Updated July 30, 2026: Heat pump controls and outdoor-unit behaviour vary by equipment type, thermostat, backup-heating configuration and manufacturer. An outdoor fan that is temporarily stopped does not necessarily mean the complete outdoor unit has failed, particularly during normal defrost operation.
If your heat pump outdoor unit is not running, first determine whether the system is actually requesting compressor operation. The outdoor unit may be intentionally off because the thermostat is satisfied, Emergency Heat or furnace backup is active, a control delay is in progress or the system is in a normal operating sequence. It can also be off because of an electrical, control, inverter, fan, compressor, sensor or refrigeration-system fault.
Do not diagnose the compressor simply because the outdoor fan is stopped. During normal winter defrost, for example, the outdoor fan commonly stops temporarily while the refrigeration system continues operating.
Repeated breaker trips, burning smells, smoke, severe mechanical noise or visibly damaged electrical equipment are different. Stop using the system and arrange professional service rather than repeatedly resetting protection or opening the outdoor cabinet.
Why Is My Heat Pump Outdoor Unit Not Running?
The cause can be completely normal or require professional repair.
Possible Normal Reasons
- The thermostat has reached the setpoint.
- The compressor is in a normal restart delay.
- The system is temporarily changing operation during defrost.
- A dual-fuel system has intentionally switched to the furnace.
- Emergency Heat has placed a central system in backup-only operation.
Possible Faults
- No outdoor electrical power
- Tripped breaker or protection
- Contactor or relay fault
- Control-board problem
- Inverter fault
- Compressor fault
- Outdoor fan fault
- Sensor or safety lockout
- Communication problem
- Refrigeration-system problem
First Determine What Is Actually Not Running
There is an important difference between:
- The outdoor fan not turning
- The compressor not operating
- The entire outdoor unit having no power
From outside the cabinet, a homeowner cannot always distinguish those conditions safely.
Can a Heat Pump Outdoor Unit Being Off Be Normal?
Yes.
Thermostat Satisfied
When the indoor temperature reaches the target, the system may reduce output or stop according to its control strategy.
Variable-Speed Heat Pumps
Modern equipment may operate at very low output and can sound dramatically quieter than older single-speed systems.
Defrost
Natural Resources Canada explains that frost can accumulate on the outdoor coil during winter heating. During a common defrost sequence, the refrigeration cycle changes temporarily and the outdoor fan is shut off while heat is directed toward the outdoor coil.
Dual Fuel
A properly configured heat pump and furnace system may intentionally use the furnace instead of the outdoor heat pump under selected conditions.
Emergency Heat
On many central systems, selecting Emergency Heat locks out normal compressor heating and relies on the configured backup source.
Therefore, do not schedule a compressor funeral based entirely on ten seconds of looking through the window.
1. The Thermostat Is Already Satisfied
Start with the simplest explanation.
Check:
- Current indoor temperature
- Heating or cooling setpoint
- Heat or Cool mode
- Schedule
If the room is already at setpoint, the outdoor unit may not need to operate.
Cooling Example
If the thermostat is set to 23°C and the room is already at 23°C, an outdoor unit that is off may be doing exactly what it was asked to do.
Heating Example
The same applies in Heat mode when the heating demand has been satisfied.
2. Emergency Heat or Backup Heating Is Active
A central heat pump can sometimes heat the home while the outdoor unit remains off.
Emergency Heat
On many systems, Emergency Heat disables normal heat-pump compressor heating and relies on backup heat.
Backup Could Be:
- Electric resistance heat
- Gas furnace
- Another configured heating source
Check the Thermostat Display
Look for terms such as:
- Emergency Heat
- EM Heat
- Backup Heat
- AUX
AUX and Emergency Heat Are Different
In an all-electric system, AUX Heat may operate while the outdoor heat pump continues running.
Emergency Heat commonly represents backup-only operation.
3. The Heat Pump Is in Defrost
Winter defrost is one of the most common sources of homeowner confusion.
Why Defrost Happens
During heating, the outdoor coil becomes cold enough for moisture in outdoor air to freeze on it.
That frost eventually needs to be removed.
During a Common Defrost Cycle:
- The reversing valve changes refrigeration operation temporarily.
