How to match a replacement pool part
Match a replacement to the brand, model, and serial on the equipment plate, then to the number on the old part, then to the pipe size. A photo is the last check. Pool pipe is commonly 1.5 inch or 2 inch, and those sizes are not interchangeable.
· Updated · 6 min read
Read the label on the equipment
Start at the equipment pad. The useful line is the brand, the model, and the serial number on the pump, filter, heater, or light transformer. Horsepower, voltage, and frame size are on that same plate. A “1.5 horsepower” pump still comes in more than one wet end, so the model is the number that matters.
Photograph the plate before you disconnect anything. Plates face the wall, and they are harder to read once the equipment is on a bench.
Read the number on the old part
Seals, impellers, lids, grids, and face rings are often stamped or labeled with their own part number. That number beats a description like “Hayward pump lid.” Search the store for the number as printed, including letters. If the stamp is partial, search the model from the equipment plate and compare the product’s manufacturer number on the page.
UPC barcodes identify the retail package. They are useful when the box is still around. They do not replace the manufacturer number molded into a fitting.
Measure the connection
Pool plumbing is commonly 1.5 inch or 2 inch, and the two are not interchangeable without an adapter that you meant to buy. Measure the outside of the pipe or read the size molded into the valve or union. Thread type matters too: a slip fitting, a threaded fitting, and a union are three different parts that can look alike in a thumbnail.
For a light, record voltage, cord length, and the niche brand. The checklist for a dead light is in a pool light is out. For a pump that runs without moving water, start with why a pool pump loses prime before you order a motor.
If two parts still look the same
Compare every specification on the product page with the plate and the old part. A shared housing can use different seals. A cartridge can share a diameter and differ in length. When the page does not list the specification you measured, do not assume it matches.
Send the photos of the plate and the old part through the contact form and include the measurements. We would rather confirm a part number than ship a near miss. A few parts need one extra label: heaters in how to read a rating plate, salt cells in how to match a salt cell, cartridges in how to match a filter cartridge, plus valves, skimmers, and drain covers.
Questions
What numbers do I need to match a pool part?
The brand, model, and serial on the equipment plate, plus horsepower and voltage if they are printed there. Then the part number stamped on the old seal, impeller, lid, grid, or face ring. Photograph the plate before you disconnect the equipment.
Does a 1.5 inch pool fitting fit a 2 inch line?
No. Pool plumbing is commonly 1.5 inch or 2 inch, and they are not interchangeable without an adapter you meant to buy. Slip, threaded, and union connections are different parts that can look alike in a thumbnail.
What if two pool parts still look the same?
Compare every specification on the product page with the plate and the old part. A shared housing can use different seals, and two cartridges can share a diameter and differ in length. If the page does not list what you measured, do not assume it matches.