Hayward Heat Exchanger Assembly-H350FD | FDXLHXA1350
Hayward Products
SKU: FDXLHXA1350
Hayward FDXLHXA1350 Heat Exchanger Assembly for Universal H-Series Low NOx H350FD Heaters
The Hayward FDXLHXA1350 is a genuine OEM heat exchanger assembly designed for the Hayward Universal H-Series Low NOx pool heater model H350FD. This is the primary water-to-flame heat transfer component inside the heater. It’s typically replaced when the existing exchanger is leaking, restricted by scale/debris, or damaged from freeze events, corrosive water chemistry, or long-term wear.
Fits / Compatibility
- Hayward Universal H-Series Low NOx heater model: H350FD
- Plumbing connection style commonly listed as 2" x 2-1/2" CPVC union connections (heater-side union/header interface)
- Designed as a direct OEM replacement where FDXLHXA1350 is specified on the parts diagram
Common Reasons to Replace the Heat Exchanger
- Water leaking from inside the heater cabinet (especially during circulation or heating)
- Reduced heater performance due to scale buildup or internal restriction
- Exchanger damage from freeze conditions
- Corrosion or pitting from aggressive water chemistry or improper balance
What’s Included
- (1) Complete heat exchanger assembly (FDXLHXA1350)
Specs (Quick Reference)
- Part Number: FDXLHXA1350
- Application: Heat Exchanger Assembly
- Heater Model: H350FD (Universal H-Series Low NOx)
- UPC: 610377073745
- Approx. Weight (typical listing): 48.5 lb
Installation Notes
- Qualified service recommended: replacing a heat exchanger typically involves gas heater service and internal disassembly.
- Shut off power and gas to the heater, relieve system pressure, and allow the unit to cool before service.
- If the original exchanger failed due to scale or low flow, correct the root cause (water balance, bypass, filter condition, pump flow) to prevent repeat failure.
- Inspect/replace any disturbed O-rings, gaskets, and unions during reassembly to ensure a leak-free seal.
Related Products
- Hayward FDXLHXA1350 (search)
- Hayward H350FD Heater Parts (search)
- Hayward FD Heater Water Pressure Switch (FDXLWPS1930) (search)
- Hayward FD Heater Thermistor (FDXLTER1931) (search)
- Hayward FD Return Manifold / Header Kit (FDXLPRM1930) (search)
- Hayward FD Heater Union O-Rings & Seals (search)
Maintenance Tips
- Maintain balanced water chemistry (especially pH, alkalinity, and calcium hardness) to reduce scaling and corrosion inside the exchanger.
- Keep filters and pump baskets clean—low flow can overheat the heater and stress internal components.
- If the heater is installed in a freeze-prone area, properly winterize and drain the unit to prevent exchanger cracking.
- Address small leaks early—mineral buildup can damage sealing surfaces and lead to larger failures.
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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