- Hot refrigerant is directed toward the outdoor coil.
- The outdoor fan typically stops.
- Frost melts into water.
- Visible vapour may appear.
The Outdoor Fan Stopping Is Intentional
Natural Resources Canada explains that shutting the outdoor fan off during defrost reduces the heat required to melt frost from the coil.
Defrost Should Be Temporary
Arrange service when:
- The outdoor coil remains heavily iced.
- The system repeatedly enters abnormal defrost behaviour.
- Heating does not resume afterward.
- The home cannot maintain temperature.
4. A Normal Control Delay Is Active
Heat pumps commonly use protective timing logic to avoid rapid compressor restarting.
This Can Happen After:
- Changing the thermostat mode
- Changing the setpoint
- A brief power interruption
- The compressor shutting off
Do Not Repeatedly Cycle Power
Constantly switching breakers, thermostats and disconnects can interfere with diagnosis and may simply restart the delay.
Give the Controls Time to Respond
Follow the manufacturer or thermostat instructions for the specific system.
5. The Outdoor Unit Has Lost Electrical Power
The indoor equipment and outdoor equipment may have separate electrical supplies.
This Means the Indoor Fan Can Run While the Outdoor Heat Pump Does Not
Possible causes include:
- Branch-circuit problem
- Outdoor disconnect problem
- Loose or damaged electrical connection
- Internal electrical fault
Homeowner Check
You can visually check the electrical panel for an obvious tripped breaker.
Do Not:
- Open the outdoor disconnect
- Remove electrical covers
- Measure live voltage
- Touch damaged wiring
Electrical heat pump work requires appropriate qualifications and safety procedures.
6. The Breaker or Electrical Protection Has Tripped
A tripped breaker can explain why the indoor system appears active while the outdoor unit is dead.
Possible Causes Include:
- Compressor electrical fault
- Inverter fault
- Outdoor fan motor fault
- Damaged wiring
- Electrical connection problem
- Other internal equipment fault
Do Not Repeatedly Reset It
If protection trips again, stop operating the heat pump and arrange service.
Never Replace It With a Larger Breaker
A larger overcurrent device can remove electrical protection without correcting the problem that caused the trip.
7. A Contactor, Relay or Switching Component Has Failed
Traditional heat pump systems can use electrical switching devices to energize compressor and fan circuits.
A Failed Switching Component Can Cause:
- No compressor operation
- No outdoor fan operation
- Intermittent starting
- Electrical buzzing
Not Every System Uses the Same Architecture
Modern inverter equipment can use electronic power control rather than the conventional arrangements found in older single-speed systems.
Diagnosis Requires Electrical Testing
Do not open the outdoor cabinet or attempt to push, jumper or bypass electrical components.
8. The Outdoor Control Board Has a Fault
Modern outdoor units rely on electronic controls to coordinate:
- Compressor operation
- Outdoor fan
- Defrost
- Sensors
- Communication
- Protection
A Control Problem Can Make the Complete Outdoor Unit Appear Dead
But a control-board fault should be confirmed before replacing the board.
Similar Symptoms Can Come From:
- No supply power
- Communication failure
- Sensor problem
- Inverter fault
- Damaged wiring
A Fault Code Helps, but It Is Not Always a Parts List
Error codes identify conditions requiring investigation. They do not necessarily prove which physical component must be replaced.
9. The Inverter or Compressor Drive Has a Problem
Many variable-capacity heat pumps use inverter electronics to control compressor speed.
If the Inverter Cannot Operate Correctly:
The compressor may remain stopped even if the compressor itself is not mechanically failed.
Possible Related Issues Include:
- Power-module fault
- Control-board fault
- Communication fault
- Compressor electrical problem
- Supply-power issue
This Is Why Modern Heat Pumps Need System-Level Diagnosis
Old single-speed compressor assumptions should not be applied blindly to inverter equipment.
10. The Compressor Cannot Operate Normally
A failed compressor can prevent normal heating and cooling.
Possible Compressor Problems Include:
- Electrical failure
- Internal mechanical failure
- Protection lockout
- Abnormal operating condition
But Confirm the Diagnosis
Several other faults can prevent the compressor from operating even when the compressor itself is still functional.
