Quick Answer: Bosch’s gas tankless line is winding down — the Greentherm/Therm 9000-series units (T9800/T9900) appear under “Discontinued Products” on Bosch’s own Home Comfort site, even though Home Depot, Lowes, and plumbing wholesalers still sell them in August 2026. If you want one anyway, the Greentherm T9900i SE199 is the best of the closeout stock — 199,000 BTU, 11.2 GPM at a 35°F rise, 0.96 UEF, built-in recirculation pump, Wi-Fi app, 15-year heat-exchanger warranty, $2,610.40 at Home Depot. For Bosch’s genuinely current tankless product, the electric point-of-use Tronic 3000 US9-2R (9 kW, 2.5 GPM, ~$263) carries no discontinuation flag at all — but know before you shop that Bosch’s electric line stops at point-of-use and never scales up to whole-home capacity.
Most “best Bosch tankless water heater” roundups treat Bosch like any other in-production brand and rank the Greentherm 9000 series against Rinnai and Rheem on specs alone. That misses the one fact that actually changes the buying decision: Bosch’s own website has already filed its gas tankless line under discontinued products, the same status Takagi units carried before that brand wound down. This guide separates what’s still genuinely current (Bosch’s electric point-of-use line) from what’s closeout inventory worth buying only at the right price (the gas line).
Our top picks at a glance
| Model | Best for | Type | BTU/kW | Peak flow | UEF/Efficiency | Price |
|---|---|---|---|---|---|---|
| Greentherm T9900i SE199 | Best overall (gas, closeout) | Condensing indoor, WiFi + pump | 199,000 BTU | 11.2 GPM @ 35°F rise | 0.96 UEF | $2,610.40 |
| Greentherm T9800 SE199 | Best value whole-home (gas) | Condensing indoor | 199,000 BTU | 11.2 GPM @ 35°F rise | 0.95 UEF | $1,926.60 |
| Greentherm T9800 SE160 | Best small-medium home (gas) | Condensing indoor | 160,000 BTU | 9.0 GPM @ 35°F rise | up to 0.95 UEF | $1,695.20 |
| Tronic 3000 US9-2R | Best current Bosch product (electric) | Point-of-use | 9 kW | 2.5 GPM | ~98% efficient | ~$263 |
| Tronic 3000 US12 | Best high-output point-of-use | Point-of-use | 12 kW | 2.3 GPM | ~98% efficient | ~$230 |
Gas prices are Home Depot listings checked August 8, 2026; electric prices vary more by retailer and are approximate. All GPM figures for the Greentherm line are manufacturer-rated at a 35°F rise, not the harsher 60°F winter-groundwater benchmark our flow rate guide recommends sizing against.
The discontinuation nobody flags
Search “Bosch tankless water heater discontinued” and you’ll land on Bosch’s own Home Comfort site, which files the Greentherm 9000 series — every T9800 and T9900 model — under Discontinued Water Heating Products, alongside a separate page for older Therm-series gas units. No press release accompanies it, and there’s no end-of-life banner on the retail listings themselves: Home Depot, Lowes, and wholesale suppliers like ProWaterHeaterSupply all still show current pricing and in-stock status for these SKUs as of August 2026.
That combination — manufacturer discontinuation notice, live retail inventory — is the identical pattern our Takagi brand guide documented for that line before it wound down completely. The practical read is the same too: you’re buying sell-through stock backed by a still-valid warranty, not a product Bosch will keep making. Bosch Thermotechnology is a division of the much larger Bosch Group, which lowers (though doesn’t eliminate) the risk of the warranty itself becoming worthless — the bigger long-run concern is parts and factory-trained service technicians thinning out over a 15-year heat-exchanger warranty term.
What hasn’t been flagged discontinued: Bosch’s Tronic 3000 electric point-of-use line. It carries no such notice anywhere on Bosch’s site, which makes it the honest answer to “does Bosch still make tankless water heaters” — yes, just not the gas whole-home kind anymore.
By the numbers
- 0.96 UEF on the flagship Greentherm T9900i SE199, among the highest efficiency ratings in the condensing gas tankless category — every model in the 9000 series is ENERGY STAR certified. — Bosch Home Comfort specifications
- 15-year heat-exchanger warranty on the Greentherm gas line (5-year parts, 1-year labor upon registration), a term that runs independent of whether Bosch keeps manufacturing the model. — Bosch Home Comfort warranty documentation
- 12 kW is the ceiling on Bosch’s entire electric tankless lineup (the Tronic 3000 US12) — well under the 27–36 kW a whole-home electric unit needs, confirming Bosch’s electric line is point-of-use only. — Bosch Home Comfort product specifications
1. Bosch Greentherm T9900i SE199 — Best Overall (Closeout)
Bosch Greentherm T9900i SE199 (199,000 BTU Condensing, WiFi + Pump)
- Bosch's flagship: the same 199,000 BTU condensing core as the plain T9900 SE199, plus a factory-built recirculation pump and Wi-Fi app control (iOS/Android) for remote temperature and usage monitoring.
- Shatterproof VBL glass front — a cosmetic touch, but one that signals which unit in the lineup Bosch positioned as premium.
- 0.96 UEF and full ENERGY STAR certification put it ahead of the non-i model and competitive with Rinnai's and Navien's flagships on paper.
