How Long Can You Run A Pressure Washer? A Must Read Guide

Helen Skeates
Helen Skeates
21 min read

Every homesteader should be familiar with the dos and don’ts of pressure washing. You should keep in mind that if you utilize these machines for commercial cleaning services, you may have to replace them sooner than intended if you misuse them. As a result, if you don’t strictly adhere to the directions in the user handbook, your pressure washer may experience mechanical issues or perhaps stop working altogether.

What Are Some Common Ways Pressure Washer Pumps Get Damaged?

Cavitation, overheating of the pump, and incorrect settings of the unloader valve are the three most prevalent causes of pump damage in pressure washers.

10 Easy Checks to Stop Your Pressure Washer Being Ruined


When water flowing through a pump begins to bubble up, this is known as cavitation. Pressure washer pumps can be seriously damaged if used with bubbles in the water, which is against their design.

There are numerous ways in which cavitation can occur. In situations where the pump’s water supply is constrained in some way, or when the pump’s GPM demands are not met,

It is possible to have cavitation if the pressure washer needs 4 GPM of water to run properly, but only gets 3.7 GPM, for example.

An other example would be, if the pressure washer is fed by a garden hose that is either too small in diameter or too long. It’s also a concern with light-weight hoses because they can kink and shut off the water supply. The water supply to the machine could be compromised in any of these conditions.

Dirty water filters could also induce cavitation by blocking up the water entrance and preventing water from flowing freely. Aside from the clogged inlet fittings, unsecured inlet fittings leak and allow air into the lines, preventing water flow.

Listen to see whether cavitation has been a problem for your motor. When cavitation is present, pump noise increases. After hearing a slamming or shuttering sound, it’s likely that the pump may need to be replaced sooner rather than later.


Pressure washers are designed to work at high pressures.. A high-pressure stream of water shoots out from the wand’s tip as soon as you turn on the pressure washer. For as long as the machine is running, water will be spouting from the wand at high pressure.

It is inevitable that the machine’s water will escape if you release the trigger while it is still running. The pump switches to bypass mode since it can no longer remove water from the machine.

When the bypass switch is engaged, the water is redirected in a circular fashion. Due to the water’s inability to leave, it circulates at high speed and pressure until the machine is shut down or the trigger is pulled once again.

When the pump is left in bypass mode for an extended period of time, it will overheat. The high pressure of the circulating water causes the water to heat up to a very high temperature as a result of friction. This is something that can happen in a matter of seconds. Bypass mode shouldn’t be used more than 45 seconds at a time to avoid overheating the pump and damaging it.

Unloader Valve

The pressure washer pump might be seriously damaged if the unloader valve is configured incorrectly for the pressure washer.

Damage to a pressure washer pump can and can occur in any one of these three frequent methods, and the pump’s lifespan will be reduced as a result.

How long can you run a pressure washer?

Pressure washers should not be used for more than five minutes at a time. Between 3 and 5 minutes is a good range for the length of time. More than five minutes of continuous use of your pressure washer can result in overheating.

We’re sure you don’t want to spend a fortune fixing a grounded machine due of your carelessness. While taking a phone call in the middle of a cleaning routine is unavoidable, you should not use a pressure washer in bypass since it will divert your attention. As a result, shutting off the pump before doing any other work is the best advice we can give.

If you’re using a pressure washer, you’ll want to keep an eye on the GPM (gallon per minute) of the machine. Water supply must be at least 5.0 GMP for a pump rating of 5 gallons per minute. Cavitations, a phenomena in which a trigger gun creates a pressure spike, will occur if the pressure is too low. Pressure washers can be permanently damaged in extreme cases. The problem is that in order for these devices to function properly, they require a continuous supply of water. Overheating in a pressure washing machine can be prevented by making sure that the water flow is sufficient.

Do pressure washers overheat?