Before Replacing a Compressor, Ask:
- How was failure confirmed?
- What likely caused it?
- Is warranty coverage available?
- What is the condition of the rest of the system?
11. The Outdoor Fan Has Failed
The outdoor fan moves air across the outdoor coil.
A Fan Problem Can Result From:
- Fan motor failure
- Control problem
- Electrical fault
- Physical obstruction
- Fan blade damage
Remember Defrost
A stationary outdoor fan during winter defrost can be completely normal.
A Fan That Remains Off During Normal Operation Is Different
If the compressor appears to operate but the fan remains stopped outside an expected operating sequence, shut the system down and arrange diagnosis.
Operating without required outdoor airflow can create abnormal refrigeration conditions.
12. A Sensor or Safety Control Has Stopped Operation
Heat pumps monitor several conditions to protect the equipment.
Depending on the System, Controls Can Monitor:
- Outdoor temperature
- Coil temperature
- Refrigerant conditions
- Compressor temperature
- Electrical conditions
A Bad Sensor Can Cause Incorrect Protection Behaviour
The heat pump may stop because the controls believe an unsafe or abnormal condition exists.
A Safety Shutdown Should Not Simply Be Bypassed
Determine whether:
- The monitored condition is genuinely abnormal
- The sensor or circuit is faulty
13. The Indoor and Outdoor Units Are Not Communicating
Many modern systems depend on electronic communication between indoor and outdoor equipment.
A Communication Fault Can Cause:
- Outdoor unit not starting
- Fault codes
- Intermittent operation
- One or more zones becoming unavailable
Possible Causes Include:
- Wiring fault
- Loose connection
- Incorrect wiring
- Indoor control problem
- Outdoor control problem
- Power-supply issue
Recent Work Can Be Relevant
If the problem began immediately after:
- Thermostat replacement
- Electrical work
- Equipment service
tell the technician.
14. Refrigerant Conditions Have Triggered Protection
A heat pump may shut down when refrigeration operating conditions move outside its permitted range.
Possible Causes Can Include:
- Refrigerant leak
- Incorrect refrigerant charge
- Restriction
- Indoor airflow problem
- Outdoor airflow problem
- Fan failure
Do Not Add Refrigerant Because the Outdoor Unit Stopped
There is no homeowner symptom that proves low refrigerant by itself.
If Refrigerant Is Low
The cause should be located and repaired rather than treating repeated recharge as maintenance.
15. Severe Icing or Airflow Problems Are Affecting Operation
Normal frost and abnormal ice are not the same thing.
Normal Winter Frost
Frost can form during heating and should be managed by defrost operation.
Abnormal Heavy Ice Can Be Related To:
- Defrost-control problem
- Sensor fault
- Outdoor fan problem
- Refrigerant problem
- Drainage conditions
Outdoor Airflow Can Also Be Blocked By:
- Leaves
- Vegetation
- Snow
- Stored objects
- Improper enclosure
Do Not Chip Ice From the Coil
Coil fins and refrigerant tubing can be damaged easily.
16. The Heat Pump Has an Installation or Configuration Problem
Sometimes the outdoor unit is doing exactly what incorrect installation or controls are telling it to do.
Possible Installation-Related Problems Include:
- Incorrect thermostat configuration
- Improper wiring
- Wrong dual-fuel settings
- Incorrect outdoor lockout settings
- Improper refrigerant setup
- Restricted outdoor-unit location
- Equipment compatibility problem
New System That Has Never Worked Properly?
Review the installation and commissioning rather than assuming a major component suddenly failed.
System Stopped After a Thermostat Change?
Compatibility and installer settings deserve attention.
Safe Homeowner Checks When the Outdoor Unit Is Not Running
1. Check Thermostat Mode
Confirm the system is in the intended:
- Heat mode
- Cool mode
rather than Off, Fan-only or an unexpected backup mode.
2. Check the Setpoint
Make sure there is an actual heating or cooling demand.
3. Look for Emergency Heat
If Emergency Heat is selected, normal outdoor compressor heating may intentionally be disabled.
4. Record Fault Codes
Take a photo before resetting anything.
5. Check the Filter
A severely restricted filter can reduce system performance.
