Pressure Washer Drain Cleaning: Steps, Tips, and Techniques

While pressure washing drain cleaning may seem like a powerful tool for clearing a clogged drain, it's generally not recommended. Pressure washers are designed for outdoor use and can generate extremely high water pressure, potentially damaging plumbing pipes if used incorrectly.

Using a pressure washer to unblock a drain can lead to even bigger problems, such as pipe bursts or leaks, and may require costly repairs. The high-pressure water jet can be powerful enough to cause cracks or leaks in older or fragile pipes. Different pipe materials have varying tolerance levels to pressure, with PVC pipes generally being more flexible and able to handle higher pressures than older clay or cast iron pipes.

Precautions During Pressure Washer Drain Cleaning

However, if you already own a pressure washer and want to attempt to clear a blocked drain, there are a few precautions to take:

1. Use a specialised drain cleaning kit designed for pressure washers, such as the Karcher PC20 pipe cleaning kit

2. Wear safety goggles and gloves to avoid any splashback

3. Slowly feed the drain cleaning tool into the drain for a few feet without applying pressure

4. Turn on the pressure washer and slowly feed the tool further into the drain, rocking it back and forth if you encounter an obstruction

5. Leave the pressure washer on as you withdraw the tool, turning it off before it fully comes out to avoid getting splattered

It's important to note that while this method can be effective for clearing some blockages, it should be used with caution and may not be suitable for all types of drains or pipe material. Suppose you're unsure about your pipes' condition or the block's severity. In that case, it's best to consult a professional plumber to safely and effectively clear the drain without causing further damage.

Pressure Washer Attachment for Drains

There are several options available:

Drain Cleaner Attachment

These are flexible hoses with a high-pressure nozzle that can be inserted into the drain. The powerful water jet helps dislodge and flush out debris and blockages.

Retrojet Nozzle

This type of nozzle has 4 rear-facing jets that spin at high speed to provide a more aggressive cleaning action inside the drain pipe.

Wiggly Nozzle

This nozzle's flexible, wiggly end allows it to better navigate bends and corners within the drain.

The key is to use the specialised drain cleaning attachments designed for pressure washers rather than just the standard pressure washer wand. The attachments ensure the high-pressure water is directed properly into the drain without damaging the pipes. The flexible hoses also allow access to deeper sections of the drain.

When using these attachments, it's still important to exercise caution and follow the manufacturer's instructions carefully to avoid any potential issues. Consulting a professional plumber is also advisable if you're unsure about the condition of your plumbing system.

Pro-Tip: Always choose specialised accessories made especially for drain cleaning when addressing a blocked drain with a power washer. Appliances such as a pipe cleaning kit can precisely guide your high-pressure water into the drain. This step ensures that you can avoid damage to your plumbing system. Do not use standard pressure washer wands because they are not intended for this use and can cause expensive repairs.

How can I safely use a pressure washer?

If you must use a pressure washer to clear a blocked drain, there are a few key safety precautions to take:

1. Use a specialised drain cleaning attachment for pressure washers, such as a flexible hose with a high-pressure nozzle. This attachment directs the water jet into the drain without damaging pipes.

2. Wear safety goggles and gloves to avoid splashback.

3. Slowly feed the pressure washer drain cleaning tool into the drain for a few feet without applying pressure first. Then turn on the pressure washer and slowly feed the tool further in, rocking it back and forth if you encounter an obstruction.

4. Leave the pressure washer on as you withdraw the tool, turning it off before it fully comes out to avoid getting splattered.

5. Never use the red 0-degree nozzle, as it generates extremely high pressure that can damage pipes.

6. Avoid using a pressure washer on older, fragile pipes like clay or cast iron, as the high pressure can cause cracks or leakSuppose

Suppose you're unsure about your pipes' condition or the block's severity. In that case, it's best to consult a professional plumber to safely clear the drain without causing further damage.

The key is to use the proper attachments and technique to direct the water pressure into the drain without spraying it at high pressure into the pipe walls. Caution is advised, as pressure washers can damage pipes if used incorrectly for pressure washer drain cleaning.

What safety gear should I wear when using a pressure washer?

When using a pressure washer, it's crucial to wear the proper personal protective equipment (PPE) to stay safe. Here are the key safety gear items to wear:

Safety Goggles or Face Shield

Pressure washers can cause serious eye injuries from debris and water spray. Wear impact-resistant, anti-fog goggles or a face shield that fully covers your eyes.

Rubber Boots

Rubber boots with good traction keep your feet dry and prevent slips on wet surfaces. Look for boots with metatarsal guards for added protection.

Heavy-Duty Rubber Gloves

Gloves should resist punctures and tears to protect your hands from high-pressure water, chemicals, and debris. They also provide a better grip on the pressure washer wand.

Waterproof Rain Jacket and Pants

A polyvinyl chloride (PVC) raincoat and pants will keep you dry and prevent flying debris from causing injury. Make sure they allow freedom of movement.

Ear Plugs or Muffs

Pressure washers can generate noise levels that can damage hearing. Wear earplugs or muffs to protect your hearing.

Avoid Loose Clothing

Wear fitted clothing to prevent it from getting caught in the pressure washer.

Pro-Tip: Wear the correct personal protective equipment (PPE) before beginning any pressure washing job. This covers waterproof clothes to keep you dry, safety goggles or a face shield to save your eyes from debris, and heavy-duty rubber gloves to protect your hands. To stop slips on damp surfaces, also wear rubber boots with strong traction. Wearing correct PPE guarantees a more comfortable working experience while improving your safety.

In addition to PPE, always read the pressure washer's manual, inspect the equipment before use, clear the work area of obstacles, and maintain a safe distance from the surface you're cleaning. Never aim the wand at people or animals. Following these safety precautions and wearing the proper protective gear will help prevent serious injuries when using a pressure washer.

What should I do if I need to make adjustments while the pressure washer is running?

If you need to make adjustments to your pressure washer while it is running, there are a few key things to keep in mind:

Never adjust the unloader valve to lower the pressure. 

Adjusting the unloader will reduce the flow rate (GPM) and decrease the overall pressure washing drain cleaning power, which is the product of pressure (PSI) and flow rate. The adjustment can lead to longer cleaning times and more wear on the machine.

Adjust the pressure by changing the nozzle size. 

A nozzle with a larger orifice will reduce the pressure, while a smaller nozzle will increase the pressure. Refer to a nozzle chart to find the right nozzle for the desired pressure and flow rate.

If you need to further reduce the pressure, try adjusting the engine throttle to lower the RPMs.

Adjusting the throttle will decrease the pressure output. However, be careful not to run the engine at too low of an RPM, which can damage the pump.

Wear proper personal protective equipment (PPE).

Safety goggles, gloves, and boots are some examples. Wear your protective gear before making adjustments to an active pressure washer. 

Test the adjusted pressure on a small, inconspicuous area first.

High-pressure water can be dangerous if not handled properly before cleaning the full surface. This method allows you to ensure you have the right pressure setting without risking damage to the surface.

The key is to avoid adjusting the unloader valve and instead focus on changing the nozzle size or engine throttle to safely lower the pressure output as needed. Taking these precautions will help you make adjustments without compromising the performance or safety of your pressure washer.