Intertherm Heat Pump Troubleshooting

Interherm heat pumps function very well in most cases. However, it doesn’t mean you should throw it away if the problem occurs. There is also a way out and in this case it is connected with the troubleshooting guide given here. It’s going to be a great help in any difficult situation. Just find the issue you faced and start the repair.

Intertherm HSA1BE Heat Pump Troubleshooting

Error Code on indoor unitMalfunctionRepair Method/Cause
EEIndoor PCB MalfunctionReplace indoor main board
E2Anti-freeze ProtectionOutdoor ambient temperature is too low
H4System overload protectionCheck for dirty or blocked heat exchangers
H6Indoor motor malfunctionCheck motor mounting and wiring
F2Indoor pipe temperature sensor malfunctionMeasure the resistance value in the sensor
F1Return air temperature sensor malfunction
UFIndoor board malfunctionReplace indoor main board
H3Compressor overload protectionCheck overload wiring
LcCompressor start-up failureCheck if the resistance of the compressor and the resistance to ground is normal. If the resistance is normal, the outdoor main board may be defective.
UHOutdoor fan motor failureCheck outdoor motor
E5Low voltage protectionCheck incoming power
U74-way valve malfunctionReplace 4-way valve
U1Compressor phase detection errorReplace outdoor main board
H7Compressor speed reductionCheck if the resistance of the compressor and the resistance to ground is normal. If the resistance is normal, the outdoor main board may be defective.
U5Current detection malfunctionReplace outdoor main board
F3Outdoor ambient temperature sensor malfunctionMeasure the resistance value in the sensor
E4Discharge temperature sensor malfunction (out of range)
F5Discharge temperature sensor malfunction (open or shorted)
F4Condenser temperature sensor malfunction (open or shorted)
P8Heat sink over-temperatureIs outdoor ambient temperature out of system operating range? Is heat sink blocked or damaged?
UUDC over-current
P7Heat sink temperature sensor malfunctionReplace outdoor main board
FOLow chargeCheck for leaks
PHDC input voltage is too highCheck incoming power supply
PLDC input voltage is too low
E6Communication malfunctionCheck wiring connection
UAIndoor and outdoor unit mismatchedCheck system combination

Intertherm HSA1QE Heat Pump Troubleshooting

Green Led (DS2)Red Led (DS1)Mode
OFFOFFNo power to control
Simultaneous Slow FlashSimultaneous Slow FlashNormal operation/ power to control
Alternating Slow FlashAlternating Slow FlashAnti-short cycle lockout
OFFSlow FLASHLow pressure switch fault (Optional)
OFFONLow pressure switch lockout (Optional)
Slow FLASHOFFHigh presssure switch fault (Optional)
OFFOFFHigh pressure switch lockout (Optional)

Intertherm HSH1BE Heat Pump Troubleshooting

Miswired Module IndicationRecommended Troubleshooting Action
Green LED is not on, module does not power upDetermine if both R and C module terminals are connected. Verify voltage is present at module’s R and C terminals. Review 24VAC Power Wiring for R and C wiring.
Green LED intermittent, module powers up only when compressor runsDetermine if R and Y terminals are wired in reverse. Verify module’s R and C terminals have a constant source. Review 24VAC Power Wiring for R and C wiring.
TRIP LED is on but system and compressor check OKVerify Y terminal is connected to 24VAC at contactor coil. Verify voltage at contactor coil falls below 0.5VAC when off. Verify 24 VAC is present across Y and C when thermostat demand signal is present. If not, R and C are reverse wired.
TRIP LED and ALERT LED flashing togetherVerify R and C terminals are supplied with 19-28VAC.
ALERT Flash Code 3 (Compressor Short Cycling) displayed incorrectlyVerify Y terminal is connected to 24VAC at contactor coil. Verify voltage at contactor coil falls below 0.5VAC when off.
ALERT Flash Code 5, 6 or 7 (Open Circuit, Open Start Circuit or Open Run Circuit) displayed incorrectlyCheck that compressor run and start wires are through module’s current sensing holes. Verify Y terminal is connected to 24VAC at contactor coil. Verify voltage at contactor coil falls below 0.5VAC when off.
ALERT Flash Code 8 (Welded Contactor) displayed incorrectlyDetermine if module’s Y terminal is connected. Verify Y terminal is connected to 24VAC at contactor coil. Verify 24VAC is present across Y and C when thermostat demand signal is present. If not, R and C are reverse wired. Verify voltage at contactor coil falls below 0.5VAC when off. Review Thermostat Demand Wiring (page 4) for Y and C wiring.

