Quick Answer: “Smart tankless water heater” splits brands into two real categories, not one. Rheem’s entire current gas lineup (Performance Plus, Performance Platinum, IKONIC) and Navien’s current NPE-2 series build WiFi into the unit standard, at no extra cost, per each manufacturer’s own spec sheets. Rinnai’s Sensei RX series and Noritz’s EZ/EZTR series are only “WiFi-ready” — you have to buy a separate module (Rinnai’s RWM200, roughly $140-$165; Noritz’s NWC-ADAPTER, roughly $218-$239) to get the same remote app control. Check which category a listing falls into before assuming the WiFi feature you’re paying for is already in the box.
Retailers and even some manufacturer spec sheets use “smart,” “WiFi-enabled,” and “app-connected” almost interchangeably — but whether that means “it’s in the box” or “you’ll need to order a second part” depends entirely on the brand.
Built in vs. bolt on: what each brand actually ships
| Brand | WiFi included standard? | If not, what you buy | App |
|---|---|---|---|
| Rheem (Performance Plus / Platinum / IKONIC) | Yes — built in on every current gas model | Nothing extra | EcoNet |
| Navien (NPE-2 series, A2 & S2) | Yes — EZNav control panel, built in | Nothing extra | NaviLink / EZNav |
| Rinnai (Sensei RX series) | No — "WiFi Ready" only | RWM200 Wireless Wi-Fi Module, ~$139.99-$164.80 | Rinnai Central |
| Noritz (EZ / EZTR series) | No — adapter port only | NWC-ADAPTER, ~$218-$239 | Noritz Connect |
Our best Rheem tankless water heater guide already documents EcoNet WiFi and LeakGuard leak detection shipping standard across the IKONIC, Performance Platinum, and Performance Plus tiers — all three current gas models, not just the flagship. Our best Navien tankless water heater guide likewise lists the EZNav control panel with built-in WiFi on the NPE-240A2 and NPE-210A2 as a standard feature, not an upgrade.
Rinnai is the clearest example of the gap. Per Rinnai’s own current spec sheet, the Sensei RX199iN is “WiFi Ready,” and the fine print spells out what that means in practice: a separate module is required to control on-demand recirculation, remotely adjust temperature, or communicate with a service provider. That module — the RWM200 Wireless Wi-Fi Module, which replaced the discontinued RWM103 — runs about $139.99 at SupplyHouse and closer to $165 at some other plumbing suppliers.
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Noritz follows the same bolt-on pattern: its EZ and EZTR series tankless units ship with a WiFi-ready port, but the Noritz Connect app only works once the NWC-ADAPTER is installed — priced around $218-$239 depending on retailer, separate from the water heater itself.
Why this matters more than it sounds like it should
None of this changes how well any of these units heat water — GPM, UEF, and venting requirements are unrelated to whether WiFi ships standard. What it changes is the real out-the-door cost and whether “smart” is something you’re already paying for in the unit price or something you have to remember to add to the cart a second time. A buyer comparing a $1,199 Rheem Performance Platinum against a similarly priced Rinnai or Noritz unit on sticker price alone is missing that one of those two needs another $140-$240 part to do the same remote-control trick the Rheem already does out of the box.
It’s also worth separating “smart” from “better.” Rheem’s EcoNet bundle adds LeakGuard Plus leak detection on top of WiFi, which is a genuine extra feature, not just a pricing quirk — see our Rheem guide for how that stacks up against the competition on efficiency and price. Navien’s ComfortFlow recirculation, covered in our Navien guide, is a separate built-in feature from EZNav WiFi, not the same thing. Don’t let “has an app” become the only factor in a buying decision that should still start with GPM sizing and fuel type — our tankless water heater sizing guide covers that groundwork first.
The bottom line
If remote app control matters to you, check whether it’s actually included before comparing sticker prices. Rheem’s current gas lineup and Navien’s NPE-2 series build WiFi in at no extra cost; Rinnai’s Sensei RX and Noritz’s EZ/EZTR series are WiFi-ready but need a separate module — Rinnai’s RWM200 (roughly $140-$165) or Noritz’s NWC-ADAPTER (roughly $218-$239) — to get there. Once you’ve budgeted for that gap if it applies, our best tankless water heater guide covers the full buying decision beyond just the smart-home feature.