Yes. Overheating is a problem with pressure washers. The following question came to mind: What causes power washers to overheat? According to our knowledge, the following are possible causes:

  • When using hot water in a power washer that is designed to handle cold water.
  • The heating system may overheat if there is a mechanical issue with it.
  • Failure to supply the device with enough water. GPM standards dictate how much water should be pumped into a pressure washing equipment. Check the pump’s rating before following any instructions.
  • Overheating might lead to pump damage if you leave your power washer running for more than five minutes.
  • Overheating is a common concern with gasoline-powered pressure washers. The manufacturer’s fuel pressure requirements should be checked before starting the machine.
  • Properly placed burner nozzle and incorrectly configured unloader are two more causes of overheating in pressure washers,
  • Pressure washers’ thermostats can malfunction, resulting in hitherto unheard of levels of overheating.

Diagnosing pressure washers for overheating

In by-pass mode, your power washer should emit a sweltering heat. Pump pressure spikes and extremely hot water are two telltale indications of overheated equipment. Therefore, we recommend that you cease using the machine and contact a repair expert. If a power washer’s heating problem persists, you should not risk operating the machine. You should also avoid attempting to resolve the problem yourself, especially if you have no idea where to begin. Overheating power washers can be dangerous, so we discourage guesswork when it comes to fixing the issue.

Role of a thermostat in regulating pressure washer temperature

In most machineries, the thermostat is a critical component. To keep the temperature in the room at a comfortable level, this is a thermostatic fitting. As a result, learning how your power washer’s thermostat works will be helpful when attempting to resolve the overheating issue.

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There are two types of pressure washer thermostats: those that can be adjusted and those that cannot be adjusted. The temperature of the water will, of course, rise above the ideal level. When the heater doesn’t go out, you can rule out or confirm a malfunction by diagnosing the thermostat. By cycling the burner nozzle on and off, fixed thermostats maintain the desired water temperature. As a result, in order for the thermostat to function properly, you must set it to the desired temperature. It’s normal for the water’s temperature to fluctuate. However, in order to maintain a steady water temperature, lower the heat output of the burner nozzle.

Pressure washers without a thermostat, on the other hand, create a unique set of problems. When utilizing the machine, the water temperature should rise steadily due to the regular firing of the burner nozzle. Make use of a safety switch in order to prevent overheating. The safety switch turns off as soon as the water reaches the predetermined temperature.

Do electric pressure washers overheat?

These machines overheat easily. It’s possible for a variety of reasons. In electric pressure washers, overheating can occur if the device is left running when it is not in use. Pumps are frequently damaged as a result. A problem with the power supply circuit might also result in an electric pressure washer overheating. Electric power washers can overheat, resulting in an electric shock if the capacitors or fuses fail, and this can be dangerous. Consult a professional service provider to discover the problem if you are unable to conduct a diagnostic.

Is it bad to leave a pressure washer running?

Yes, running a pressure washer for longer than five minutes is a terrible idea. Do not leave the machine inactive for more than five minutes if you are unable to turn it off after a few attempts. Leaving your pressure water running can cause harm to the pump’s internal workings, as the temperature rises.

With pressure washers, you’re stuck with a fixed GPM flow rate since you have to pull a trigger gun to get the water flowing. Because of the constant flow of air, the machine’s internal components stay at a comfortable 60 degrees Fahrenheit. However, if you pull the trigger while the engine is still running, the water will cease flowing. Recirculation occurs in the pump, often at high pressure, while the pump exit is omitted. Water continues to heat up when it is recirculated.

Assume that the water in the pump’s head reaches a temperature of 145 degrees Fahrenheit. If the water in your power washer continues to heat up, it could damage the machine. The worst happens if you don’t turn off the system within five minutes. Pressure washer pumps suffer damage from overheating caused by water recirculation. As a result, the last thing you should consider doing is leaving pressure washers running. Shut down your power washer if something stops your cleaning process. Nevertheless, if the interruption is less than three minutes long, use the trigger pistol to open the freshwater supply. Within a few minutes, the pump should begin to cool down.

Pumps in pressure washers are immediately damaged by overheating. It’s also possible that other issues, such as:

  • O-rings: O-rings break down more quickly.
  • Additionally, the pump and other components’ water seals will need to be replaced much sooner than originally anticipated.
  • Due of the low pressure on the sides, some components may warp.
  • In addition, valves will be deformed.

Protecting pressure washers from thermal damage

Pressure washer repair and maintenance costs will more than double if thermal damage occurs. Because of this, you should avoid it at all times. We recommend installing a thermal valve in addition to not letting the machine sit idle in by-pass/running mode for longer than five minutes.