Intertherm HSH1QE Heat Pump Troubleshooting

Status LEDStatus LED DescriptionStatus LED Troubleshooting Information
Green "POWER”Module has powerSupply voltage is present at module terminals
Red "TRIP”Thermostat demand signal Y is present, but the compressor is not running1. Compressor protector is open
2. Outdoor unit power disconnect is open
3. Compressor circuit breaker or fuse(s) is open
4. Broken wire or connector is not making contact
5. Low pressure switch open if present in system & Compressor contactor has failed open
Yellow “ALERT" Flash Code 1Long Run Time Compressor is running extremely long run cycles1. Low refrigerant charge
2. Evaporator blower is not running
3. Evaporator coil is frozen
4. Faulty metering device
5. Condenser coil is dirty & Liquid line restriction (filter drier blocked if present in system)
7. Thermostat is malfunctioning
8. Comfort Alert Failure
Yellow “ALERT” Flash Code 2System Pressure Trip Discharge or suction pressure out of limits or compressor overloaded1. High head pressure
2. Condenser coil poor air circulation (dirty, blocked, damaged)
3. Condenser fan is not running
4. Return air duct has substantial leakage
5. If low pressure switch present in system, check Flash Codel information
Yellow “ALERT" Flash Code 3Short Cycling Compressor is running only briefly1. Thermostat demand signal is intermittent
2. Time delay relay or control board defective
3. If high pressure switch present go to Rash Code 2 information
4. If low pressure switch present go to Flash Code 1 information
Yellow “ALERT" Flash Code 4Locked Rotor1. Run capacitor has failed
2. Low line voltage (contact utility if voltage at disconnect is low)
• Check wiring connections
1 Excessive liquid refrigerant in compressor 4. Compressor bearings are seized
• Measure compressor oil level
Yellow “ALERT” Flash Code 5Open Circuit1. Outdoor unit power disconnect is open
2. Com pressor circuit breaker or f use(s) is open
3. Compressor contactor has failed open
• Check compressor contactor wiring and connectors
• Check for compressor contactor failure (burned, pitted or open)
• Check wiring and connectors between supply and compressor
• Check for low pilot voltage at compressor contactor coil
4. High pressure switch is open and requires manual reset
5. Open circuit in compressor supply wiring or connections & Unusually long compressor protector reset time due to extreme ambient temperature
6. Compressor windings are damaged
• Check compressor motor winding resistance
Yellow “ ALERT " Flash Code 6Open Start Circuit Current only in run circuit1. Run capacitor has failed
2. Open circuit in compressor start wiring or connections
• Check wiring and connectors between supply and the compressor “S” terminal
1 Compressor start winding is damaged
• Check compressor motor winding resistance
Yellow "ALERT” Flash Code 7Open Run Circuit Current only in start circuit1. Open circuit in compressor run wiring or connections
• Check wiring and connectors between supply and the compressor “R" terminal
2. Compressor run winding is damaged
• Check compressor motor winding resistance
Yellow “ ALERT " Flash Code 8Welded Contactor Compressor always runs1. Compressor contactor has failed closed
2. Thermostat demand signal not connected to module
Yellow "ALERT" Flash Code 9Low Voltage Control circuit« 17VAC1. Control circuit transformer is overloaded
2. Low line voltage (contact utility if voltage at disconnect is low)
• Check wiring connections