6. Check Registers and Returns
Make sure they are not blocked.
7. Inspect the Outdoor Area
From a safe distance, check for:
- Leaves
- Snow
- Vegetation
- Heavy ice
- Physical damage
8. Observe the Breaker
If it is repeatedly tripping, stop resetting it.
9. Note What the Indoor System Is Doing
Tell the technician whether:
- Indoor fan runs
- AUX Heat operates
- Furnace operates
- One ductless zone still works
These details can significantly narrow the diagnosis.
When Should You Shut the Heat Pump Off?
Stop operating the system when there is an obvious safety or damage concern.
Shut It Down and Arrange Service For:
- Smoke
- Burning electrical smell
- Repeated breaker trips
- Damaged or exposed wiring
- Severe grinding or mechanical impact
- Major outdoor-unit damage
Persistent Heavy Ice Also Deserves Attention
Do not continue trying to force operation indefinitely through a badly iced outdoor coil.
Do Not Open the Cabinet
The outdoor unit contains electrical and refrigeration components requiring qualified service.
Can You Keep Using the Heat Pump if the Outdoor Unit Is Not Running?
It depends on why it is off.
If the Thermostat Is Satisfied
There is nothing to fix.
If It Is in Normal Defrost
Allow the operating sequence to complete.
If a Dual-Fuel Furnace Is Intentionally Heating
The outdoor unit may remain off according to the control strategy.
If Emergency Backup Is Needed Because the Heat Pump Has Failed
A properly functioning backup system may provide temporary heat while service is arranged.
If that backup uses electric resistance heating, electricity consumption can increase substantially.
If Electrical Protection Is Tripping
Do not keep operating or repeatedly restarting the system.
Outdoor Fan Stopped vs Complete Outdoor Unit Stopped
This distinction matters.
Fan Stopped During Defrost
Can be normal.
Fan Stopped While Compressor Runs During Ordinary Heating or Cooling
May indicate an outdoor fan or control problem.
Fan and Compressor Both Stopped
Could be:
- No demand
- Control delay
- Backup-only mode
- No electrical power
- Control lockout
- Equipment fault
The Homeowner Does Not Need to Determine Compressor Operation by Touching the Unit
Observe and report the behaviour. Electrical and refrigeration testing belongs to professional diagnosis.
Outdoor Unit Not Running on a Central Ducted Heat Pump
The indoor blower may continue operating even if the outdoor heat pump is unavailable.
You May Notice:
- Air moving but little heating or cooling
- AUX Heat display
- Emergency Heat operation
- Outdoor unit silent
Full-Electric System
Electric resistance backup may temporarily maintain heat even while the outdoor compressor is unavailable.
Check Electricity Use
Extended resistance backup can use considerably more electricity than normal compressor heating.
Airflow Still Matters
Filter and duct problems can affect the operating conditions seen by the heat pump and should be included in diagnosis.
Outdoor Unit Not Running on a Ductless Heat Pump
Ductless systems can behave differently from conventional thermostat-controlled central systems.
Check the Indoor Unit
Look for:
- Fault code
- Status light
- Correct mode
- Setpoint
Indoor Fan Operation Does Not Prove Outdoor Operation
The indoor fan may behave differently depending on:
- Mode
- Demand
- Fault condition
- Manufacturer controls
Power Architecture Varies
Do not assume every mini-split has separate indoor and outdoor breakers or identical wiring arrangements.
Outdoor Unit Problems on Multi-Zone Heat Pumps
Several indoor units can share one outdoor compressor system.
If Every Zone Stops Heating or Cooling
A shared outdoor, power, communication or system-level problem becomes more likely.
If Only One Zone Has a Problem
A complete outdoor-unit failure becomes less likely when other connected zones continue operating normally.
The issue may involve:
- Individual indoor unit
- Zone sensor
- Communication
- Branch component
- Control
This Is a Useful Diagnostic Clue, Not a Universal Rule
Multi-zone system architecture varies between manufacturers.
Outdoor Unit Not Running on a Dual-Fuel Heat Pump
A furnace operating while the outdoor heat pump is off can be completely intentional.
