No reliable answer
Documented sources for this exact unit could not be found or did not support an answer. That is the honest result — nothing below is guessed.
What was searched
- Aquarest ZX-9000 Pro manual
- Aquarest ZX-9000 spa
- Aquarest spa ZX-9000 Pro not heating error codes
- "ZX-9000" Aquarest
- "ZX-9000 Pro" hot tub
- AquaRest spa model list / lineup (Select, Elite, AR- series)
- aquarestspas.com owners manuals model lineup AR-300 AR-500 Day Dream
What was found
- Official AquaRest owner's manuals exist for the UHS and HU2 spa control platforms (PN 378100 series) hosted on aquarestspas.com, but none reference a ZX-9000 or ZX series.
- The manufacturer's own owners/support and showroom pages list AquaRest's product lineup under names such as AR-300, AR-400, AR-500, AR-600, Select 300, Elite 500/600, and Day Dream — no ZX-prefixed model appears.
- ManualsLib's AquaRest Spas brand page indexes owner's manuals only for AR-300 TRI, AR-400 X4H, AR-500 X5H, and AR-600 EZB.
- Retailer listings (Home Depot, Wayfair, Amazon, AquaRest Outlet) for AquaRest spas likewise show only AR-/Select/Elite naming.
- Every search for the literal string "ZX-9000" returned unrelated products (Adidas ZX 9000 sneakers, Master Spas LSX 900, Pinnacle Spas LX 9000) — no hot tub by AquaRest with this designation.
- General AquaRest 'not heating' troubleshooting content exists on third-party Q&A and blog sites (JustAnswer, tpa10.com, troubleshootinglab.com), but none is tied to a ZX-9000 Pro or any documented family containing it.
Why it is not enough
No manufacturer, dealer, or retailer source found in this session documents an AquaRest 'ZX-9000 Pro', and the designation does not fit AquaRest's documented model naming (AR-###, Select, Elite, Day Dream) or its documented control-pack families (UHS, HU2). Because the model cannot be matched to any documented family, there is no source-backed error-code table, documented cause list, or documented action for a 'not heating' symptom on this unit. Applying generic hot-tub or generic AquaRest troubleshooting here would be a guess, not documentation. Next step for the owner: re-read the data plate (the plate on AquaRest spas typically shows a model code such as X5H-UHS-BB or AR-500, plus the control pack designation) and photograph it, including the topside control panel and any code currently displayed; with that exact model/pack code the correct manual and error-code table can be identified.