When the pump reaches 145 degrees Fahrenheit, a thermal valve will open. The hot water exits the valve when it is opened. The cooling system is then replenished with cool, fresh water. Whenever you open the thermal valve, make sure it returns to its original position correctly. No need to worry if your power washer uses a stainless steel plunger. In order to prevent overheating, the ceramic coating on the steel plungers is used.

What Causes Cavitation In A Pressure Washer Pump?

When the volume of water being provided to a pressure washer pump per hour is less than the amount required for the pump to operate effectively, cavitation might occur. In order for a pressure washer pump to function correctly, it requires a certain amount of water. In most cases, you may find this information in the instruction booklet that comes with the pressure washer.

The first step is to determine how much water the pressure washer pump needs and how much water is being supplied to it.

Use a 5-gallon bucket and a timer to see how long it takes to fill the bucket to determine the quality of your water supply. If it takes a minute to fill a 5-gallon bucket, the rate of filling is 5 gallons per minute (5 GPM).

The water supply to the pressure washer may need to be increased if it is running low. For instance, cavitation is likely to occur if the pressure washer pump only receives 2.9 gallons per minute, instead of the required 3 gallons per minute.

A larger diameter garden hose, such as a 3/4-inch hose, might be used to supply the pressure washer, increasing the GPM. Use a 25-foot hose instead of the standard 50-foot length instead of the 100-foot version. This may also help. The GPM of the pressure washer can be increased by either of these approaches.

To avoid kinking, make sure your garden hose is heavy enough. If your pressure washer’s hose is kinked, you’ll lose all of your water supply and your machine will likely be damaged in the process.

What Causes Overheating Of A Pressure Washer Pump?

Pumps overheat because they’ve been in bypass mode for too long. During bypass, the pressure washer pump is in a state where the trigger has not been depressed or pushed in.

The pressure washer pump overheats when left on when not in use, to put it simply. Leaving the machine in bypass mode for more than a few minutes is generally discouraged by the vast majority of makers.

However, the pressure washer pump gets extremely hot after just a minute in bypass mode and can cause damage if you use it again. If you plan to leave the machine in the bypass mode for more than 45 seconds, you should switch it off.

Even if you’re only going to be gone for a few minutes, always switch off the machine before you leave. In the time you’re away from the pressure washer pump, you never know what might pique your interest

The pistons could shatter if the machine is in bypass for too long if the trigger is depressed, as cold water from the water supply will reach the heated pistons. The pressure washer pump will be destroyed if the machine overheats, and the pressure washer as a whole and you will be seriously damaged.

When the pressure washer is left in the bypass mode, the temperature can rise to over 100 degrees Fahrenheit. This puts the user at danger of serious injury or death from burns caused by the extremely high temperatures.

Make sure the pressure washer is turned off when not in use to prevent injury to you and anyone around you.

How Does The Unloader Valve Effect The Pressure Washer Pump?

When the pressure washer is not in use, the unloader valve allows water to bypass the pump and return to it. In a nutshell, the unloader valve is responsible for regulating the flow of water.

It is possible that the unloader valve in some pressure washers acts as a pressure regulator, so long as it is set correctly, ensuring that the pressure is maintained.

While working with an unloader valve, it is important to read the instructions and make sure the valve is set correctly for your specific pressure washer before you start using it.

The pressure washer pump and the pressure washer itself might be severely damaged if the unloader valve is placed incorrectly. The pump’s lifespan will be shortened if it can no longer perform its intended job as a result of being overloaded.

Make certain all of your pressure washer pump’s settings are proper to prolong the life of the pump. To achieve this, refer to your unloader valve’s handbook for instructions on how to modify it.

What Are Some Things You Can Do To Make A Pressure Washer Pump Last Longer?

When shopping for a pressure washer, do your homework to ensure that the pump lasts as long as possible.

  • Learn about the pressure washer’s various components.
  • When the machine is not in use, turn it off.
  • When the machine is in use, ensure that the correct water supply is in place.
  • Make effective use of the unloading valve.

When looking for a pressure washer pump, it’s important to know how long the pump is expected to last. If the lifespan isn’t specified, it’s safe to assume the seller doesn’t want you to know and you should proceed with caution. Generally speaking, the more expensive the pressure washer, the greater the pump’s quality.