The Control Strategy May Switch to the Furnace Based On:
- Outdoor temperature
- Heating demand
- Configured changeover point
- Equipment condition
Do Not Assume the Heat Pump Is Broken Because the Furnace Is Running
First determine whether the current control strategy is intentionally using fuel heat.
Unexpected Behaviour Deserves Diagnosis When:
- The furnace runs during conditions where the heat pump previously operated.
- The heat pump never operates anymore.
- Fault codes appear.
- Operating cost changes unexpectedly.
How Does a Technician Diagnose a Heat Pump Outdoor Unit That Will Not Run?
The goal is to identify why outdoor compressor operation is not occurring rather than immediately replacing whichever component looks expensive enough to be blamed.
1. Confirm the Complaint
Determine:
- Heating or cooling mode
- Indoor temperature
- Setpoint
- Outdoor temperature
- Whether backup heat is active
2. Review Fault Codes and History
Stored faults can identify intermittent conditions that are not present during the service visit.
3. Confirm Electrical Supply
Professional testing can evaluate:
- Supply voltage
- Breaker and disconnect circuit
- Connections
- Internal protection
4. Confirm Control Demand
Determine whether the indoor controls are actually commanding outdoor operation.
5. Check Communication
Particularly on inverter and ductless systems.
6. Check Outdoor Controls
Evaluate:
- Control board
- Switching components where applicable
- Inverter
- Sensors
- Protection history
7. Evaluate the Outdoor Fan
Distinguish a fan fault from normal defrost behaviour.
8. Evaluate Compressor Operation
Use manufacturer-appropriate electrical and operating tests.
9. Check Airflow
Evaluate:
- Indoor filter
- Indoor blower
- Outdoor coil
- Outdoor fan
10. Evaluate Refrigeration Conditions Where Required
Professional diagnosis may include pressures, temperatures and manufacturer-specified operating data.
11. Identify the Root Cause
The repair should address why the unit stopped, not merely clear a fault and wait for it to return.
What Affects the Cost to Repair an Outdoor Unit That Is Not Running?
The symptom describes many possible repairs, so there is no responsible universal repair price.
Cost Can Depend On:
- Diagnosis
- Control or sensor repair
- Electrical component
- Outdoor fan motor
- Inverter or control board
- Compressor
- Refrigeration-system repair
- Refrigerant
- Parts availability
- Warranty coverage
A Control Fault and Compressor Failure Are Not the Same Repair
Diagnosis should happen before quoting a major component.
Bernoulli Diagnostic Appointment
The current diagnostic appointment charge for an existing heat pump is $135.
Repair labour, replacement parts, refrigerant and additional materials are separate.
Should You Repair or Replace the Heat Pump?
An outdoor unit being off does not itself mean replacement.
Repair Often Makes Sense When:
- The fault is isolated.
- The system is otherwise reliable.
- Parts are available.
- Warranty applies.
- The equipment performed well before the failure.
Replacement Deserves More Consideration When:
- A major compressor or inverter failure is confirmed.
- The equipment is older.
- Major refrigerant leaks or coil deterioration also exist.
- Repairs have become frequent.
- Parts are difficult to obtain.
- The system was poorly sized or designed from the beginning.
Do Not Replace a Heat Pump Because of a Tripped Breaker Without Diagnosis
The actual fault could be very different from complete equipment failure.
How Can You Reduce Outdoor-Unit Problems?
Keep Outdoor Airflow Clear
Remove ordinary loose debris around the equipment without opening the cabinet.
Do Not Cover a Working Heat Pump
A heat pump needs outdoor airflow during heating and cooling seasons.
Keep Filters Clean
ENERGY STAR currently recommends cleaning heat pump filters when visibly dirty or when the equipment indicates filter service is required.
Watch for Persistent Ice
Normal frost should clear through defrost. Heavy ice that remains should be investigated.
Address Repeated Fault Codes
Do not make power cycling the permanent maintenance plan.
Arrange Regular Professional Maintenance
Periodic inspection can identify airflow, fan, electrical, control and refrigeration concerns before they become complete loss-of-operation calls.
Heat Pump Troubleshooting in Metro Vancouver and Fraser Valley
Bernoulli Heating and Cooling provides heat pump troubleshooting across Metro Vancouver and Fraser Valley.
