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Common Printing Issues

This article explains the most common printing issues in unTill Air and provides detailed troubleshooting steps to help identify and resolve them. Most printing problems are related to incorrect printer configuration, network connectivity issues, unsupported hardware, or device permissions.

1. Printer not printing​

In some situations, no ticket is printed and no error message appears in the POS. This usually indicates that the printer is reachable, but the printing workflow or routing configuration is incorrect.

The possible causes are:

"Do not print" mode enabled​

unTill Air allows printers to be disabled using the "Do not print" option. When this option is enabled, printing requests are ignored without generating an error message.

How to fix:

  1. Go to Back Office > Hardware > Printers.

  2. In Printer settings, disable the "Do not print" checkbox.

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For more information about printer settings, refer to this page.

Printer redirected to another printer​

A printer may be configured to redirect print jobs to another printer. If the destination printer is offline, incorrectly configured, or not intended for printing, no output may appear.

How to fix:

  1. In POS > Printer screen,

  2. Check if there are any active redirections for the relevant printer.

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For more information about printer management in POS and redirection, refer to this page.

Printer not assigned to a screen or digital bill​

When using digital bills or screen-related printing, the printer must be assigned correctly. If no printer is linked to the screen configuration, tickets may not print.

How to fix:

  1. Go to Back Office > Hardware > Screens

  2. Check your screen configuration and ensure that a printer is assigned for bill printing.

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For more information about screen settings management, refer to this page.

Items not assigned to a preparation printer​

Preparation printers only print items assigned to them. If articles are not connected to the correct preparation printer, the printer will remain idle even though orders are created successfully.

How to fix:

  1. Go to Back Office > Hardware > Printers.

  2. Verify that the printer is marked as a preparation printer.

  3. Check the article assignments and make sure all required items are assigned to the correct preparation printer.

Preparation area misconfiguration​

Preparation areas define which items are routed to specific printers. Incorrect preparation area rules may prevent tickets from printing.

How to fix:

  1. Go to Back Office > General > Preparation areas.

  2. Review the configured rules for the relevant preparation area and verify that articles, categories, and printers are linked correctly.

Incorrect preparation area setup is a common reason why kitchen or bar printers do not receive tickets.

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For more information about preparation areas, refer to this page

2. Connection issues (most common)​

Connection issues are the most common cause of printing failures in unTill Air. Printers communicate through the local network, which means the POS device and printer must be able to reach each other directly.

If the network connection is unstable or incorrectly configured, printing may fail completely or work intermittently.

The possible causes are:

Incorrect IP address or port​

Each network printer uses its own IP address and communication port. If the wrong IP address or port is configured in unTill Air, the printer cannot receive print jobs.

To fix this, verify the configured IP address and port in Back Office > Hardware > Printers and compare them with the actual printer network settings.

You can also test the connection by entering the printer IP address in a browser on the POS device. If the printer administration page opens, the printer is reachable on the network.

If the page does not open, the printer may be connected to another network, offline, or using a different IP address.

The POS device and printer must always be connected to the same local Wi-Fi network.

Many printers also allow printing a network configuration ticket directly from the device, which can help verify the current IP address and communication settings.

Printer connected to a different network​

Printing only works when both the POS device and printer are connected to the same local network environment.

Common examples include:

  • The POS device connected to one router while the printer is connected to another
  • The POS device connected to guest Wi-Fi
  • The printer connected through a mobile hotspot

To fix this, connect both the POS device and the printer to the same private Wi-Fi network and avoid using separate or isolated access points.

In some cases, restarting both the printer and the POS device after reconnecting to the network may help restore communication.

Mesh or repeater network usage​

Mesh networks and Wi-Fi repeaters can interrupt or block local device communication. Even when internet access works correctly, printers may become unreachable from the POS device.

To fix this, use a standard Wi-Fi router whenever possible and connect printers directly to the main network instead of through repeaters or mesh systems.

