Plastic vs Steel Spray Tower Dishwashers: What Lasts?

What is a spray tower?

A spray tower is a vertical column, usually located in the center or corner of the dishwasher tub, that rises toward the upper rack. It channels water to rotating spray nozzles so the top rack gets thorough cleaning. Some dishwashers use a single tall tower, others use a short tower with a spray arm on top. The material of that tower affects both cleaning performance and how long the part stays in good condition. For a deeper look at how towers differ from arms, see our spray tower vs spray arm comparison.

Spray towers are distinct from spray arms, which are horizontal bars that spin. A tower delivers water upward, while arms distribute water across a single level. Many dishwashers combine a tower for the upper rack with a lower spray arm. The choice between plastic and stainless steel for the tower matters because the component faces constant moisture, heat up to 140 degrees Fahrenheit, and detergent chemicals. The material also affects the longevity of the spray mechanism.

Plastic spray towers: common and capable

Most dishwashers on the market use plastic spray towers. Injection-molded polymers are inexpensive to produce, lightweight, and resistant to corrosion. Plastic also dampens the sound of water hitting the tower, which is one reason many quiet models rely on it. In normal use, a plastic tower can last the life of the dishwasher if it is not subjected to excessive heat or physical stress.

The main weaknesses of plastic appear over time. Hot water, especially in sanitize cycles that boost temperatures, can cause the plastic to warp or become brittle. Hard water minerals can cling to the spray nozzles and reduce water flow, making cleaning less effective. A cracked plastic tower may leak water pressure and cause uneven cleaning on the upper rack. Replacement is possible, but not always cost-effective on budget models. For tips on keeping the spray nozzles clear, see how to clean spray arm holes.

Stainless steel spray towers: built for longevity

Stainless steel spray towers are often found on higher-end dishwashers. The material resists corrosion, does not warp under high heat, and is less prone to mineral deposits than plastic. Steel towers also maintain their internal diameter better, so water pressure stays consistent even as the dishwasher ages. This can translate to more reliable cleaning on the top rack, especially for heavily soiled pots and pans.

Some manufacturers emphasize stainless steel construction as part of a premium build. For example, Fisher & Paykel, a brand known for luxury appliances, describes its products as "Built to Last" using quality materials and finishes. Bosch, another leading dishwasher brand, is rated as the quietest dishwasher brand in the U.S. and uses stainless steel interiors across many models, which often extends to the spray tower. These choices reflect a design focus on durability and long-term performance. If you're comparing interior materials, our stainless steel vs plastic tub guide explains similar trade-offs for the whole tub.

Which lasts longer?

Stainless steel clearly wins on durability. It does not degrade under the hot, wet, detergent-laden environment of a dishwasher. Plastic can last many years, but it is more susceptible to cracking, warping, and mineral clogging. If you keep a dishwasher for 10 years or more, a steel tower is more likely to still be functioning at peak performance at the end of that time.

That said, plastic spray towers are not a weak point on most modern dishwashers. Manufacturers use engineering polymers designed to handle the temperatures and chemicals they encounter. The practical difference in cleaning performance is small when both are new. The real advantage of steel shows up after years of use, particularly in homes with hard water or frequent hot-water cycles. For more on how spray arm materials affect cleaning, see spray arm material considerations.

Does material affect cleaning?

Cleaning performance depends more on water pressure, spray arm design, and cycle selection than on whether the tower is plastic or steel. ENERGY STAR notes that new certified dishwashers include innovations like soil sensors, improved water filtration, and more efficient jets. A well-designed plastic tower can deliver excellent cleaning, as evidenced by the many budget models that earn strong consumer ratings.

Where material matters is consistency. A steel tower does not flex under pressure, so the spray pattern remains stable. Plastic towers can absorb some energy, which reduces noise but might slightly reduce the force of the water. For most everyday loads, this is negligible. But if you regularly wash baked-on casseroles or dried-on food, the slightly stiffer water column from a steel tower might give your top rack an edge. To get the most out of any tower, proper loading matters; see our dishwasher loading guide.

Maintenance and replacement considerations

Both plastic and steel spray towers benefit from periodic cleaning. Food particles, grease, and mineral deposits can block the small holes in the nozzles. You can inspect the tower visually and use a toothpick or soft brush to clear clogs. Steel is easier to clean without worrying about scratching, but plastic is also safe with non-abrasive tools.

If a tower fails, replacement is possible. Plastic towers are generally less expensive and easier to find. Steel towers are sturdier but cost more to replace. Before buying, check whether the tower is a separate part or integrated with the pump assembly. Some dishwashers combine the tower with a fixed spray nozzle, making replacement a larger job. For troubleshooting, see our guide on how to replace a spray tower or how to adjust spray arm height.

What to pick for your use

Questions

Do all dishwashers have a spray tower?

No. Some designs use only spray arms, especially on countertop models. Full-size dishwashers often include a tower to reach the upper rack, but some use a dedicated upper spray arm instead. Check the spec sheet for 'spray tower' or 'spray arm coverage'. For a comparison, see spray towers vs spray arms.

Can I replace a plastic spray tower with a steel one?

Only if the manufacturer offers a compatible steel tower for your specific model. The mounting points and water flow paths differ, so you cannot simply swap materials. Check the parts diagram for your dishwasher. If you need to replace the tower, our spray tower replacement guide can help.

Does a stainless steel spray tower make a dishwasher louder?

Steel can transmit more noise than plastic, but manufacturers add insulation and sound pads to the tub to compensate. Many quiet dishwashers use steel towers and still achieve low decibel ratings. To compare noise levels, see our quiet dishwashers guide.

How do I know which material my dishwasher uses?

Look at the spec sheet on the manufacturer's website or check the user manual. If you have access to the unit, you can often see the tower through the bottom rack opening; it will be either glossy plastic or brushed metallic. For more on spray arm materials, see stainless steel vs plastic spray arms.