If the outdoor heat pump is unexpectedly not running, diagnosis can include thermostat demand, fault history, electrical supply, controls, communication, outdoor fan, compressor, inverter equipment, airflow and refrigeration-system performance.
The current diagnostic appointment charge is $135. Repair labour, replacement parts, refrigerant and additional materials are separate.
For a new heat pump installation or replacement project, estimates are free.
Call 604-518-4438 or email heatingbernoulli@gmail.com.
Explore local installation information:
Heat Pump Outdoor Unit Not Running: Frequently Asked Questions
Why is my heat pump outdoor unit not running?
Possible reasons range from normal thermostat or defrost operation to electrical, controls, inverter, fan, compressor, sensor or refrigeration faults.
Is it normal for the outdoor heat pump to stop?
Yes. It can stop when heating or cooling demand is satisfied or during certain control sequences.
Is it normal for the outdoor fan to stop in winter?
Yes during a normal defrost cycle. NRCan explains that the outdoor fan is commonly shut off temporarily while heat is directed to the outdoor coil to remove frost.
How long should defrost last?
Duration varies by equipment and conditions. It should be temporary and ordinary heating should resume afterward.
Why is steam coming from the outdoor unit?
Visible water vapour can occur normally as frost melts during defrost.
Why is the indoor fan running but the outdoor unit is off?
The indoor blower can operate independently. Possible reasons include thermostat settings, backup heating, control delays, outdoor power loss or equipment faults.
Can AUX Heat run while the outdoor unit is off?
It can depending on the system and operating condition. A backup source may maintain heating if normal heat-pump operation is unavailable.
Does Emergency Heat turn the outdoor unit off?
On many central systems, Emergency Heat locks out normal compressor heating and uses the configured backup source.
Why is my furnace running but the heat pump is not?
In a dual-fuel system this may be intentional according to the configured changeover strategy, or it can result from a heat-pump fault.
Should my heat pump run when it is below freezing?
Air-source heat pumps designed for those conditions can operate below freezing. Outdoor temperature alone does not mean Emergency Heat should be selected.
Why is my outdoor unit silent?
It may have no demand, be in a delay, be intentionally locked out or have lost electrical or control operation.
Does a silent outdoor unit mean the compressor is bad?
No. Compressor failure is only one possible cause.
Can the thermostat stop the outdoor unit?
Yes. Incorrect mode, configuration, wiring or control communication can prevent compressor operation.
Can changing the thermostat cause the outdoor unit to stop working?
Yes if the new thermostat is incompatible, wired incorrectly or configured for the wrong equipment type.
Why did the outdoor unit stop after a power outage?
The system may be in a protective restart delay, have a tripped circuit or have developed another power-related fault.
Should I reset the breaker?
Do not repeatedly reset a breaker that continues to trip. Repeated trips require professional diagnosis.
Can I install a bigger breaker?
No. The breaker must match the circuit and equipment requirements.
Why does the breaker trip when the outdoor unit starts?
Possible causes include compressor, inverter, fan motor, wiring or other electrical faults.
Can a bad outdoor fan stop the heat pump?
Yes. Required outdoor airflow is necessary for normal heat transfer, and controls may shut equipment down when conditions become abnormal.
Does the fan always run when the compressor runs?
No. Defrost is an important example where the outdoor fan commonly stops temporarily.
What if the fan never runs in cooling mode?
If normal cooling demand is present and the outdoor fan remains stopped, arrange diagnosis rather than continuing to operate the equipment.
Can leaves stop the outdoor unit?
Heavy debris can restrict airflow and contribute to poor operation, although it does not explain every no-start condition.
Can snow stop a heat pump?
Snow that blocks airflow or drainage can create operating problems. Keep required clearances open without damaging the equipment.
Can I cover my outdoor heat pump in winter?
No. A heat pump operates during winter and requires outdoor airflow.
Can heavy ice make the outdoor unit stop?
Abnormal icing can reduce heat transfer and contribute to protection shutdowns.
Should I pour hot water on an iced heat pump?
Avoid improvised de-icing methods that can damage equipment or create refreezing. Persistent heavy icing requires diagnosis.
Can I chip ice off the outdoor coil?
No. Coil fins and refrigerant tubing can be damaged.
