Por favor, activa JavaScript en tu navegador para completar este formulario.

Start / Job Info – Step 1 of 6

Use this mobile workflow to isolate communication issues before replacing controls or boards. Complete the steps in order. If Tech Support follow-up is needed, submit the form while you are still on site whenever possible.

Do not start by changing boards or controls.

Most communication faults are caused by low-voltage/control wiring, loose connections, or bus communication problems rather than failed parts.

Tip: If the UI allows it, check Advanced Menu > Service > Run/Fault History and the last 10 system events before replacing parts.

Field process: Reinstall first. Then isolate the UI, indoor unit, outdoor unit, and control wiring using the guided steps below.

Mobile workflow: Job info → power verification → control type → reinstall → indoor/outdoor result → voltage or outdoor diagnostics → resolution/support.

Technician Name *

Nombre

Apellidos

Dealer / Company Name *

Job Name / Customer Name *

Technician Phone *

Technician Email *

What communication issue are you troubleshooting? *

Outdoor Communication Fault
Indoor Communication Fault
System Communication Fault
Not sure — guide me through system communication testing

Have you verified line voltage to all communicating equipment? *

Verify line voltage at each piece of equipment the system may attempt to communicate with before continuing.

Stop: Restore and verify line voltage to all communicating equipment before continuing. Communication testing is not valid until power is confirmed.

After correcting power, is line voltage now verified? *

Yes — line voltage is verified
No — stop troubleshooting

Select Yes only after voltage has been confirmed at all communicating equipment.

Guardar y reanudar más tarde

Control Type

Which control is installed? *

Legacy Control
Infinity/Evolution A Series Touch Screen
Infinity/Evolution B Series Touch Screen
Infinity/Evolution C Series Touch Screen

Legacy Control System Re-Installation

Step 1: Hold Advanced until the screen changes

Step 2: Scroll to Install

Step 3: Select Installation

Step 4: Select Re-install

Touchscreen Control System Re-Installation

Step 1: Press and hold the Service icon until it turns green

Step 2: Select Installation

Step 3: Complete full system installation

Step 4: Select Re-install

What was the re-installation result? *

Found all components and completed airflow test
Indoor unit was not found
Outdoor unit was not found

Select the result shown after performing the re-installation/full installation.

Guardar y reanudar más tarde

Communication Restored

Is the system operating correctly now? *

Yes
No — continue troubleshooting

Guardar y reanudar más tarde

Indoor unit Voltage Check

ABCD Plug Voltage Check

Step 1: Start at the indoor unit, remove the green ABCD plug from the board.

Use a Volt meter set for DC Volts.

Measure the voltage on pins A & B sticking out of the board.

Step 2: Measure DC voltage at A/B with plug removed *

Steady between 3.5–4.5 VDC
Fluctuating 1.0 VDC – 4.0 VDC
Steady less than 3.0 VDC

Expected board output is typically between 3.5–4.5 stead VDC at terminals A and B with the green plug removed from the board.

Most likely your indoor board is good.

You should check the 2 Low voltage wires between the Indoor unit and the USER Interface for shorts or breaks or you may want to take the USER Interface to the Indoor unit and connect it directly to the indoor unit with a short piece of Low Voltage wire to test.

Step 3: Reconnect plug and recheck A/B DC voltage *

Voltage fluctuates 2.5–4.5 VDC
Voltage fluctuates 0.0–2.5 VDC

Wait 60 seconds after reconnecting. Then measure A/B DC voltage with the plug connected.

You most likely have a low voltage short between your indoor unit & outdoor unit or a bad plug/outdoor board.

Remove the low voltage wires going to the Outdoor unit from the green plug, leaving just the User Interface and the Indoor unit connected. Re-check voltage on terminals A & B of the green plug.

Step 4: What is the result with the Outdoor unit low voltage wires removed from the Green ABCD plug? *

Voltage fluctuates 2.5–4.5 VDC
Voltage fluctuates 0.0–2.5 VDC

Wait 60 seconds after reconnecting. Then measure A/B DC voltage with the plug connected.

