For a specific type of clog such as grease, sand or ice, professional plumbers know that nothing clears the clog faster than a water jet. High-pressure water jets have been the hottest tools among professional drain cleaners for the past few years. Now they're getting hot in the rental industry.

“I don't know what we did before water jets,” says George Bauer of Pittsburgh-based Bauer Plumbing. “They just blow everything away.”

When a drain-cleaning cable goes through grease, the grease will close up behind the cable and still leave the line clogged. A water jet flushes away sticky clogs like grease that cable machines have a hard time clearing. They use a stream of high-pressure water that hits the stoppage and flushes it away. The thrust of the nozzle drives the hose down the line, providing wall-to-wall cleaning action.

Jets do not replace cable machines, but each has specific advantages. Water jets are well suited to handle grease, sand and ice that are difficult obstructions for cable machines to clear, but they cannot clear heavy stoppages such as tree roots. In cold climates jets are often used to clear lines clogged with ice. The larger gas-powered water jets can clear a foot of ice per minute in a 4-inch line.

Jets are available in both electric- and gas-driven models. The most pressure a user can get from an electric jet without worrying about popping breakers is 1,500 psi at about 2 gallons per minute. This combination can handle most inside lines between 1½ to 4 inches and up to 150 feet long, but is not powerful enough to do a satisfactory job in main lines.

For outside lines up to 10 inches in diameter and up to 600 feet long, a gas-driven jet will provide the pressure and flow rate (3,000 psi at 4, 5½, 8 or 12 gallons per minute) required to do the job well.

A common question that rental operators should be prepared to answer is how to safely use a gas jet on an inside job. The answer is simple, but important to point out to all rental customers. Leave the gas jet outside and pull the jet hose into the basement or up onto the roof of the home. Then, hook the hose up to a portable reel with a smaller diameter hose to handle the inside lines. This keeps the exhaust safely outside while the high pressure of a gas jet is at work inside.

Jets vs. pressure washers

So, why shouldn't a rental company just use one of the pressure washers it already has in its rental fleet for drain cleaning? Here's why: Water jets have pulsation, which makes the hose vibrate to overcome the friction in the line so the hose will slide easily around bends and go longer distances. Without it, the hose is likely to get stuck. This is what separates water jets from pressure washers. When buying a jet, make sure it has a pulsation device.

In addition, a jet machine should have a backflow prevention device to keep sewer water from getting into the fresh water supply. Also, jet nozzles should be made of hardened stainless steel rather than brass because they will last longer and withstand the abuse of cast-iron pipe.

How to rent a water jet

Most rental customers don't know about water jets. Instead, they ask for what they know — a drain snake. If the snake doesn't clear the line, the customer gets frustrated, calls the plumber in to do the job, and the rental company loses that customer. Jets won't sell themselves; rental operators have to tell their customers that they've got something better for certain applications.

Rental companies can look at their current customer base to find rental opportunities for water jets. Restaurants, factories and institutions where grease clogs are a constant problem are just right for water jet applications. Rental businesses can start by contacting the restaurants in their area to tell them that they have the tool to prevent a clogged drain on a busy Saturday night when the waiting line is out the door. The rental salesperson may suggest to those business owners that they rent a water jet on a slow day every other month before a clog occurs. Hotels, schools and institutions are other natural customers for water jets.

Rental companies should make sure the plumbing professionals in the area know they've got water jets too. The younger plumbers may not yet have a water jet, and the established plumbing contractors often get busy enough that they'll need to rent an extra one.

Maintenance — The care and feeding of a water jet

Three key factors will cause a water jet to fail: 1) No water or not enough water 2) Hot water (above 160 degrees) or 3) Frozen water. Following the simple rules below will make using a water jet easy.

  • Rule 1. Make sure the water supply matches the needs of the jet

    If an operator is using a 4-gpm jet and the water source is only giving 2 gpm, there's trouble. An inadequate water supply will severely damage the pump. Make sure customers are using a good-quality ¾-inch water supply hose. Smaller hoses cannot carry enough water to meet the pump's needs.

    Tip: A good way to check the flow rate of a water source is to time how long it takes to fill up a 2-gallon bucket. If it takes 30 seconds or less, the flow rate is fine. If not, stop right there; the flow rate is inadequate.

  • Rule 2. Don't use hot water to clear grease-clogged lines

    Hot water will not only damage the pump, but it also won't clear the line properly. Hot water causes the grease to melt, but as the grease flows down the line it will cool and create a new clog someplace else. If cold water is used, it cuts the grease off the walls of the pipe in small chunks that easily flow down the line without creating new problems.

  • Rule 3. Don't leave a water jet out in the cold

    Rental operators should store jets indoors, or protect them with anti-freeze between uses to prevent freeze damage in cold climates.

Having the right drain-cleaning tool for the job, whether it's a snake or a water jet, will keep rental customers happy and coming back to rent again. And taking good care of the equipment will keep it making the rental operator lots of money.

Marty Silverman is marketing manager for McKees Rocks, Pa.-based General Pipe Cleaners.