Home Depot is the single biggest brick-and-mortar channel for tankless water heaters in the US, which makes it a reasonable place to start shopping — but “buy the cheapest listing” skips two things that matter more than the sticker price: whether that SKU is the retail or pro version of the hardware, and what happens if you need to return or service it after a plumber has already hooked it up. Here’s what’s actually on the shelf, what it costs, and the fine print worth reading before checkout.
What Home Depot actually stocks
| Brand | Home Depot availability | Notable line | Typical price range |
|---|---|---|---|
| Rheem | Deepest catalog — Home Depot is Rheem's primary retail partner | RETEX (electric) / ECO / ECOH / ECOHS (gas retail lines) | ~$519-$1,799 |
| Rinnai | Full residential lineup, indoor and outdoor | RE-series non-condensing, Sensei RX/RXP condensing | ~$1,280-$1,725+ |
| Navien | Dedicated brand page, condensing NPE line | NPE-A2/S2 series | ~$1,400-$1,900 |
| Bosch | Point-of-use Tronic series | Tronic 3000 US7/US9 | ~$180-$280 |
| EcoSmart | Whole-home electric ECO line | ECO 18/24/27 | ~$400-$650 |
| Camplux | Budget gas and outdoor units | WA686MG-NGN and similar | ~$250-$450 |
Prices per current Home Depot listings as of September 2026; retail pricing fluctuates with sale cycles, so confirm the current listing before assuming a figure above still holds.
By the numbers
- $1,280.79 vs. $1,391.40 list — the current Home Depot price on the Rinnai RE199iN, an 8% discount off list, with a further per-unit drop to $1,152.71 when buying 3 or more (a detail worth knowing if you’re outfitting a multi-unit rental property). — per Home Depot’s own product listing
- $2,400-$5,400 — the typical nationwide total for a professionally installed tankless water heater booked through Home Depot’s own installation service, which dispatches a licensed, background-checked local contractor rather than a Home Depot employee. — per Home Depot’s services pages
- 90 days, or 365 with a Home Depot credit account — the standard return window on an uninstalled unit; connect it to a gas, water, or electrical line and you’re on the manufacturer’s warranty instead, not Home Depot’s return counter. — per Home Depot’s published return policy
1. Rheem Performance Platinum ECOH200DVELN-3 — Best Home-Depot-Exclusive Retail Line
Rheem Performance Platinum ECOH200DVELN-3
- Sold under Home Depot's retail-specific ECOH naming — the same condensing platform a plumber would quote as the pro-channel RTGH, per our Rheem lineup guide's decoder for the brand's dual retail/pro catalog.
- At roughly $1,199, it undercuts Rheem's flagship IKONIC ECOHS200iN ($1,799 list, sometimes marked down as much as 20% during sale periods) by a wide margin for most of the same condensing efficiency.
- Home Depot's Pro Xtra or store credit card extends the standard 90-day return window to a full year on an uninstalled unit — worth applying for before a large appliance purchase if you don't already have the card.
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2. Rinnai RE199iN — Best Home Depot Discount on a Whole-Home Unit
Rinnai RE199iN
- Nearly flagship flow at a real discount off list — $110.61 less than the printed price, with volume pricing dropping further per unit at 3 or more.
- As a non-condensing unit it needs standard venting, not the PVC condensate setup a condensing model requires — see our venting guide before assuming your existing vent run works for either type.
- Home Depot's own installation service can quote and install this exact SKU, but get a second quote from an independent plumber first — the $2,400-$5,400 nationwide installed range leaves real room to shop the labor separately from the unit.
What a discounted Home Depot price doesn’t cover
A low sticker price is only part of the total cost. Two things trip people up after checkout:
- Retail vs. pro naming. Rheem in particular runs two parallel catalogs for the same hardware — retail SKUs at Home Depot (RETEX, ECO, ECOH, ECOHS) and pro SKUs through plumbing supply (RTEX, RTGH). A plumber quoting you an “RTGH” isn’t necessarily selling a different or better unit than the “ECOH” model on Home Depot’s shelf — confirm the actual platform, not just the name, before assuming one price beats the other.
- Installation is a separate line item. Home Depot’s own tankless water heater installation service dispatches a licensed local contractor and quotes the job independently of the unit price — it isn’t bundled into the shelf price the way it might feel at checkout. Get that quote (or an independent plumber’s) before comparing a Home Depot listing against a fully-installed price elsewhere, since the $2,400-$5,400 nationwide installed range can easily double the cost of the unit itself.
The bottom line
Home Depot is a legitimate, well-stocked channel for a tankless water heater — Rheem, Rinnai, Navien, Bosch, EcoSmart, and Camplux are all genuinely available, and the pricing on units like the Rinnai RE199iN or Rheem’s Performance Platinum line regularly beats list. The two things worth double-checking before you buy: whether the “retail” SKU on the shelf is the same hardware a plumber would quote you under a different name, and that the 90-day (or 365-day, with a Home Depot credit account) return window only protects a unit that hasn’t been connected yet — after that, you’re relying on the manufacturer’s warranty. Comparing against the other big box? Our Lowe’s tankless water heater guide covers a meaningfully shorter 48-hour defect window and a 20% restocking fee that Home Depot doesn’t charge, and our Menards tankless water heater guide covers a retailer that stocks three brand tiers at once but skips the in-house installer network entirely. Want the unit installed rather than bought off the shelf? Our Costco tankless water heater guide covers Costco’s single-brand Rheem installation program and its 12-year bundled warranty. For the full field of brands ranked side by side regardless of where you buy, see our best tankless water heater guide. Prefer to skip the aisle entirely? Our Walmart tankless water heater guide covers an online-only retailer that lists Rheem’s real RTEX pro-channel names rather than Home Depot’s retail-renamed RETEX/ECOH line.