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Is your Honeywell air conditioning (AC) system not working properly? Has your Honeywell thermostat stopped responding or displaying error messages? Don’t sweat it – this comprehensive troubleshooting guide will help you get your Honeywell AC back up and running in no time.

We’ll cover common issues like the AC not turning on, not blowing cold air, not responding to the thermostat, freezing up, short cycling, and more. We’ve compiled expert tips from HVAC technicians and easy, DIY fixes you can perform yourself to diagnose and resolve problems with your Honeywell AC.

Why Is My Honeywell AC Not Working?

There are several reasons why your Honeywell cooling system may stop functioning correctly. Here are some of the most common issues:

Thermostat Problems: The Honeywell thermostat controls your entire AC system. Issues like incorrect temperature readings, blank display screens, unresponsive buttons, and losing WiFi connectivity can prevent the AC from turning on.

Honeywell Thermostat Troubleshooting

Since Honeywell thermostats control AC system operation, problems with these devices can completely stop your cooling. Try the following troubleshooting tips if your Honeywell thermostat is malfunctioning:

Honeywell Thermostat Display Is Blank

Check Power Connections: Make sure the thermostat is properly wired and receiving continuous power. Verify that the wires are securely inserted into the correct terminals.
Reset and Reboot Device: Reset the thermostat to factory settings or reboot it by removing the thermostat body from its wall plate for 20 seconds. This may clear any software glitches.
Replace Batteries: All Honeywell thermostats require new batteries periodically. Low battery power causes display, connectivity and performance issues.
Inspect Wires: Examine the system and thermostat wires for damage. Frayed, cracked or loose wires disrupt connectivity and power delivery.

If display issues persist, you’ll need to replace the Honeywell thermostat. Contact Honeywell support for additional assistance.

Honeywell Thermostat Not Responding

Check Error Codes: Inspect your thermostat interface or user manual for any error codes. These indicate specific sensor or hardware problems.
Clean Screen and Buttons: Clean dirt, debris and grime off the thermostat screen and buttons with a microfiber cloth. This improves screen responsiveness.
Test with Separate Thermometer: Verify thermostat accuracy by placing an independent thermometer nearby and comparing temperature data. Replace the device if readings are vastly different.
Load Defaults and Reconfigure: Reload factory default settings then carefully reprogram your temperature schedules, mode and fan settings. This clears any programming errors.
Upgrade Firmware: Download and install the newest software and firmware package for your thermostat model. Updates often fix unresponsive bugs.

For touch screen thermostats, touch calibration issues may require professional recalibration or panel replacement.

Honeywell Thermostat Not Controlling AC

If your thermostat settings, mode, schedules and commands fail to activate the AC, try these tips:

Check Wiring: Inspect the wiring connections to ensure all labeled thermostat terminals and color-coded wires match the wiring diagram specifications for your HVAC system. Rewire incorrectly connected cables.
Test Component Voltage: Using a multimeter, check your transformer, circuit boards and components for proper operating voltage. Low voltage prevents activation.
Reset and Program Thermostat: Reset your Honeywell thermostat to erase any erroneous settings or programming commands then carefully reconfigure device preferences.
Bypass Thermostat: To isolate thermostat issues, bypass the device by connecting the R and Y1 terminals. If the furnace or AC engages, replace the faulty thermostat.
Replace Batteries: While testing, provide the thermostat temporary 24-volt low voltage power using an external battery source wired to the common C terminal. If the AC works properly, install fresh batteries.

Repeated control issues require professional diagnosis and replacement of the defective Honeywell thermostat.