Learn how to properly use the unloader valve and how to prevent pump overheating. Make sure you know how to check for overheating and cavitation as well. To minimize cavitation, ensure sure the water supply is greater than the amount needed for the pressure washer before using it with any new water source. Using these tips, you can get the most out of your pressure washer pump without causing any harm.

Shut Down The Pressure Washer

Don’t waste money on pressure washer repairs because of negligence. Make sure you don’t take any calls while cleaning. As a result, you should avoid using it in a time-saving manner. It’s best to turn off the pressure washer than to risk damaging the pump. Pressure washers use liters of water for every unit of power. The water supply is sufficient to supply the unit. For a unit with a pump rating of 5 gallons per minute, the water supply should be at least 5.0 GMP. The cavitation caused by anything more small prevents the gun from generating a pressure surge. There is a chance of long-term injury even under the most extreme settings. This machine can’t function properly without a reliable water supply. Pressure washers can overheat if they don’t have enough water flow.

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How Long You Can Run A Pressure Washer: Overheating

Pressure washers have a tendency to overheat. That begs the question of how a pressure washer might induce it. The following are the primary causes:

#1. Gas problems

A gasoline-powered pressure washer might overheat if the fuel pressure is too high. Before starting the washer, check the manufacturer’s instructions for fuel pressure.

#2. Time

In other words, for how long does a pressure washer last? Overheating can occur if the pressure washer is allowed to run for more than five minutes at a time. It’s a common cause of pressure washer pump failure.

#3. Thermostat

An overheating problem might be caused by a thermostat in the pressure washer.

#4. Wrong use

Additionally, poor burner nozzle installation might lead to overheating. Afterwards, check to see if the unloader isn’t set to the correct position.

#5. Hot water

In a pressure washer, hot water might cause problems if it is utilized with cold water.

#6. Mechanical problem

Because of significant heat buildup, this issue may arise.

#7. Failure in pumping an adequate amount of water

Follow the GPM specifications and add a significant volume of water to the pressure washer. Check the pump’s rating to see where it’s pointing you.

Diagnosis Of Overheating In Pressure Washer

When the pressure washer is on by-pass, you can feel the heat. Pump pressure spikes and boiling water are two telltale signs of an overheating system. To get professional repair support, turn off the unit and seek assistance from the manufacturer. A pressure washer’s heating difficulties are mechanical. Don’t try to utilize the system again if the issue remains. Furthermore, if you’re not sure how to remedy the problem, don’t do it. The overheated pressure washer can’t be fixed by guessing. This is a list of the seven reasons why your pressure washer is overheating.

Thermostat Role In Regulating The Temperature

A pressure washer’s thermostat is the most important part. Using this component, the temperature can be adjusted to be either above or below the ideal level. A pressure washer’s thermostat can be used to diagnose an overheating machine. Adjustable and non-adjustable thermostats are both available. Over time, the temperature of water naturally rises over the ideal level. The thermostat should be checked if there is any heat in the room.

As the nozzle is turned on and off, a set thermostat maintains the proper water temperature. To get the most out of your pressure washer, make sure the thermostat is set to the correct temperature. Don’t get too hung up on the fact that water’s temperature rises and falls. Adjust a burner nozzle’s heat output to reduce its output.

However, a pressure washer with a non-adjustable thermostat has a different issue. Because the burner nozzle is always firing, the water’s temperature rises steadily. Use a safety switch to prevent overheating in this situation. As soon as the desired water temperature is reached, the safety switch is automatically deactivated.

Final Thoughts

If you keep a pressure washer running for any length of time, it will eventually overheat. As a result of the pump head’s design, water recirculation occurs when the trigger is released. Overheating is a common cause of pressure washer damage, therefore you run the danger of ruining your most useful cleaning tool. Perform not leave a power washer on bypass mode if you intend to do something in the middle of a cleaning process.

If you’re a first-time power washer user, we recommend that you read the instructions before you buy or use the machine for the first time. Avoid overheating the pump by pumping 5 gallons of water per minute if the RPM is set to 5.0. In low-pressure areas, the reduced flow of water can cause warping due to component overheating.

Helen Skeates

Helen Skeates

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