Where to Find Your Pool Heater's Owner's Manual by Brand (2026)

Quick answer

Your pool heater’s model number is on a rating plate riveted inside the cabinet — behind the front door on most gas heaters, or on the electrical cover’s dataplate for a Hayward HeatPro — never printed on the outside. Once you have it, Pentair and Jandy/Zodiac host direct model-specific manual PDFs you can usually find by searching the exact model name, Hayward requires its own SKU-search tool with your exact model number, Raypak organizes manuals by product series in a browsable document archive, and AquaCal covers current models well but sends older units toward third-party libraries. Getting the model number right matters beyond troubleshooting, too — it’s also what a manufacturer checks against warranty terms that can vary by suffix or purchase channel.

Step one: find your exact model number, not the serial number

Every manual search starts in the same place — a metal rating plate riveted to the inside of the heater, listing model number, serial number, and BTU or electrical rating together. On most gas heaters from Raypak, Pentair, and Hayward, that plate sits just inside the front access door; on Raypak units it can also be on the right side exterior panel depending on the model. Hayward’s HeatPro heat pumps break that pattern — their dataplate is mounted at the bottom right of the electrical cover instead of behind a front door, since there’s no combustion chamber to access. The easy mistake here is grabbing the serial number instead of the model number — they sit next to each other on the same plate, but only the model number will match you to the correct manual, parts list, or warranty term.

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Not every brand organizes its manuals the same way

This is the honesty-hook worth knowing before you start searching: manufacturer manual libraries aren’t built the same way, and assuming one brand’s search habits will work on another wastes time. Pentair and Jandy/Zodiac are the easiest — both host manuals as direct, permanently-linked PDFs tied to a specific product line, so a search for the model name plus “manual” usually lands you on the right document in one try. Hayward is the opposite: its official Product Resource Search tool wants your exact SKU, not a family name like “H-Series” — a partial or generic search is more likely to return nothing useful than the general-purpose search on Jandy’s site would. Raypak sits in between, organizing its technical resources into a browsable document archive by product series rather than a single search box, which is more reliable than guessing a URL but slower than Pentair’s or Jandy’s direct-link approach. AquaCal is the honest outlier: its own site’s legacy manuals section covers current models reasonably well, but owners of older HeatWave or AeroTemp units are more likely to end up on a third-party library like ManualsLib than on aquacal.com itself — worth knowing going in, rather than assuming the manufacturer’s own site is always the fastest route.

What your Raypak model number already tells you

Raypak’s numbering is more literal than the other three brands, and it’s worth knowing even before you open a PDF. On the Digital gas-heater series, the leading digits in the model number are the unit’s BTU input in thousands — a 266A is rated at 266,000 BTU/hr, a 336A at roughly 332,000-336,000 BTU/hr, and a 406A at around 406,000 BTU/hr, the same numbering logic behind this site’s own “Digital 266K” shorthand for that exact unit. That’s enough to confirm you’re holding the right BTU tier for your pool size before you’ve even downloaded anything — see our sizing chart if you’re not sure what tier you need in the first place. The “A” suffix marks the current digital-ignition generation; a letter-free or differently-suffixed number usually signals an older or discontinued platform, and a model number that doesn’t fit this pattern at all is worth double-checking against Raypak’s own “How to Read a Raypak Model Number” page rather than guessing.

When the manufacturer’s site comes up empty

A model that’s been discontinued or superseded is the most common reason an official search turns up nothing — this site has documented that exact situation before, including Hayward quietly replacing the HP21404T heat pump with the newer, pricier HP21405T. Check whether the brand keeps a product-archive or discontinued-models section first; several do, even after pulling a unit from active sales pages. If that’s still empty, third-party manual libraries such as ManualsLib frequently host manuals a manufacturer has stopped hosting itself, particularly for older AquaCal and legacy Raypak units — useful, but not an official source, so treat any safety-critical number in it (gas supply pressure, minimum clearances, electrical requirements) as worth cross-checking against your electrical requirements or installation guide, or a current model in the same family, rather than taking it at face value.

The bottom line

Start inside the cabinet, not online — the rating plate there has the one string of characters every manual search actually depends on. From there, expect Pentair and Jandy to be a quick direct download, Hayward to require your exact SKU in its own search tool, Raypak to mean browsing a series archive (or decoding the BTU digits yourself), and AquaCal to be hit-or-miss enough on older units that a third-party library is a normal, if unofficial, fallback. And don’t file the manual away the moment you’re done troubleshooting — the same model number is what a manufacturer checks against warranty terms that, per our warranty guide, can shift by a purchase channel or a single digit in the suffix.

Sources: Raypak — How to Read a Raypak Model Number, Raypak Technical Resources — Pool & Spa Current Documents, Pentair — Homeowner Support, Hayward — Guide & Manuals, Hayward — Product Resource / Literature SKU Search, Jandy — JXi Gas-Fired Pool and Spa Heater, AquaCal — Legacy Heat Pump Manuals, H2OCO — Raypak Swimming Pool Heater Parts Breakdown, Models 206A/266A/336A/406A