Skip to Content

Roundup pump sprayer is not working? Troubleshooting guide

The Roundup pump sprayer is one of the best you can find on the market.

In fact, we’ve previously recommended it as one of the best pump sprayers for weeds. And we still think it is worth your money.

Unfortunately, you might encounter a few issues when using the pump sprayer. Noteworthy, these issues are pump-specific rather than design flaws.

Nevertheless, the problems can be pretty inconvenient, especially when you need the pump for time-sensitive tasks such as herbicides or pesticide control.

We have compiled information on troubleshooting and repairing your pump sprayer when it stops working.

Reasons why your Roundup pump sprayer is not working

There are several reasons why your Roundup pump sprayer might stop working.

These include:

  1. The lid is not closed properly
  2. Wrong pumping mechanism
  3. Insufficient levels of liquid in the tank
  4. A blocked nozzle
  5. Damaged sprayer parts

How to fix a Roundup pump sprayer that is not working?

If your Roundup pressure sprayer isn’t working, the troubleshooting tips below can help you identify and fix the issue:

1. The lid is not closed properly

Roundup pump sprayer lid

One of the major issues causing your Roundup pump sprayer not to work might be the tank lid.

The way the sprayer works is that it compresses air in the tank to create pressure. The pressure is then used to move the liquid from the tank out through the nozzle.

If the lid is not closed correctly, the air in the tank will not be compressed, as the pressure will escape. As a result, your pump will not spray the liquid in the tank.

Therefore, before you start pumping, you should ensure that the lid is closed snugly such that the air won’t escape.

Aside from the lid, it is also possible that air could be leaking through the hose, where it is attached to the tank lid.

READ ALSO:  What happens if you run a lawnmower without oil?

Like with the tank lid, you need to ensure that the hose seal is secured snugly to the pump, thus preventing air from escaping.

2. Wrong pumping mechanism

Another issue that can cause your Roundup pump sprayer not to work is the wrong pumping mechanism. This is specific to the backpack garden sprayers with piston pumping mechanisms.

With the piston pump, air enters the pressure chamber when you move the lever (pumping handle) up.

Then, when you move the handle down, the air in the chamber is pushed into the tank, creating pressure.

Therefore, to create pressure in the tank, you must move the handle up and down (from and to the highest and lowest points it can go).

Unfortunately, some people make the mistake of pumping from the center position of the handle, which does not create any pressure in the tank.

Therefore, if you have any issues with your Roundup garden sprayers, you should adjust your pumping mechanism and see if anything changes.

With the proper pumping mechanism, the lever becomes harder to move as the pressure inside the tank builds up.

3. Insufficient levels of liquid in the tank

Insufficient liquid levels are another reason your Roundup hand pump sprayer won’t work.

To spray, you must have enough liquid in the tank, which is suctioned out by the pressure created as you are pumping.

As the levels of the liquid fall down, the spray output declines until a point where no more liquid can be pumped out. Therefore, you need to increase the liquid in the tank to continue spraying.

Unfortunately, the opposite can also be an issue, causing the sprayer not to work.

As already stated above, the pump sprayer works through pressure creation, and this can only happen if there is sufficient space for air to be compressed in the tank.

READ ALSO:  3 propane torches for burning weeds

If there is too much liquid in the tank, you won’t be able to create enough pressure, thus causing the spray nozzle not to work. To avoid this, you should not overfill your tank.

Most sprayers will come with a water level where the maximum capacity is marked.

However, if your sprayer does not have a maximum level, filling the tank about three-quarter’s the capacity will work just fine.

4. A blocked nozzle

A blocked nozzle is another common issue that can cause your Roundup pump sprayer to stop working.

The nozzle can be clogged by debris introduced into the tank through water (if you use unclean or unfiltered water).

It can also happen if you allow the nozzle to touch the ground when using the pump, thus clogging the pores with dirt.

Roundup Pump Sprayer

Another possible cause of clogging is the solidification of herbicides, pesticides, fertilizer, or other solutions you use with the pump. Again, this will happen if you don’t clean the pump well after using it.

Fortunately, a clogged nozzle is very easy to fix. You just need to unscrew the nozzle and use a needle or a toothpick to pick out any debris blocking the output.

However, when doing this, you should be careful not to expand the nozzle hole, as this can cause it to start leaking when spraying.

Aside from poking the nozzle, you can dissemble the entire hose from where it is attached to the tank.

Then, break the hose down into individual components unscrewing each hose part from the other (you can use the manual to figure out how to unscrew them).

You can now push a high-pressure water stream through each component, unclogging any debris causing the sprayer not to work. After unclogging, re-assemble the hose and attach it to the sprayer.

READ ALSO:  Is Ryobi a good brand and are the tools worth buying?

5. Damaged sprayer parts

Unfortunately, another reason your pump sprayer might not be working is if there are any damaged components.

Some of the most likely components to be damaged include the hose, nozzle, sprayer handle, and pumping mechanism.

Fortunately, fixing some of these damaged parts might be possible by replacing them with spare parts.

For example, you can purchase the Roundup pump sprayer repair kit, which comes with gaskets and O-rings for the pumping mechanism and spare nozzles.

However, you should only attempt to repair your sprayer pump if you know what you are doing.

If not, you should take the pump to the store you purchased it from for repairs or ask for recommendations for a repair technician from your local gardening shop.

Final thoughts

The Roundup pump sprayer is an important tool that can help you in many gardening tasks, such as weeding. Therefore, it can be pretty frustrating when it fails to work.

Fortunately, with the information above, you can identify and fix most of the issues causing the sprayer not to work.

However, if you are unable, you should hire the services of a professional to repair the sprayer for you.

Aside from repairing your pump sprayer, you should also regularly maintain it by keeping it clean, dry, and lubricated.

This prevents damage to important components such as the nozzle, hose, and pumping mechanism, which can be costly to fix.