Central Air Conditioning Not Working

Problems within the central cooling equipment itself also cause operation failure. Try these DIY troubleshooting tips if your entire central air conditioning system fails to start:

AC Not Powering On

Check Electrical Panel: Inspect your main electrical service panel for any tripped circuit breakers or blown fuses related to the AC equipment and thermostat circuits. Reset breakers and replace fuses accordingly.
Verify Power Switch: Locate the service disconnect box to ensure the exterior condensing AC unit power switch did not accidentally get turned off. Flip the switch back on.
Test Voltage: Using a multimeter, check the low-voltage transformer, thermostat wires, contactor coils, capacitors and fan motor windings for proper voltages to isolate power defects.
Inspect Wiring: Make sure external condensing unit and internal air handler power wires did not become damaged or disconnected. Secure loose wire connections.
Reset Circuit Breakers: If voltage testing uncovers defects, turn off the equipment power and reset related breakers. Allow 5 minutes before restoring power to avoid overloading.

Power loss requires diagnosis and repair of faulty electrical infrastructure by an HVAC technician.

AC Not Blowing Cold Air

Clean Filters: Very restricted air filters block airflow, overwork the AC system and impede heat transfer. Routinely replace dirty filters.
Check Vents and Registers: Ensure all vent and ductwork registers are open and unblocked in the rooms you want cooled. Close off unused rooms.
Remove Debris: Clean dirt, leaves or debris from the outdoor AC unit fins and coils to maximize airflow and refrigerant cooling.
Check Refrigerant: Call an HVAC technician to check refrigerant pressures. Low levels indicate leaks that need repairing and recharging the refrigerant system.
Measure Vent Air Temp: Using ductwork thermometers, measure vent discharge air temperature. If it’s only slightly cooler than room temperature, there’s an airflow, refrigerant or metering device fault present.

Refrigerant charging, leak repairs or installing larger AC equipment may be needed to resolve inadequate cooling issues.

AC Short Cycles On and Off

It’s concerning when your AC constantly turns on and off in rapid succession. Try these tips to halt short cycling:

Clean Filters and Coils: Dirty components force the frozen evaporator safety switch to engage and shut the AC off. Proper cleaning restores normal operation.
Check Supply Voltage: Have an HVAC technician confirm electrical voltage is within normal operating range. Too high/low voltage damages the compressor and triggers short cycling.
Inspect Blower Fan: Ensure debris is not obstructing the blower fan blades. Damaged, off-balance or seized fan motors also contribute to short cycling.
Monitor Thermostat Settings: Adjust thermostat temperature and humidity settings to wider parameters that avoid excessive cycling based on slight ambient condition changes.
Test Compressor Amp Draw: Use multimeter clamps to measure compressor amperage. Unusually high/low readings indicate compressor valve defects requiring repair.

Replacing damaged AC components like fan motors, valves, driers, controls and sensors will stop harmful short cycling.

Honeywell Split AC Troubleshooting

Split ACs contain separate outdoor condenser and indoor evaporator units. Try these split AC-specific troubleshooting tips if your Honeywell model isn’t working correctly:

Honeywell Split AC Not Turning On

Check Remote Settings and Battery: Ensure your Honeywell Split AC remote contains fresh batteries and the proper mode, fan speed and temperature settings selected to power on the system.
Test Unit Voltage: Using a multimeter, verify the indoor unit and outdoor compressor are both receiving 208-230V power from the electrical panel and circuits.
Reset Unit: Flick the indoor unit power switch off for 20 seconds to cycle the devices internal circuitry. Switch power back on.
Clear Airflow Restrictions: Remove furniture blocking split AC units or wall-mounted evaporator air intakes. Move drapery and plants away from AC airflow paths.
Confirm Condensate Drainage: Ensure smooth condensate drain pan and pipeline operation. Blocked outflow triggers float safety switches that deactivate the AC.

Electrical defects require diagnosis and repair by a certified HVAC technician.

