Step-By-Step Instructions to Fix the Nordson® F1 Fault Code on ProBlues

Q: What if the F1 fault code won’t go away?

If you have followed all the steps to troubleshoot an F1 fault error without success, there may be a more serious issue at play. Fortunately, we do offer support for Nordson glue melters that can help you fix the issue and get you back up and running.

Q: Can I still run my machine with an F1 fault showing?

No. When an F1 fault is active, the Nordson system automatically disables the heaters for your safety. If you try to run the melter without addressing the issue, it could not only put you in danger but also damage the machine. Always fix the problem and reset the fault before trying to resume operations.

Q: How do I clear an F1 fault on my Nordson ProBlue?

To clear an F1 fault, follow the steps outlined in the article above to resolve the problem. You can temporarily dismiss an F1 fault by pressing the Clear/Reset key, but the heaters will still remain off. If after two minutes the machine still detects the fault condition, the fault will reappear on the LED screen.

Q: How can I prevent future F1 faults?

The best way to avoid an F1 fault is with regular preventative maintenance and proper operation of the equipment. We do offer an adhesive equipment maintenance program , so you do not need to worry about trying to complete this maintenance in-house.

Q: Where can I find replacement parts if needed?

You are in luck. At Hotmelt.com, we carry a wide range of both Nordson OEM parts and compatible parts for Nordson melters . These parts can help you get your melters back up and running. If you have more questions, feel free to contact us .

Q: Do I need to contact Nordson to resolve an F1 fault?

Not necessarily. Many F1 faults can be fixed in-house by following the proper instructions, but we understand this may not always be the case. Whether you feel you do not have the expertise to fix the F1 error or the fault is a recurring problem, it may be time to contact a qualified service technician. The ProBlue series has been discontinued by Nordson, and they have also been phasing out their support services for the ProBlue product line. If you need assistance, our team does offer technical support for these melters, just contact us .

How to Troubleshoot Nordson® F1 Fault Code on the ProBlue

If your Nordson glue machine is displaying an F1 Fault code, you're not alone. This is one of the most common Nordson fault codes across the ProBlue® 4, ProBlue® 7, ProBlue® 10, and ProBlue® 15 series. The Nordson glue machine F1 fault can bring production to a screeching halt, but in many cases, it is a relatively easy fix.

Our team walks you through what the Nordson F1 Fault means, the most frequent causes, and step-by-step instructions to fix it and get your system back up and running.

What Does the Nordson F1 Fault Mean?

The F1 fault code on a Nordson ProBlue glue machine is an issue with your RTD or resistance temperature detector not getting a reading. The RTD is what senses and gauges the temperature of the tank, hoses, or applicators. It gives these components power to heat up.

To protect your machine, the F1 fault code will trigger the shutdown of the heaters, so it does not overheat. The fault code will be displayed on the LED screen, and the melter will record the fault in the fault log.

Causes of the Nordson F1 Fault Code

A Nordson fault code of F1 could be the result of numerous issues, with some more serious than others. Some potential causes of an F1 fault code on a ProBlue could be:

Cause	Details
Disconnected RTD	Hose/gun unplugged or loose connection
Open Circuit (OP)	Broken wire or failed RTD
Short Circuit (SH)	Damaged insulation or pinched wires
Physical Damage	Melted/corroded sensor

Diagnosing the F1 Fault Code

Before you jump in and start trying to fix the F1 fault on a Nordson ProBlue melter, it is important that you understand the full extent of the error and its cause. The fault log will help you diagnose what is wrong with your Nordson melter. It can tell you the type of fault that occurred, the last ten faults to occur, and the heater hours since the fault occurred.

Go to the Fault Log

Your first step to fixing the melter should be to review the fault log to get more information about the cause of the error.

1. Press and hold the Setup key.

2. Scroll to Parameter 2 (Fault Log) with the right‐display scroll key ↑/↓.

You can review up to the last ten fault codes. Older log entries beyond that are overwritten.

Review the Fault Log

Fault codes are made up of four digits with the following meanings:

1. A number detailing the affected component (1-6)

Number on Display	Affected Component
1	Tank or hose/gun 1
2	Manifold or house/gun 2
3	Hose 3 or gun 3
4	Hose 4 or gun 4
5	Hose 5 or gun 5
6	Hose 6 or gun 6

2. & 3. A fault has occurred (This will always display as "-F")

4. The type of fault (1 for a F1 fault code)

For example, a F1 fault code that is the result of an issue with hose 3 would display as 3-F1.

