the connector.
	- Verify crimp terminals in the ICC to inverter communication cable are fully inserted and making good contact with the receptacle.
31	-Check charge level. Reduce charge. -Charge migration could have occurred resulting in high compression ratio.
	-If ambient above 110*F or below 0 # F compression ratio could be too high for low speed operation.
	-ICC will clear this fault and restart independently.
L31	-Check charge level. Reduce charge. -Outdoor ambient is above 125 # F. Allow unit to cool and condensing pressure to reduce before restarting.
	- Outdoor ambient is below 0*F. Allow unit to heat up and evaporating pressure increase before restarting.
	-Cycle power to restart.
L32	- Check Thermistor continuity. The compressor thermistor is a 10k thermistor.
L33	- Check Thermistor continuity. The Evaporator thermistor is a 10k thermistor.
L36	-Check pressure transducer wiring harness for continuity while attached to sensor.
	- Check 5Vdc is constant between black and red at the sensor.
	-Check return voltage between Black and Green terminals on back of control board.
	-Calculate the gauge pressure from the voltage readings: PSIG = (375 *
	-On a legacy controlled system verify that the voltage readings convert to the

Rheem RJNA Series Heat Pump Troubleshooting

Discharge Pressure	Suction Pressure	Sub-cooling	Compressor Amps	System Problem
High	Low/ Normal	High	High	Overcharge
Low	Low	Low	Low	Undercharge
Low	Low	High	Low	Liquid Line Restriction
High	Low	Low	Low	Low Evaporator Airflow
High	High/ Normal	Low	High	Dirty outdoor Coil
Low	Low	High	Low	Low Outside Ambient temperature
Low	Low	High	Low	TXV sensing bulb charge lost
High	High	Low	High	Poorly Insulated Sensing Bulb