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If you’re buying into the Greentherm line at all, buy the top of it. A built-in recirculation pump means you skip the compatibility headache our recirculating pump guide covers in depth — most aftermarket tank-style pumps aren’t rated for tankless use, and this one is already matched to the unit. The Wi-Fi app is a genuine convenience, not a gimmick tacked on for the spec sheet.
2. Bosch Greentherm T9800 SE199 — Best Value Whole-Home
Bosch Greentherm T9800 SE199 (199,000 BTU Condensing)
- Same 199,000 BTU, 11.2 GPM core hardware as the flagship T9900i, minus the built-in pump and Wi-Fi — a roughly $684 saving for buyers who don't need either.
- Full-size whole-home capacity: comfortably runs two fixtures at once in most climates, per the manufacturer's 35°F-rise rating.
- Same 15-year heat-exchanger, 5-year parts warranty as the rest of the 9000 series.
This is the pick for a straightforward whole-home replacement where a recirculation loop and app control aren’t on the wish list. It undercuts the flagship by nearly $700 for the same peak flow and nearly identical UEF (0.95 vs. 0.96) — the Wi-Fi and pump are genuinely optional extras, not efficiency upgrades.
3. Bosch Greentherm T9800 SE160 — Best Small-Medium Home
Bosch Greentherm T9800 SE160 (160,000 BTU Condensing)
- Sized for a 1–2 bathroom home rather than the full 199,000 BTU flagship — right-sizing avoids paying for burner capacity you'll never use.
- Also sold in an outdoor-rated SEO160 version for installations without indoor venting clearance.
- Same condensing efficiency tier and warranty terms as the bigger 199-series units, just in a smaller BTU footprint.
Buying the 199,000 BTU flagship for a small home is the classic tankless oversizing mistake covered in our sizing guide — the SE160 is Bosch’s answer for a household that doesn’t need to run three fixtures simultaneously, at a real price saving over the 199-series units.
4. Bosch Tronic 3000 US9-2R — Best Current Bosch Product
Bosch Tronic 3000 US9-2R (9 kW Point-of-Use Electric)
- The one Bosch tankless product carrying no discontinued-products flag anywhere on Bosch's own site — buying it doesn't come with the closeout-stock caveats attached to the gas line.
- ~98% efficient with minimal standby loss, since electric resistance heating has no combustion or venting losses to account for.
- Sized for a single fixture — a remote bathroom sink, a wet bar, a workshop — not a whole home's hot water.
If the goal is buying into Bosch’s actual ongoing product strategy rather than sell-through inventory, this is the honest pick. It won’t replace a whole-home gas unit — see the gap flagged below — but for a single point-of-use application it’s inexpensive, compact, and not shadowed by a discontinuation notice.
5. Bosch Tronic 3000 US12 — Best High-Output Point-of-Use
Bosch Tronic 3000 US12 (12 kW Point-of-Use Electric)
- The top of Bosch's electric tankless range — 12 kW is the ceiling for the entire Tronic 3000 lineup.
- Slightly lower peak GPM than the US9-2R despite the higher kW rating, since more of the higher wattage goes toward a bigger temperature rise rather than more flow.
- Best matched to a single low-flow shower or a fixture needing warmer output than the smaller US4/US7 models deliver.
This is as big as Bosch’s electric line gets — which is the point of the gap flagged below. If 12 kW and 2.3 GPM don’t cover what you need, Bosch doesn’t have a bigger electric unit to sell you.
The gap: Bosch has no whole-home electric tankless
Every other major electric tankless brand we cover — EcoSmart, Stiebel Eltron, A.O. Smith’s Signature line, and Rheem’s RTEX line in our electric roundup — builds units up to 27–36 kW that can run a full house on a large enough breaker panel. Bosch’s Tronic 3000 tops out at 12 kW, a single-fixture capacity by comparison. This isn’t a defect in Bosch’s electric line; it’s a deliberate scope limit, and it means Bosch simply isn’t a contender if what you’re shopping for is a whole-home electric replacement. For that use case, start with our best electric tankless water heater guide instead — Bosch won’t appear on that shortlist, and now you know why.
How to choose
- If you want a whole-home gas unit and don’t mind buying closeout stock: the Greentherm T9900i SE199 is the best of what’s left, backed by a 15-year heat-exchanger warranty that outlives the product line itself.
- If you want the same hardware for less and don’t need Wi-Fi or a built-in pump: the T9800 SE199 saves roughly $684 for nearly identical specs.
- If your home only needs 160,000 BTU of capacity: the T9800 SE160 avoids paying for flow you won’t use.
- If you want Bosch’s actual current, non-discontinued tankless product: the Tronic 3000 US9-2R or US12 point-of-use units are it — sized for one fixture, not a house.
- If you need whole-home electric tankless: skip Bosch entirely and compare EcoSmart, Stiebel Eltron, or Rheem’s RTEX line instead.
The bottom line
Bosch’s tankless story in 2026 splits cleanly in two: a gas whole-home line (Greentherm 9000 series) that Bosch’s own site already files as discontinued, and an electric point-of-use line (Tronic 3000) that’s still fully current but was never built to scale past a single fixture. If you want the gas hardware, the T9900i SE199 ($2,610.40) is the best of the remaining stock, backed by a 15-year heat-exchanger warranty that holds regardless of production status. If you want Bosch’s genuinely ongoing product, the Tronic 3000 US9-2R (~$263) is honest, inexpensive, and appropriately scoped — just don’t expect it to replace a whole-home unit. Still comparing brands? Our best tankless water heater roundup and best gas guide cover the in-production competition Bosch’s gas line no longer is.