Troubleshooting Roundup Sprayer Woes: Tips & Quick Fixes

Premixed Roundup spray bottles are convenient and effective for ridding your flower bed or sidewalk cracks of pesky weeds and grass. However, more often than not these handheld sprayers fail to work when you need them. All that mixed herbicide sits in there with no way for you to safely or evenly apply it. Talk about frustrating.

All is not lost. This article is going to examine the common Roundup sprayers and spray bottles, how they work, and how to fix them when they don’t. With some patience and luck, you can be back up and spraying in no time.

Different Types of Roundup Sprayers

Before we delve into troubleshooting, it’s essential to understand the different types of Roundup sprayers and the basic components of each one. Note: Many other brands offer pre-mixed sprayers as well. Ortho, Sevin, Spectracide, etc. These troubleshooting tips and methods will work on many of those as well.

Roundup Ready-To-Use Sprayers

Trigger Spray Bottles

These simple Roundup sprayers rely on a conventional trigger spray gun like a Windex bottle. They are comprised of the product bottle, suction tube, and trigger assembly.

Electric Sprayers

Ready to spray, pre-mixed Roundup also comes in a version with a battery-powered electric hand sprayer (Essentially the same as the sprayer shown in the video below). These are similar to manual trigger sprayers, but you simply push a button to spray rather than pull a trigger. 

Pump ‘N’ Go 

The “Pump ‘N’ Go” sprayer from Roundup is a hand pump sprayer that comes with premixed Roundup herbicide. These operate essentially the same as the reusable hand pump sprayers on the market.

Roundup Brand Hand Pump & Backpack Sprayers

There are also Roundup brand sprayers that do not contain any premixed herbicide. These are merely typical hand pump sprayers with the Roundup brand slapped on them.

Roundup also has a backpack sprayer. Again, it is essentially a basic backpack sprayer with the Roundup brand on it. The way to troubleshoot and repair these is no different than with a normal generic hand pump or backpack sprayer. I’ve already covered this in detail and these articles. So if you’re Roundup sprayer is one of these versions reference these articles for help:

Backpack Sprayer Troubleshooting It

Hand Pump Sprayer Not Working

Common Roundup Pre-Mixed/Ready-to-Use Sprayer Issues and Solutions

Issue: Nothing is Working!

I would recommend checking these things before diving into further troubleshooting. I call these the “slap your forehead” issues or the “oh, duh” things we forget to check. We have all been there when nothing is working and we don’t even have the thing plugged in!

Solution: First make sure the sprayer lid is turned to the “on position” and the spout is open. If you have an electronic wand, check that there is not a piece of paper blocking the battery terminals. These are often installed to prevent people from spraying or draining the battery in the store. Also, check that there are batteries in the sprayer wand. 

Issue: Clogging

Clogging is by far the most common issue with trigger gun style or electric wand Roundup sprayers and spray bottles. This is often the result of chemical residue build-up in the spray tip. A good sign of residue building up in the nozzle is when you see a distorted or uneven spray pattern coming out of the nozzle. 

Solution: Soak the spray tip in warm soapy water to loosen any residue. While you have the sprayer nozzle submerged you can gently work the trigger back and forth. Sometimes this is all that it takes. If it is still plugged use a small pin to gently remove any remaining debris from the spray tip. 

Persistent plugs might require you to soak in soapy water for a while then take the nozzle/sprayer head apart and clean it with an old toothbrush. You can find a more elaborate guide to cleaning nozzles in this article

If cleaning your nozzle thoroughly does not help the situation, then there are some other things to check. First, examine your hose. Ensure that there are no kinks in the hose/tubing from the lid of the tank to the spray gun. Then check that the spout on the lid of the bottle is open. Sometimes these are only partially open or they get jerked shut when the hose is pulled.  

Finally, check inside the tank. There is a suction tube that connects to the outlet on the lid and drops into the tank. This tube may need to be unplugged or reconnected to the lid. 

Issue: Air Lock/No Prime

Sometimes you will pull the trigger and nothing happens. You check for clogs in the sprayer, check for kings, etc. and nothing works. The culprit is usually air.

Solution: Unscrew the lid, hold the end of the hose that goes into the tank above the trigger gun or wand, and stretch out the hose so that it is straight. Depending on if you have an electronic wand or manual sprayer, hold the button or pull the trigger multiple times. Reinstall the lid onto the tank and pull the trigger again while keeping the trigger below the tank. 

After pulling the trigger multiple times It should start spraying again. Once it starts working you can lower the sprayer bottle/tank below the trigger gun and continue spraying. 

You should note that if you have an electric spray wand and you do not hear the motor running then you need to replace the batteries. 

Maintenance Tips for Your Roundup Sprayer

When you buy a Roundup premixed spray or other brand of pre-mixed pesticide, you are hoping that when the tank runs out you can simply buy the refill and attach your sprayer wand and get back to work. However, these sprayers are notorious for not lasting very long. My recommendation would be to buy concentrated pesticides or herbicides and a hand pump sprayer to use. These last longer and will be less expensive in the long run. 

If you already have a pre-mixed Roundup sprayer do not worry, with some maintenance you can keep it working for at least a few refills. Here are the recommended maintenance tips:

  1. Clean After Each Use: Take the suction hose, lid, tube, and spray wand off of the bottle/tank. Use fresh water to flush out the assembly and rinse everything out. 
  2. Storage: Keep the sprayer inside when not in use. If possible, avoid keeping the sprayer in a garage or outbuilding where it will freeze/thaw. Keep out of the sun when not in use.
  3. Take the batteries out when not in use. 

Final Thought

Pre-mixed Roundup sprayers are a convenient tool. They are prone to malfunction but with these tips, you should be able to get your sprayer working again. 


I have more than a decade of experience using, building, studying, and testing sprayers in several applications. With the knowledge I have gained I want to provide straight forward and detailed answers for DIY homeowners, farmers, and commercial turf and tree care pros.

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