# TLDR Review: A.O. Smith ProMax Plus 40 Gallon

*Published: 2026-03-02 | Updated: 2026-03-02 | Source: https://shopsavvy.com/reviews-tldr/a.o.-smith-promax-plus-40-gallon*

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## Product: A.O. Smith ProMax Plus 40 Gallon
**Brand:** AO Smith

## Pros
- Heats water almost immediately on demand
- Runs for brief periods only when hot water is drawn, improving efficiency
- Notable improvement over older heating systems
- Provides good value
- Outstanding quality compared to other units

## Bottom Line

If you've got propane access and you're tired of waiting around for hot water, this A.O. Smith unit is basically the overachiever of water heaters—reviewers consistently praise its snappy performance and rock-solid reliability. At $753.29, we think you're getting solid value here, especially if you're upgrading from an older system. The real talk? This isn't a con exactly, but you'll definitely need a propane supply lined up, so make sure that's already part of your setup before you commit. Bottom line: if propane works for your situation, you've got yourself a dependable hot water solution that'll serve you well.

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*About this review: We pulled together findings from professional and user reviews, and cross-referenced them with ShopSavvy's pricing data from thousands of retailers to give you the short version.*