Waterway 5/16" Snap-in Poly Jet Diffuser 218-4000
Waterway
SKU: 218-4000
Waterway 218-4000 5/16" Snap-In Poly Storm Jet Diffuser
The Waterway 218-4000 Poly Storm Jet Diffuser is a replacement snap-in diffuser used with compatible Waterway Poly Storm spa jets. This white diffuser installs into the back of the jet insert and helps secure the internal jet components while allowing proper water flow through the jet assembly.
This is the diffuser only, not a complete spa jet, jet face, wall fitting, jet body, or complete internal assembly. It is commonly replaced when the original diffuser tabs are worn, broken, brittle, or no longer holding the jet internal securely in place.
Product Features
- Genuine Waterway replacement jet diffuser
- Manufacturer part number: 218-4000
- 5/16" Poly Storm jet diffuser
- Snap-in style diffuser
- White plastic construction
- Designed for compatible Waterway Poly Storm jets
- Helps hold compatible jet internals in place
- Used for spa and hot tub jet repair applications
Product Details
| Brand | Waterway |
| Part Number | 218-4000 |
| Product Type | Jet Diffuser |
| Jet Series | Poly Storm |
| Style | Snap-In |
| Size | 5/16" |
| Color | White |
| Approximate Diameter | 2-3/16" where specified |
| Approximate Length | 3-1/2" to 3-9/16" where specified |
| Application | Replacement diffuser for compatible Waterway Poly Storm spa jets |
Compatibility
- Compatible Waterway Poly Storm snap-in spa jets
- Jet inserts using Waterway diffuser part number 218-4000
- Applications where the existing diffuser is marked 218-4000, 2184000, or a listed equivalent
- Not intended for Mini Storm, Power Storm, Cluster Storm, thread-in Poly Storm, or non-matching jet bodies unless the existing diffuser or parts diagram confirms 218-4000
Common Uses
- Replacing a broken Poly Storm jet diffuser
- Repairing jets that no longer stay snapped into place
- Replacing worn or brittle diffuser tabs
- Servicing compatible Waterway Poly Storm jet internals
- Restoring proper fit of the jet internal in the jet body
Installation Notes
- Turn off spa power and stop water flow before servicing jets.
- Remove the existing jet internal from the jet body.
- Inspect the old diffuser for broken tabs, cracking, brittleness, or chemical damage.
- Confirm the replacement diffuser matches the original part number and snap-in style.
- Snap the new diffuser into the compatible jet internal assembly.
- Reinstall the jet internal and confirm it locks securely into the jet body.
- If the diffuser or jet internals are brittle, flaking, or heavily worn, replacing the complete jet internal may be a better repair.
Related Products
- Waterway 210-6040 Adjustable Caged Style Poly Jet
- Waterway 210-6080 Adjustable Poly Jet Internal
- Waterway 210-6090 Roto Deluxe Poly Jet Internal, White
- Waterway 210-6097 Roto Deluxe Poly Jet Internal, Gray
- Waterway 218-1770 Poly Jet Wrench
- Waterway 210-3700 Poly Gunite Jet Assembly
Maintenance Tips
- Maintain proper spa water chemistry to reduce premature plastic deterioration.
- Inspect jet diffusers and retaining tabs during routine spa service.
- Replace diffusers that are cracked, brittle, chalky, or missing tabs.
- Clean debris from the jet body before reinstalling the jet internal.
- Check surrounding jet internals if multiple diffusers are failing or jets are repeatedly popping out.
Questions about returns? View our return policy.
Hours Of Operation:
Monday - Friday: 7:00 am to 5:00 pm Phoenix Time
Saturday: 8:00 am to 2:00 pm
Sunday: Closed
- We do not ship on Saturday or Sunday.
- Orders totaling more than $300 will require signature confirmation upon delivery.
- We process and prepare orders for shipment within 1 business day. Please note that many other pool supply retailers require 3–5 days of handling time before shipping.
- Orders placed after 1:00 pm Phoenix Time may not be eligible for same-day shipment.
- Expedited shipping options are available at checkout.
Return Policy:
- Products that are received damaged will receive a refund in store credit.
- Most products are eligible for return within 30 days of receipt, except where noted below.
- To initiate a return, please complete an RMA form prior to sending your item back.
- Original shipping costs are non-refundable and will be deducted from the return credit.
- Items returned missing accessories or original packaging, or that are not in the same condition as received, may be subject to a restocking fee of up to 100% depending on the condition of the item upon return.
- Some returns will be charged an automatic 15% restocking fee.
- We are unable to issue refunds for items that have been damaged or rendered inoperable due to installer error.
- Please complete the return form to receive your RMA number and return shipping label.
- Chemical products are not eligible for return under any circumstances.
- The Pentair Colorsync 618031 is not eligible for return.
- Pool cleaners are not eligible for return.
- Opened seals and o-rings are not eligible for return.
- Capacitors are not eligible for return.
- Plastic popup tools are not eligible for return.
- Automation components and circuit boards are not eligible for return.
- If a light is returned due to a reported malfunction and is found to be fully operational upon testing, return shipping costs and a restocking fee will be deducted from the refund.
- Orders refused at the time of delivery will be subject to the original shipping costs being deducted from the refund.
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