The issue is a short in the Low Voltage wires going to the Outdoor unit or the outdoor unit plug or board has failed.

Test the outdoor unit board output by removing the green plug and verifying 3.5 vdc – 4.5 VDC steady output on terminals A & B. If you have 3.5 vdc – 4.5 steady VDC, you most likely have a short in your Low voltage wires and the outdoor board is fine.

Most likely your indoor board has failed.

Outdoor unit Voltage Check

Guardar y reanudar más tarde

Outdoor Board Diagnostic – OHMS

In this exercise you will be required to test resistances in the 1,000s of ohms Ω. Please verify that your meter has the proper sensitivity to perform this task. To verify this, test the resistance through your body by pinching one lead of your meter in each hand with your fingers moist and the meter set to ohms Ω. If your meter shows a resistance it will work for this task. Otherwise it will not work for this purpose and you will need to get one that will in order to properly service this equipment.

Have you verified your meter can read resistance in thousands of ohms? *

Step 1: Turn outdoor unit power off *

Done

Ohm Test: A-B terminals

Only numbers in k-ohms should be entered below ……. (example 28.4) meter could read 28400 ohms = 28.4 k ohms NOTE: Your meter must be capable of reading in the thousands of ohms.

A-B resistance reading *

The reading was between 28k-34k ohms Ω
The reading was higher than 28k-34k ohms Ω
The reading was lower than 28k-34k ohms Ω

Measured OHM reading between terminals A-B on the board – Expected reading for 1 stage, 2 stage, & Variable speed = 28k – 34k Ohms Ω

A-C resistance reading *

The reading was between 16k-20k ohms Ω
The reading was higher than 16k-20k ohms Ω
The reading was lower than 16k-20k ohms Ω

Measured OHM reading between terminals A-C on the board – Expected reading for 1 stage, 2 stage, & Variable speed = 16k – 20k Ohms Ω

B-C resistance reading *

The reading was between 13k-15k ohms Ω
The reading was higher than 13k-15k ohms Ω
The reading was lower than 13k-15k ohms Ω

Measured OHM reading between terminals B-C on the board – Expected reading for 1 stage, 2 stage, & Variable speed = 13k – 15k Ohms Ω

5 Stage Inverter AOC Boards = A-B 15-17 K ohms Ω (old versions up to 141203) A-B 28-34 K ohms Ω (newer versions after 141203)

5-stage inverter AOC A-B resistance reading

The reading was between the values described above
The reading was higher than the values described above
The reading was lower than the values described above

Were all resistance readings within the prescribed values? *

Recheck resistance readings before proceeding

Guardar y reanudar más tarde

CONGRATULATIONS!!!

You have successfully corrected the issue. Sometimes wire can become corroded or not make good connection over time. By going through the previous steps you have corrected this issue.

CONGRATULATIONS!!!

You have determined a possible issue.

CONGRATULATIONS!!!

Sometimes a wire can become corroded or not make good connection over time. By going through the previous steps you have corrected this issue.

CONGRATULATIONS!!!

You have successfully corrected the issue. Sometimes wire can become corroded or not make good connection over time. By going through the previous steps you have corrected this issue.

Wire Issue

Earlier we determined that the User Interface could successfully communicate with the Indoor Unit and not the outdoor unit. The only variable we changed in-between was the wire used for the communication. The lack of Communication from outdoor unit to the indoor unit has been isolated to the wire/connections connecting the two pieces of equipment.

Describe what you observed

Include wiring changes made, meter readings, UI messages, and any remaining symptoms.

Do you want Tech Support to contact you about this job? *

Choose Yes if the issue is unresolved, the test could not be completed, or support is needed.

Tech Support Follow-Up

Are you still on site? *

YES, I am on the jobsite
NO, I am not on the jobsite

Can you receive a text message at this phone number? *

Outdoor Unit Model Number *

Outdoor Unit Serial Number *

Indoor Unit Model Number *

Indoor Unit Serial Number *

User Interface Model Number *

User Interface Serial Number *

User Interface Software Version *

Photo: outdoor unit data plate

Drag & Drop Files, Choose Files to Upload

Optional but recommended for Tech Support follow-up.