Weak Wi-Fi signal or obstacles​

Poor signal quality can cause delayed printing, incomplete tickets, or intermittent connection problems.

This is commonly caused by:

  • Large distance from the router
  • Walls or metal obstacles
  • Weak router hardware

To fix this, move the printer and POS device closer to the router, improve Wi-Fi coverage, or replace weak networking equipment with a stronger router.

Overloaded or weak router​

Some routers become unstable when many devices are connected simultaneously, which can affect printer communication.

To fix this, restart the router, reduce unnecessary network traffic, or replace older hardware with a more powerful router suitable for stable local communication.

Public network usage​

Public Wi-Fi networks often block local communication between connected devices for security reasons. In these cases, the POS device may not be able to communicate with the printer even if internet access is available.

To fix this, always use a private local network for POS and printer communication.

Some mobile operating systems block local network access unless permission is granted manually.

This issue is especially common on:

  • iOS devices
  • Sunmi devices

The possible causes are:

Local network permission disabled​

If the unTill Air application does not have permission to access the local network, printers cannot be discovered or reached.

How to fix on iOS:

  1. Open the device settings
  2. Find the unTill Air application
  3. Open Permissions
  4. Enable Local Network access

How to fix on Sunmi devices:

  1. Open the device settings
  2. Find the unTill Air application
  3. Open Permissions
  4. Enable Local Network access

After enabling permissions, restart the application and test printing again.

4. Unsupported printer​

Not all printers are compatible with unTill Air. The platform is designed to work with ESC/POS-compatible printers.

The possible causes are:

Unsupported printer model​

Some printers use proprietary protocols and cannot process ESC/POS commands correctly.

How to fix:

  • Use a supported printer model
  • Verify compatibility before installation
  • Prefer officially supported ESC/POS printers

Different protocol (not ESC/POS)​

If the printer does not support ESC/POS communication, printing may fail completely or produce unreadable output.

How to fix:

  • Replace the printer with a compatible model
  • Alternatively, enable Simple mode

Simple mode may provide limited functionality depending on the printer model, but full compatibility is not guaranteed.

5. Empty (blank) ticket prints​

In some cases, the printer feeds paper correctly but the printed ticket is blank.

This issue is usually related to paper orientation or incorrect paper width configuration.

The possible causes are:

Paper inserted incorrectly​

Thermal printers only print on one side of the paper. If the paper roll is inserted incorrectly, the ticket will remain blank.

How to fix:

  1. Open the printer cover
  2. Remove the paper roll
  3. Reinsert the roll with the thermal side facing the print head
  4. Close the printer cover
  5. Perform a test print

Incorrect paper width configuration​

The configured paper width in the system must match the actual printer paper width.

Common paper widths:

  • 80 mm
  • 72 mm
  • 56 mm

How to fix:

  1. Verify the printer specifications
  2. Check the configured paper width in unTill Air
  3. Make sure both values match

Simple mode configuration issues​

Simple mode may require additional configuration adjustments depending on the printer model.

How to fix:

  • Review Simple mode settings
  • Verify printer compatibility
  • Test printing with and without Simple mode enabled

Although most printer communication happens locally, unstable internet connectivity may still affect synchronization and cloud communication.

The possible causes are:

No internet connection​

If the POS device cannot communicate with unTill Air services, some printing operations may not function correctly.

How to fix:

  • Verify internet availability
  • Restart the router if needed
  • Confirm that the POS device has active internet access

Poor internet connection quality​

Unstable internet may cause delayed synchronization, failed orders, or inconsistent printer behavior.

How to fix:

  • Use a stable private network
  • Avoid overloaded public Wi-Fi
  • Improve router quality and coverage

For stable printing performance, always use a reliable private local network with strong Wi-Fi coverage and supported ESC/POS printers.

If the issue persists after completing all troubleshooting steps, contact your reseller or support representative for further investigation.