Hayward Bypass Valve Kit | HAXBPK1931
Hayward Products
SKU: HAXBPK1931
Hayward HAXBPK1931 Bypass Kit (Old Style Header) — H-Series / ED1 (Pre-10/28/2000)
The Hayward HAXBPK1931 is an OEM heater bypass kit designed for Hayward H-Series gas pool heaters that use the old style header. The bypass assembly helps regulate internal water flow through the heater’s heat exchanger, supporting stable operation and helping protect the exchanger under varying flow conditions.
Fits / Compatibility
- Hayward H-Series Millivolt & Electronic Ignition (ED1 style) heaters made before 10/28/2000
- Common compatible ED1 models include: H1501, H2001, H2501 (verify heater data plate)
- Also commonly referenced for select H-Series Induced Draft heater applications that use the old style header
Fit tip: Hayward has different bypass kits depending on heater generation/header style. Confirm your heater manufacture date and header style before ordering (this kit is for the older style configuration).
What’s Included
- Black plastic bypass baffle
- Round bypass end (brass)
- Bypass shaft and plug (brass)
- Bypass spring
- Header O-ring (commonly referenced as HAXHOR1930)
Common Reasons to Replace
- Heater header service where the bypass parts are worn, damaged, or missing
- Recurring header leaks traced to a flattened or damaged header O-ring
- Flow-related heater issues where inspection shows a stuck or deteriorated bypass assembly
- Preventive rebuild on older H-Series heaters to restore proper internal flow control
Specs (Quick Reference)
- Part Number: HAXBPK1931
- Part Type: Heater Bypass Kit (Old Style Header)
- Pool Type: In-Ground
- Approx. Shipping Weight: 14.4 lb
Installation Notes
- Turn off power to the heater and pump, and allow the heater to cool before servicing.
- Relieve system pressure before opening the header/union area.
- Clean header sealing surfaces and O-ring grooves before installing new components.
- Use a light coat of silicone-based lubricant on O-rings only (never petroleum-based).
- If the header is cracked/warped or sealing surfaces are damaged, replacing the bypass kit alone may not stop leaks.
Related Products
- Hayward HAXBPK1931 Bypass Kit (search)
- Hayward HAXHOR1930 Header O-Ring (search)
- Hayward HAXNNO1930 Heater Union/Nipple Kit (search)
- Hayward HAXPSA1930 Water Pressure Switch Assembly (search)
- Hayward H-Series Heater Parts (search)
- Silicone O-Ring & Gasket Lubricant (search)
Maintenance Tips
- Keep filter pressure under control—dirty filters and restricted flow can cause heater issues that look like bypass problems.
- Maintain balanced water chemistry to reduce scale in the heat exchanger and header area.
- After any header service, run the system and check carefully for slow drips; small leaks can quickly leave mineral deposits and worsen sealing.
- Support nearby plumbing so the heater header/unions aren’t under constant stress from misaligned pipes.
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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