Why Do Gas Pumps Run Slow? Ultimate Guide

The most frequent customer complaints about gas stations that you can easily see are “There is nothing I hate more than gas pumps slow on a hot summer day” or “ only so slow when I’m in a hurry?” 

You can find thousands of such complaints online about gas stations, almost all flow-related. So, why do gas pumps run slow? How do you solve it? This article will provide all the answers to this problem.

Why Do Gas Pumps Run Slow?

Why Do Gas Pumps Run Slow

Why are gas pumps so slow? It can be the faulty pump & suction system or fuel filter that trigger such an issue. Submerged pumps and mechanical leak detectors are also possible causes.

Verifying there are no system leaks is the first step in diagnosing your problem. The following list of typical reasons for slow flow is provided even when there are no leaks.

Clogged Fuel Filters 

Fuel System Issue

Why is the gas pumping so slow? The most popular culprit behind a slow flow is a clogged filter, which can happen when your filter is too old. Filter problems can become more and more obvious and serious.

Filters don’t have an expiration date, but they are usually replaced once a year.

The filter should be replaced every six months should you dispense more than 100,000 gallons each month. This simple routine maintenance can help avoid problems caused by outdated filters.

A dirty tank and pump can also lead to a clogged filter. If you have time to change the fuel filter regularly, try to clean or change your fuel pump and tank, too.

Also, when the diesel engine filter is clogged frequently, there could be an algae problem. Algae will appear as rust on the old filter and directly affect the fuel, leading to bad gasoline overtime.

Just follow a routine maintenance schedule for your gas filter, and your problems should go away over time.

You may need additional fuel treatment, cleaning, and polishing of the diesel tank to avoid this situation as well.

Submerged Pumps and Mechanical Leak Detectors

A mechanical leak detector might appear in the UST system if your pump is having trouble starting and causing slow pumps.

You must ensure no physical leaks by checking the dispenser and the device’s auxiliary path.

When there is a significant temperature change, the pressure in the pipeline can drop, causing the gasoline to contract.

 This is why there may not be any obvious leaks. The internal check valve of a submersible pump can have other problems that contribute to pressure drop.

The mechanical leak detector can eventually stop working, resulting in the system going into sluggish flow even without pressure loss.

This can be remedied by turning on the pump, allowing the system to pressurize again, then performing a leak test.

Faulty Pump & Suction Systems

In addition, the pump’s condition and age can be the reason for the question: why are some gas pumps so slow? A submersible pump rarely fails without any prior signs.

A professional technician can only identify a slow flow problem when the pump loses power, or the rotor fails.

Each fuel supply hose in the intake system usually has a different path to the gas tank. When you have a slow flow problem, it can be due to the dispenser piping or pump.

Suppose all the dispensers at one suction site fail; there might be something wrong in the fuel tank that needs cleaning.

Filtering is not a requirement for all the suction dispensers, but all must come with at least one fuel shield.

Other problems may include gas leaks due to loose fittings or internal problems with the pump unit.

How To Speed Up A Slow Gas Pump?

Conduct Flow Stress Tests

A properly performed fuel flow check can ensure that your station doesn’t have a slow flow. All you need to do is perform a performance test of your device.

Track the time frames your customers pump gas at your station for the best time to take the test.

Since your test results will indicate performance, off-peak hours are the optimal time to check your fuel flow.

As more nozzles operate, the pump configuration becomes more and more strained.

Calculate customer refueling times during peak operations at refueling stations to get a more accurate picture of pump capacity.

To calculate gallons per minute (GPM), divide the fuel injection rate by the chronograph display time.

Let’s say the result shows that your fuel flow is significantly lower than 10 GPM at peak hours.

Your pump configuration may be undersized, forcing customers to leave with less than full gas or have to stop at another station to refuel earlier than usual.

Veeder-Root Solutions

If your submersible pump is under 2 HP, upgrading to a 2 HP model can give you the extra fuel flow required to increase productivity and maximize income.

Using a second pump as needed during high demand can boost the pump capacity in various pump designs with intelligent control.

By using the double pump only when necessary, the system also provides smart redundancy in the event of a primary pump failure.

In addition, the smart controller can alternately control the pump to manage your fuel levels in both tanks, making it convenient for your fuel inventory and logistics management.

Adding a second STP to your high-volume product line can be a relatively affordable way to raise your volume, depending on your tank configuration.

If you’ve determined that your front yard throughput is below average, Veeder-Root may assist you in looking at options for increasing your pump’s capacity.

Contact Professionals  

If the filter, nozzle, and pump are strong enough, but slow flow persists, it may be time to review whether your current equipment is outdated and whether you need a new pump and dispenser or not.

An effective solution is to talk to knowledgeable and experienced experts. They can aid you in upgrading your equipment in a way that suits your budget.

They will also recommend updating your pumps and gas dispensers to keep your gas station upgraded at a low cost.


Customers will not return to your station if they often encounter slow gas pumps here. Instead, they will most likely move to the opponent’s station across the road.

Consumers do not know and do not want to know all aspects or factors that affect the fuel dispenser flow rate. Why do gas pumps run slow?

So all you need to do is find out the reason and take different actions to speed up the flow, thereby increasing the quality of the customer experience.

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