If your ProBlue F1 fault is the result of a disconnected hose and applicator pair, the last two fault logs will show up with the F1 code. This first log entry is for the gun, and the second is for the hose.

See the Elapsed Heater Hours

You can also find out the number of heater hours that have elapsed since a log entry was created.

Simultaneously press both right-scroll keys ↑/↓ on an entry.

The hours will be shown on the right display.

Check the RTD Fault Type

Another important step to diagnosing the issue is determining if the RTD fault is related to an open circuit or a short circuit issue.

While the F1 fault code is displayed, press both right-display scroll keys ↑/↓.

If OP appears, it means it is an open circuit issue. If SH appears, it is a short circuit issue.

If at any point the fault log is left open for two minutes without any keys being pressed, the machine will return to the automatic scan mode. You can also press the Setup key twice to exit.

Step-by-Step: How to Fix the Nordson ProBlue F1 Fault Code

Now that you have a better understanding of the error and its cause. It is time to actually fix the F1 fault. Before doing any repairs, it is imperative that you power off and disconnect your Nordson melter. This action can help keep you and anyone else around the melter safe.

Follow these steps to diagnose and troubleshoot the F1 fault code on your Nordson Problue.

Perform a Basic Inspection.

Check the connections and reseat RTD plugs at the melter and component.
Inspect the cables for cuts, burns, and pinches.
Ensure the hoses and guns are fully connected.
Check the main board for visual damage to the J7 plug-in.
Measure the RTD resistance across RTD leads using a multimeter. The expected resistance should be between 130-145 Ω at room temperature (~21°C or 71°F).

Reading	Meaning
OL	“Open Line” most likely the result of a broken wire or faulty connector
Near 0Ω	Failed RTD that needs a replacement
130-145 Ω	The RTD is functioning properly. Replace the main board if the fault persists.

Turn on Override Mode

Heat the melter to allow the removal of parts in the tank and manifold.

Hold the Setup and Tank keys.
Turn the Cycle Control Switch from OFF to ON.

The left display will show flashing dashes that indicate that the melter is heating in override mode. It will automatically shut off in 20 minutes. The system should be monitored during this time, and you should follow all safety recommendations outlined in the Problue manual.

Replace an RTD

To replace an RTD, you should start by de-energizing and relieving the pressure before taking the next steps.

For the Tank RTD:

Open the pump door.
Pull the retention clip to slide out.
Clean the slot and apply the thermal compound to the new RTD tip.
Reinstall and reclip.

For the Manifold RTD:

Isolate the pump from the manifold by rotating the isolation valve handle to its full vertical position (valve closed).
Remove the three pump‐mounting bolts from the front of the pump body.
Rotate the top of the pump slightly toward the front of the melter and then pull the pump up and away from the manifold. **The face of the pump body contains two M6 threaded holes. Bolts can be threaded into these holes to gain leverage when removing the pump.
Remove the air line from the back of the pump.
Lift the pump clear of the melter.
Remove the RTD from its retention slot.
To replace the RTD and pump, do these same steps but in reverse.

Before replacing the pump, ensure that the cross‐over tube is in place between the pump and the manifold.
Before replacing the RTD, apply the thermal compound.

This step can be more involved, so refer to the owner's manual for specifics.

Clear & Restart

Once the fix is complete, you will want to clear the fault code and reset the system.

Press Clear/Reset.
Press Heater (LED on).

You should monitor the system for five to ten minutes and verify that the temperatures rise before attempting to use the equipment.

Need More Support?

If you're seeing recurring F1 faults on Nordson machines or the fault won't go away, it might be time to call in a professional. We offer equipment troubleshooting support for Nordson systems, including the different ProBlue systems.

If you are able to fix the F1 fault code, set yourself up for success in the future. Avoid any unnecessary downtime by keeping the correct spare parts for Nordson ProBlue on hand. You should also document each step in a maintenance log for future reference.

Hotmelt.com is not affiliated with the Nordson® Corporation. All OEM part numbers are for reference only. Nordson® is a registered trademark of the Nordson® Corporation.