Search for “Ferguson tankless water heater” and the brand you’re after determines how the shopping experience actually works. Our SupplyHouse.com guide already covers one plumbing wholesaler that sells to homeowners with fully open pricing and no Navien option at all. Ferguson is a different kind of mixed case: it’s one of the few channels that actually stocks Navien’s NPE-A2 line, but that specific brand’s listings come with a certification gate that the rest of Ferguson’s tankless catalog doesn’t share — and the company itself is mid-rebrand, folding its old Build.com consumer storefront into a single “Ferguson Home” identity.
What Ferguson actually stocks, and how access differs by brand
| Brand | Ferguson availability | Pricing access | Example price |
|---|---|---|---|
| A.O. Smith | ProLine XE and Adapt+ gas condensing lines | Open — no login | ATI-540H-N $1,092.32 |
| Eemax | HomeAdvantage II electric range | Open — no login | HA036240 $1,027.09 |
| Rheem | Pro-channel RTG/RTGH line | Open — no login | ~$1,200-$1,900+ |
| Navien | NPE-A2 series | Call for Pricing — certification required | Not publicly listed |
Prices per current and recently-confirmed Ferguson/Ferguson Home listings, checked October 2026; wholesaler pricing, stock status, and purchase gating change by brand and by location, so confirm the live listing before ordering.
By the numbers
- $1,092.32 — Ferguson’s price on the A.O. Smith ProLine XE ATI-540H-N, a 199,000 BTU condensing unit on the same core platform as the pricier Adapt+ ATHR-199X3, already confirmed in our A.O. Smith tankless water heater review. — per Ferguson’s own product listing
- $1,027.09 — Ferguson’s price on the Eemax HA036240, versus $866.61 for the identical SKU at SupplyHouse — a real retailer-to-retailer spread on the exact same model, per our Eemax tankless water heater review. — per Ferguson and SupplyHouse listings
- “Call for Pricing” — the label on Ferguson’s Navien NPE-A2 product listing, alongside a note that the item requires certification to purchase — a brand-specific access gate that neither A.O. Smith nor Eemax listings on the same site carry. — per Ferguson’s own Navien product page
- 2025 — the year Ferguson announced it was merging its Build.com consumer storefront and its Ferguson Bath, Kitchen & Lighting Gallery showrooms into a single “Ferguson Home” brand, with the Build.com domain kept live only temporarily during the transition. — per Ferguson’s own rebrand announcement
1. A.O. Smith ProLine XE ATI-540H-N — Best Open-Pricing Pick
A.O. Smith ProLine XE ATI-540H-N
- Same 199,000 BTU condensing platform as A.O. Smith's flagship Adapt+ ATHR-199X3, minus the X3 Scale Prevention Technology upgrade — see our hard water guide for whether that upgrade is worth the roughly $1,095 premium over this unit.
- No login or certification required to see this price — unlike Ferguson's own Navien listings, this one is fully open to any shopper.
- Ferguson's price undercuts SupplyHouse's Adapt+ price by roughly half, though the two units aren't an identical spec match — compare the X3 scale-prevention upgrade against your water hardness before assuming the cheaper unit is the better deal.
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2. Eemax HA036240 — Best Ferguson Pick for a Whole-Home Electric Install
Eemax HA036240
- SupplyHouse lists the identical model at $866.61 — a $160.48 gap on the exact same SKU, worth checking both wholesalers before ordering.
- A 36 kW draw needs a dedicated four-circuit electrical install — see our electrical requirements guide before budgeting the unit price alone.
- Eemax is Rheem's own sister brand under parent company Paloma Industries, per our Eemax tankless water heater review — not an unrelated budget import.
The Build.com-to-Ferguson Home rebrand, and what it means for buyers
If you’ve read an older tankless water heater review that cites a “Build.com” listing, that’s not a different retailer — it’s the same wholesaler catalog under its previous consumer-facing name. Ferguson announced in 2025 that it was merging Build.com and its Ferguson Bath, Kitchen & Lighting Gallery showrooms into one brand, Ferguson Home, with the Build.com domain staying live only temporarily during the transition. For a buyer today, that means the inventory, pricing, and account system are converging under FergusonHome.com rather than two separate storefronts — worth knowing if an older price citation or review still references Build.com by name, since it’s describing the same underlying business, not a defunct competitor.
What a Ferguson price doesn’t tell you
Wholesale access to A.O. Smith, Eemax, and Rheem at open pricing makes Ferguson worth comparing before you buy retail — but two things work differently than shopping SupplyHouse or a big-box store:
- Navien is gated, the rest of the catalog isn’t. Ferguson is one of the few channels that actually stocks Navien’s NPE-A2 line at all, a genuine advantage over SupplyHouse, which doesn’t carry Navien in any form. But that advantage comes with a catch: Navien listings show “Call for Pricing” and require certification to purchase, while A.O. Smith and Eemax listings on the exact same site are open to anyone. Don’t assume a certification requirement on one brand means the whole site works that way.
- The brand name on an older review may be stale. A “Build.com” citation in an older article or price comparison reflects a storefront that’s being folded into Ferguson Home, not a separate, still-independent retailer. Confirm current pricing on FergusonHome.com directly rather than searching for a Build.com-specific listing.
- No bundled installation. Like SupplyHouse, Ferguson sells the equipment only — there’s no Home Depot- or Costco-style bundled installation service. Budget a separate licensed-plumber quote.
The bottom line
Ferguson earns a real spot alongside SupplyHouse as a second plumbing-wholesaler option — and it’s the rare channel that actually stocks Navien, which SupplyHouse doesn’t carry at all. But the Navien listings themselves come with a certification-and-call-for-pricing gate that the rest of Ferguson’s open-pricing catalog (A.O. Smith, Eemax, Rheem) doesn’t share, and the site itself is mid-transition from its old Build.com name into the unified Ferguson Home brand. If open pricing with zero gating matters more than Navien access, our SupplyHouse.com tankless water heater guide covers that side of the wholesale channel. For retail-shelf shopping with bundled installation instead, see our Home Depot and Costco guides, or our best tankless water heater guide for the full brand field regardless of where you ultimately buy.