Does dirty indoor airflow affect the outdoor unit?
Yes. The indoor and outdoor sides are part of one refrigeration system, so inadequate indoor airflow can affect operating conditions.
Can a dirty filter make the outdoor unit shut down?
A severe airflow restriction can contribute to abnormal system operation and protection events.
Can closed registers stop the heat pump?
Closing too many registers can increase duct restriction and reduce system airflow.
Can low refrigerant prevent outdoor operation?
Refrigerant faults can trigger protective shutdowns, but an outdoor unit being off does not prove low refrigerant.
Should I add refrigerant?
No. Refrigerant work requires professional diagnosis and the cause of any loss should be identified.
Can a refrigerant leak cause fault codes?
Yes. Abnormal refrigeration conditions can trigger system protection depending on the equipment.
Can a bad control board make the whole outdoor unit dead?
Yes, although power, wiring, sensors and communication should also be tested before a control board is condemned.
Can a bad inverter make the compressor look dead?
Yes. On inverter-driven equipment, the compressor depends on the drive electronics for controlled electrical power.
Can a compressor be good if it is not running?
Yes. Another component or control condition may be preventing it from operating.
Can a bad compressor make the entire outdoor unit stop?
Yes in some fault conditions, but compressor failure needs to be confirmed through testing.
Can a capacitor cause the outdoor unit not to run?
Some conventional equipment uses capacitors for motor starting or operation. Modern inverter systems often use different electronic architectures, so this is not a universal heat-pump component.
Can a bad contactor stop the outdoor unit?
Yes on systems using a contactor or similar switching component to energize outdoor equipment.
Does every heat pump have a contactor?
No. Electrical and control architecture varies, particularly with inverter systems.
Can a sensor shut down the outdoor unit?
Yes. Heat pumps use sensors and protective logic to prevent operation under abnormal conditions.
Should I bypass a sensor to test the system?
No. Do not bypass equipment safety or protective controls.
Can indoor and outdoor units lose communication?
Yes. Communication faults are common diagnostic categories on modern ductless and inverter heat pumps.
Can one mini-split head work while another does not?
Yes. A local indoor-zone problem can affect one head without proving a total outdoor-system failure.
If all multi-zone heads stop, is the outdoor unit bad?
A shared outdoor, power, communication or control problem becomes more likely, but diagnosis is still required.
Why does my ductless indoor unit show a fault light?
The controller may be reporting a sensor, communication, outdoor-unit or other system fault. Record the code or flashing pattern.
Should I unplug or power-cycle a ductless system?
Follow manufacturer instructions. Repeated power cycling can erase useful information without correcting the cause.
Can a power surge damage the outdoor unit?
Electrical disturbances can affect control and inverter electronics.
Can rain stop a heat pump?
Outdoor equipment is designed for exterior installation, but electrical damage, flooding or severe storm damage is not normal.
Can water inside the outdoor electrical compartment be dangerous?
Yes. Visible electrical water damage should be evaluated before the equipment is operated.
Should I turn the heat pump off if I smell burning?
Yes. Stop operation and arrange professional evaluation.
Should I turn it off if the breaker keeps tripping?
Yes. Do not repeatedly reset it.
Should I turn it off if the outdoor unit is grinding?
Yes. Severe mechanical noise can indicate a problem capable of causing additional damage.
Can I keep using Emergency Heat until repair?
Where the system has properly functioning backup heat, temporary backup operation may maintain comfort. Follow the equipment guidance and arrange repair because electric resistance backup can materially increase electricity use.
Can I keep using my gas furnace if the heat pump is down?
A properly functioning dual-fuel system may be able to use the furnace as temporary heating while the heat pump is unavailable.
Can I cool the house if the outdoor unit is not working?
No normal refrigeration-based air conditioning is available when the outdoor heat pump cannot operate.
Will the indoor fan alone cool the house?
It can circulate indoor air but cannot provide normal compressor-based cooling.
Why does warm air come from the vents with the outdoor unit off?
Electric resistance backup or a furnace may be providing heat.
Can the system heat with the outdoor unit off?
Yes when an independent backup heating source is operating.
Why did my electricity use increase after the outdoor unit stopped?