Photo: indoor unit data plate

Drag & Drop Files, Choose Files to Upload

Optional but recommended for Tech Support follow-up.

Photo: User Interface screen

Drag & Drop Files, Choose Files to Upload

Upload the fault, software, model, or install result screen if available.

Photo: wiring or meter reading

Drag & Drop Files, Choose Files to Upload

Upload control wiring, board terminals, or meter reading if it helps explain the issue.

System Events

List fault/event codes and occurrence counts *

Advanced Menu > Service > Run/Fault History. Include each listed device and the last 10 system events if available. Example: 103 – Low indoor temp Zone 1 – 1 occurrence.

Did the reinstall find all installed components and complete airflow test? *

Did the UI locate the indoor unit? *

If your USER Interface is displaying “Enter DEMO MODE” this means the USER Interface is not communicating with the Indoor unit. Try switching the 2 wires used on terminals A & B between the USER Interface and the Indoor unit or you may want to take the USER Interface to the Indoor unit and connect it directly to the indoor unit with a short piece of Low Voltage wire to test.

Did the UI locate the outdoor unit? *

Communication restored — confirm resolution *

Done

Confirm the equipment and control are now operating correctly. The issue may have been caused by a loose connection or wire movement during testing.

Outdoor Communication – AB Test

This model has a transformer or Inverter outside that powers the control board. The instructions below will help walk you through providing power to the User Interface for testing.

Step 1: Turn off power to outdoor unit *

Done

Step 2: Disconnect ABCD plug from outdoor unit *

Done

Step 3: Connect outdoor ABCD plug to back of Infinity Touch *

Done

Step 4: Connect temporary C/D jumper wiring *

Done

Using a separate 2–4 ft piece of new thermostat wire, connect white to C and red to D on the green plug connected to the User Interface, with A and B still connected.

Step 5: Connect jumper to condenser board *

Done

Connect the other end of the 2–4 ft jumper to the condenser. Connect red to UTIL/24-UTIL and white to C on the control board to power the User Interface for testing.

Step 6: Turn on power to indoor unit *

Done

Step 7: Turn on power to outdoor unit *

Done

NOTE: The Outdoor unit will NOT be found because it is not connected. If the User Interface says the outdoor unit is not found the indoor unit and User Interface have successfully communicated.

Outdoor Communication – ABCD

ABCD – Green, Yellow, White, Red – “Get Your Wiring Right” or “Give Your Wife Roses”

Step 1: Connect UI to outdoor ABCD plug *

Done

Step 2: Turn indoor unit power back on *

Done

Step 3: Check communication with indoor unit from outside *

Done

NOTE: The Outdoor unit will not be found because it is not connected. If the User Interface says the outdoor unit is not found the indoor unit and User Interface have successfully communicated.

What message does the User Interface display? *

“Cannot Communicate with equipment”
“Outdoor Unit not found”

What message does the User Interface display? *

“Cannot Communicate with equipment”
“Outdoor Unit not found”

Outdoor Communication – Second Attempt

Step 1: Reconnect green plug with wires attached *

Done

Step 2: Turn outdoor unit power on *

Done

Step 3: Perform reinstall at wall control *

Done

Was the outdoor unit found? *

Outdoor Communication – Second Attempt *

Done

Reconnect the green plug with wires attached

Step 1: Turn outdoor unit power on *

Done

Step 2: Perform reinstall at wall control *

Done

Was the outdoor unit found? *

Do you want Tech Support to contact you about this job? *

Add Text and Images to Your Form With Ease

To get started, replace this text with your own.

Guardar y reanudar más tarde

Your form entry has been saved and a unique link has been created which you can access to resume this form.

Enter your email address to receive the link via email. Alternately, you can copy and save the link below.

Please note, this link should not be shared and will expire in 30 days, afterwards your form entry will be deleted.

Copy Link

Email *