Troubleshooting Tips for Asphalt Plants

At N2P, we believe in supporting Asphalt Plant operators – even if the components in the plant are not our product. We are always ready to assist you with problems that may arise in the course of your day, and we have compiled a few tips here to help you get back up and running quickly.

Before you call for help, read this helpful article which details a few examples of issues our team have dealt with recently and a couple of tips that will ensure that if you need to speak to a support person, we can work together efficiently.

Information Is Power – Trust Your Error Codes

It’s a good idea to take a photo of the control screen as soon as an issue comes up – and note down everything you see. That way as you try different fixes you will be able to note if there are any changes occurring on the digital panel, make sure to also note if the codes change as you try various fixes.

Your control panel will also have lights and alarms that will be triggered in specific ways according to the issue present. Record what you see, and record if and when changes occur.

Oftentimes going to your manual to look up an error code or alarm will immediately give you a handle on why your plant is not operating properly.
Isolate Your Issue
Discovering the context of your problem will allow you to better identify your solution. For instance, if you have a conveyor belt that won’t start, check to see if it’s a solitary belt that’s not working – or is it all the belts? 

Take a look at every stage of your process, noting what IS working can go along way towards isolating where the issue is occurring.

Note Your Context
Think about when the plant was running and what has occurred in the interim – has there been a maintenance crew in? Did you have painters come through? Or was there a weather event or a power cut?


Recently we had a call from a plant operator who was flummoxed by a plant stoppage. The programme had been running for 20 years and suddenly it wasn’t working, a local electrician was called in who then replaced every component in the Programmable Logic Controller (PLC) box. The plant was stopped for 2 days, costing money and pushing back projects.

The electrician then called us at N2P; after chatting through what was happening, we directed the electrician to check the lights on the PLC; sure enough, one was flashing – the plant start light. Going to the manual and checking the information for that light revealed that the problem was that someone had hit the Emergency Stop button.

A further chat revealed that an external E-Stop on the outside of the plant had been accidentally hit by a painting crew that had been on site.


Be sure to check all lights and error codes in the manual, then think about context. What has happened out of the ordinary between the plant working and stopping?

  1. Check The Whole Line

Everything in your plant is connected, so if one component is not functioning, try to isolate the issue by checking everything on the line; figuring out what IS working creates a process of elimination that will eventually lead you to the fault.


A customer recently got in touch because the Bitumen Pump in their plant had stopped operating. We discovered there were no error codes present and no alarms or lights signaling a direct fix. Once this was ruled out, we had the operator check the PLC to see if the output was turning on. This led us to rule out a fault in the software and to enquire as to whether the relay that enables the drive was operating correctly – we discovered that the relay was not turning on.

At this point, we knew what was working and what was not working; we had the operator call in an electrician who checked the wiring, ruling out an electrical issue. The next port of call was to check the bitumen tank levels; it was discovered that the tank was at high level, and this is what was shutting the pumps down.

Through a process of elimination, the problem was isolated and solved – educating the operator on what may work to fix such a problem if it occurred again.


The issue may not be with the component that is not working; start with checking error codes and work your way through all the other components that are connected to the part of your plant that has stopped operating.

Before You Call For Help

  1. Note what IS working, is the issue localised to a single motor, pump, drum or belt? Or is the problem widespread?
  1. Check if you are receiving an error code. Is there an alarm? Flashing lights? Check the whole screen for directions to faults, overloads, low air pressure etc. – take notes and a photo, and be sure to take another after you have tried a fix.
  1. Check whether your scheduled maintenance is up to date. Could you have a component that should have been checked or replaced?

N2P are always happy to help, so check your error codes, make your notes and call us if you still need assistance.