How Do I Use the Siphon Hose if My Pressure Washer Didn’t Come With a Detergent Tank?

This article provides instructions for using and maintaining the detergent siphon system on Generac pressure washers without an integrated detergent tank, including setup, flushing, and after-use care steps.

Aug 1, 2025
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How Do I Use the Siphon Hose if My Pressure Washer Didn’t Come With a Detergent Tank?

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How-Do-I-Use-the-Siphon-Hose-if-My-Pressure-Washer-Didn-t-Come-With-a-Detergent-Tank

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Using the pressure washer siphon hose

Generac pressure washers without an integrated detergent tank require the use of a siphon hose and an external detergent bucket to apply detergent. This article walks through the process of setting up the pressure washer to use the siphon hose, how to flush the system, and recommendations for storage.

Environment

This article applies to Generac pressure washers without an integrated detergent tank.

Does my pressure washer have a detergent tank?

Most pressure washers will include an integrated detergent tank, however; several commercial and prosumer models do not. (see below for an example of each)
For pressure washers without included detergent tanks, the pressure washer utilizes a siphon hose to siphon soap or detergent from a separate bucket or container to the pressure washer's pump.

Commercial/Prosumer model (no detergent tank) Model with detergent tank

To locate the owner's manual for your pressure washer and determine the detergent tank type, see How Do I Find the Spec Sheet and User Manual for My Pressure Washer on Generac.com?

How to use the siphon hose

1. Confirm that either the black detergent nozzle OR the red detergent nozzle is installed (see images below). If the correct nozzle is installed, proceed to step 4. If not proceed to step 2.

2. Pull back on the quick connect collar to install either the black detergent nozzle OR the red detergent nozzle. Release quick connect collar to secure nozzle. Verify nozzle is securely locked in place.

Note: Only use correct low-pressure nozzle when applying detergent.

3. Prepare the detergent solution in a container/bucket as required. Follow the manufacturer's recommendations on dilution ratios.

4. Insert filter end of the siphon tube into the detergent container/bucket.

5. Attach other end of siphon tube to detergent injector port on pump (A).

Note: the injector port is a brass fitting located next to the high-pressure hose connection port.

6. Start the pressure washer. Verify siphon tube stays submerged in detergent while in use. Be sure to route siphon tube away from the muffler to prevent damage.

7. Apply detergent starting at lower portion of area and work upward using long, even, overlapping strokes.

8. Flush siphon system after each use before stopping engine. (see instructions below)

Note: Do not use caustic liquid, such as bleach, with the power washer. Use only power washer safe detergents.

How to flush the siphon system

1. Place detergent siphoning tube/filter in bucket of clean water.

2. With the black detergent nozzle installed, flush the system for 1–2 minutes.

3. Shut engine OFF.

4. Point spray gun in a safe direction, squeeze spray gun trigger to release retained high water pressure. Engage trigger lock.

After each use

1. DO NOT allow water to remain in unit for long periods of time. Sediments or minerals can deposit on pump parts and freeze pump. Follow these procedures after every use:

2. Shut engine OFF.

3. Turn water supply OFF.

4. Let engine cool.

5. Disconnect hoses from spray gun and high-pressure outlet on panel. Drain water from hoses, spray gun, and lance. Use a rag to wipe off components.

6. Verify engine start switch and fuel valve is OFF.

7. Pull recoil handle approximately six times to remove remaining liquid from pump.

8. Store unit in a clean, dry area.

Note: If storing for more than 30 days, see the Storage in the pressure washer owner's manual: How Do I Find the Spec Sheet and User Manual for My Pressure Washer on Generac.com?

Troubleshooting

If experiencing issues with the siphon hose suctioning, confirm the following:

Detergent siphoning tube is fully submerged in the container/bucket.
Detergent siphoning tube or filter is not obstructed or cracked. Clean or replace tube/filter if necessary.
Correct nozzle is installed.

How Do I Use the Siphon Hose if My Pressure Washer Didn’t Come With a Detergent Tank?

Using the pressure washer siphon hose

Environment