You’re ready to tackle that grimy driveway or moss-covered deck, but a nagging question holds you back: Will a power washer work with low water pressure? The short answer is: it’s complicated. While most electric and gas pressure washers are designed to amplify the pressure from your existing water supply, they do have minimum requirements. This definitive guide will clear the confusion and help you get the job done, even with less-than-ideal water flow.
Understanding Pressure Washer Basics: Flow vs. Pressure
To answer our core question, you must first understand two key metrics: Gallons Per Minute (GPM) and Pounds Per Square Inch (PSI). GPM is the flow rate, or volume of water. PSI is the force of that water. A pressure washer’s pump needs a sufficient volume of water (GPM) to create its high pressure (PSI). If your home’s water supply has low flow, the pump can “starve,” leading to pulsation, overheating, and potential damage.
Minimum Water Supply Requirements
Most residential pressure washers require a minimum inlet flow of 3-5 GPM at 20-40 PSI to operate correctly. You can test your home’s flow rate with a simple bucket test. If your supply falls below the machine’s requirement, performance will suffer drastically.
Solutions for Using a Pressure Washer with Low Flow
Don’t despair if you have low water pressure! You have several effective options:
1. Use a Dedicated Water Tank: Bypass your home’s supply entirely. Connect your pressure washer to a large static water tank (e.g., a 50-gallon drum). A transfer pump can help feed water from the tank to the pressure washer consistently.
2. Install a Booster Pump: For a permanent solution, a water booster pump installed on your main line can increase both pressure and flow to your entire outdoor spigot system.
3. Optimize Your Setup: Use shorter, wider inlet hoses (3/4-inch diameter). Ensure all connections are tight and filters are clean to minimize restrictions. Always run the machine from the cold water line.
Choosing the Right Nozzle Tip
When flow is limited, nozzle selection is critical. Avoid the aggressive zero-degree (red) tip. Opt for a wider 40-degree (white) or soap nozzle. This spreads the available water over a broader area, reducing the demand for immediate volume and helping to prevent pump cavitation.
FAQ: Your Low Water Pressure Questions Answered
Q: Can I just use a pressure washer on a well system?
A: Yes, but wells often have lower flow. Ensure your well pump’s output GPM exceeds your pressure washer’s inlet requirement. A holding tank is highly recommended.
Q: What happens if I use it with insufficient pressure?
A> You risk pump cavitation—where the pump runs partially empty, creating damaging vibrations and air bubbles. This can destroy the pump seals and internal components quickly.
Q: Are some pressure washers better for low pressure?
A> Units with axial cam pumps are generally more sensitive. Professional-grade machines