Honeywell Split AC Not Cooling

If both the outdoor and indoor split AC units activate but blow ambient temperature air, try these troubleshooting tips:

Verify Thermostat Operation: Double check your Honeywell thermostat wiring and settings are properly configured to call for cooling operation when below the setpoint.
Conduct Thorough Cleaning: Clear dust buildup on condenser coils and blower fans so refrigerant can transfer heat efficiently again.
Check Refrigerant Pressures: Using HVAC gauges, a technician must check refrigerant levels and confirm the compressor is creating sufficient pressure differential for heat transfer and evaporation.
Monitor Voltage: During attempted operation, use a multimeter to monitor transformer and component voltages for stability within operating ranges. Faults require repair.
Inspect Cabinet Seal: Ensure a proper air seal still exists between the split AC wall sleeve and interior cabinet for conditioned air supply and proper return airflows.

Refrigerant leaks, low system pressures, electrical issues and airflow obstruction all hinder split AC cooling capacity. Schedule service accordingly if DIY efforts fail.

Portable and Window Honeywell AC Troubleshooting

More compact window mount or portable Honeywell AC units incorporate the major components into a single chassis for targeted room cooling. However, these models also experience common operation failures.

Honeywell Window and Portable AC Not Powering On

Inspect Fuses: Check and replace any blown cartridge fuses inside the AC chassis that prevent device activation after pressing the power button.
Verify Outlet Voltage: Use a multimeter to confirm adequate 120V power supply from the electrical socket powering the portable or window AC unit.
Reset GFCI Outlet: If plugged into a ground fault circuit interrupter outlet, reset the GFCI if tripped. If issues persist, use a different outlet.
Check Power Cord: Untangle, securely connect and inspect the power cord for damage preventing voltage from reaching the AC appliance.
Clean Air Filter: Remove and clean excessively dirty reusable air filters that obstruct overall chassis airflow and operation.

Replacing blown fuses, damaged power cords or faulty controllers restores functioning. Multiple room ACs tripping breakers requires upgrading inadequate electrical service panels.

Honeywell Portable AC Not Cooling Properly

Empty Water Tank: Ensure the condensation collection tank is regularly emptied. Full tanks trigger float switches that deactivate cooling.
Clear Airflow Restrictions: Reposition the AC unit away from walls, furniture and drapery that blocks critical air intake and outlet airflow.
Clean Air Filter and Fins: Remove dirt accumulation on filters and heat exchanger fins that lowers operational efficiency.
Reduce Room Heat Load: Eliminate heat generating appliances and lighting near the portable AC. Close windows and lower temperature setting.
Check Compressor Function: Listen for steady compressor operation cycles while cooling is engaged. Irregular on-off cycling signals issues.

Room ACs that frequently freeze up have low refrigerant charges likely requiring professional recharge service.

Honeywell AC Not Working After Power Outage

Storms, electrical overloads or grid maintenance can suddenly cut power to your Honeywell HVAC equipment. But even after utilities restore electricity, air conditioning may fail to restart due to:

Tripped Circuit Breakers: Check your main electrical panel and reset circuit breakers powering the AC system.
Blown Fuses: Replace any blown fuses inside your cooling equipment or electrical panels.
Lost Thermostat Programming: Reprogram your thermostat schedule, fan settings, mode and preferences after extended power loss overrides memory.
Control Board Resets: HVAC control boards often require manual rebooting and reloading system parameters if power outage durations exceed 15 minutes.
Safety Lockouts Engaged: Heating elements and compressors containing automatic lockout functions for overcurrent/thermal situations typically need manual resets to restart after power loss.
Condensate Drain Overflow: Power loss shuts off condensate pumps allowing indoor evaporator coils to overflow drainage pans once electricity returns. Water damage trips safety switches. Professionally unblock drain lines and dry equipment.

While you can reset devices and check for damage, HVAC technicians should fully inspect equipment safety mechanisms before restoring central AC operation after sustained power loss.

Getting Professional Honeywell AC Repair Service

If you’ve made several unsuccessful troubleshooting attempts, HVAC experts possess the advanced tools, testing capabilities and component access needed to properly diagnose your Honeywell air conditioning problems.