If electric resistance backup replaced normal heat-pump heating, electricity consumption can increase substantially.
Does an outdoor-unit fault mean I need a new heat pump?
No. Many outdoor electrical, fan, sensor and control faults are repairable.
When does replacement make more sense?
Replacement becomes more relevant when a major failure occurs on older equipment with repeated repairs, deteriorated coils, poor system design or limited parts support.
Should I replace the outdoor unit only?
Sometimes, but the new outdoor unit must be compatible with the retained indoor equipment and control system.
Can I replace only the fan motor?
Yes when diagnosis confirms the fan motor is the failed component and an appropriate replacement is available.
Can I replace only the control board?
Yes when the diagnosis confirms board failure and the rest of the system is suitable for repair.
Can I replace only the inverter?
On systems where the inverter assembly is serviceable separately, that may be possible. Confirm the diagnosis and parts availability.
Should compressor failure be confirmed before replacement?
Yes. Compressor replacement is a major repair and should be supported by appropriate electrical and refrigeration diagnosis.
How does a technician know whether the unit has power?
A qualified technician can safely test supply voltage, electrical protection, disconnect circuits and internal electrical conditions.
How is an inverter diagnosed?
Manufacturer procedures can include fault history, supply testing, compressor electrical evaluation, communication checks and inverter-specific measurements.
Does technician diagnosis include refrigerant pressures?
When refrigeration conditions are relevant, pressure and temperature measurements may be used together with airflow and equipment data.
Why should airflow be checked before refrigerant conclusions?
Airflow affects heat transfer and therefore the refrigeration conditions being measured.
Can an installation problem make the outdoor unit shut down?
Yes. Electrical, control, refrigerant, airflow and equipment-compatibility problems can originate with installation.
What if the heat pump has never worked properly?
Review sizing, equipment match, installation and commissioning rather than treating every new symptom as ordinary equipment wear.
What if the problem began right after maintenance?
Tell the service provider. Recent electrical, control or equipment work can be relevant to diagnosis.
What if it only happens when it is very cold outside?
Outdoor-temperature-related protection, capacity, defrost and control strategy can all affect winter operation. The model’s actual operating data should be reviewed.
What if it only happens in cooling?
Mode-specific controls, refrigerant conditions, sensors or equipment faults can affect one mode differently from another.
What if it heats but will not cool?
The compressor may still be functional. Reversing valve, controls and other refrigeration issues can create mode-specific faults.
What if it cools but will not heat?
Similarly, heating-only problems can involve reversing valve, defrost, sensors, controls or refrigeration conditions without proving compressor failure.
How can I help the technician diagnose an intermittent problem?
Record fault codes, outdoor temperature, thermostat mode, setpoint, sounds and whether the indoor fan or backup heat was operating when the outdoor unit stopped.
Should I take a video?
A safe video of abnormal sound or operating behaviour can be useful, provided you do not open or touch the equipment.
Can annual maintenance prevent every outdoor-unit failure?
No. Components can still fail, but maintenance can identify airflow, coil, electrical and operating problems earlier.
How do I keep the outdoor unit clear?
Maintain the manufacturer-required space around the equipment and remove ordinary loose vegetation and debris without opening the unit.
Does ENERGY STAR recommend clean heat pump filters?
Yes. Current ENERGY STAR guidance recommends cleaning filters when visibly dirty or when the filter indicator calls for service.
Is electrical heat pump work regulated in BC?
Yes. Technical Safety BC classifies residential heat pumps as regulated electrical equipment and states that most installations or upgrades require an electrical permit.
Can refrigerant work also be regulated?
Yes. Technical Safety BC identifies additional refrigeration requirements for systems that meet specified equipment, refrigerant and building conditions.
Does Bernoulli diagnose outdoor-unit problems?
Bernoulli Heating and Cooling provides heat pump troubleshooting across Metro Vancouver and Fraser Valley, including outdoor electrical, fan, compressor, inverter, control, airflow and refrigeration-related diagnosis.
How much is the diagnostic appointment?
The current diagnostic appointment charge is $135. Repair labour, replacement parts, refrigerant and additional materials are separate.
Are replacement estimates free?
New heat pump installation and replacement estimates are currently free.