We recommend contacting skilled heating and cooling technicians anytime issues involve:

Refrigerant pressure or temperatures exceeding expected operating ranges
Electrical shorts tripping internal safety cutouts
Visible burning or charring smell from controls or motors
Abnormal noise, vibration or leaks
Total air conditioning failure despite previous proper operation

Certified technicians have extensive equipment and controls knowledge to pinpoint issues and recommend repairs or upgrades needed to keep your Honeywell cooling system operating reliably for years to come.

Preventing Future Honeywell AC Problems

While some AC component failures come without warning, practicing proactive maintenance helps minimize repairs and extend equipment lifespan for lasting cooling:

Change Filters Regularly: Dirty filters make systems work excessively hard leading to failures. Swap filters out every 1-3 months based on usage.
Clear Debris: Keep outdoor condenser coils, fins and fans clear of leaves, dirt and obstructions so airflow stays unimpeded.
Check Drain Lines: Periodically pour water into indoor unit drain pans and inspect exterior termination points to ensure free condensate drainage.
Monitor Runtime Trends: Take note of runtime duration increases that indicate lowering performance. Diagnose underlying issues promptly.
Perform Annual Tune-Ups: HVAC technicians methodically inspect all components, test operations, clean elements, check refrigerant and verify safety performs peak seasonal cooling.

Following the maintenance tips and diagnostic suggestions within this Honeywell AC troubleshooting guide keeps home cooling operating comfortably all summer long. Reach out anytime with questions!

I hope this comprehensive Honeywell AC troubleshooting guide gives you greater confidence tackling cooling issues on your own. But for complex electrical, refrigeration and airflow-related breakdowns, connect with professional heating and cooling technicians to get dependable repairs completed promptly. Stay cool!

Frequently Asked Questions About Honeywell AC Repairs

Why does my Honeywell AC keep freezing up?

If your indoor evaporator coil frequently frosts or freezes, common causes include low refrigerant levels, dirty filters/coils, blower fan failures and improper thermostat operation. Have an HVAC technician thoroughly inspect your system.

Why is my Honeywell thermostat not connecting to WiFi?

Check for WiFi network disruptions and verify the thermostat password was entered correctly. Weak router signals, incorrect passwords, outdated firmware and device malfunctions interrupt connectivity.

Why does my Honeywell AC smell bad when turned on?

Burning plastic odors typically come from excess dust/debris accumulation on motors and blower components. Musty smells often stem from mold growth on wet evaporator coils or drainage pans. Both require cleaning or replacement.

How can I recalibrate my Honeywell smart thermostat screen?

Access the touch calibration menu within your thermostat settings. Carefully follow prompts to touch red target points appearing on-screen so sensors can sync responses. Call support if issues persist afterwards.

Why does my Honeywell AC keeps blowing fuses?

Frequently blown fuses suggest an electrical overload or short within system controls, motors or compressors. HVAC technicians must isolate the electrical fault and repair damaged elements before replacing fuses.

Why won’t my Honeywell AC turn off?

If your system runs continuously regardless of thermostat commands, common culprits include stuck relay switches, control board failures not terminating operation calls and incorrectly calibrated temperature sensors.

How do I reset my Honeywell smart thermostat?

Locate the reset pinhole button on the back of the device and use a paperclip to press the internal reset switch for 5+ seconds until the display reboots and prompts configuration routines.

Why does my Honeywell thermostat keep losing power?

Frequent power loss suggests wiring issues like loose terminal connections, mismatched wiring colors, low system voltages and incorrectly-sized power cables. Electrical repairs often resolve intermittent power problems.

How much does it cost to replace a Honeywell thermostat?

While prices vary by region and model, homeowners typically pay $125-$325 in labor and materials to completely remove old and install updated Honeywell smart thermostats with full configuration assistance.

Honeywell AC Not Working? Troubleshooting Guide for Honeywell Thermostat Issues