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Written from the listing's specs, not from our own use · How we rate
We like the Bosch Tronic 6100 (27 kW) for the mix: 27 kW at 240 V and a 5-year warranty. It is a good match for two showers at once where gas is not an option, at 6.6/10 on its documented specs.
| Brand | Bosch |
|---|---|
| Category | Electric tankless water heaters |
| Fuel | Electric |
| Stated heating power | 27 kW |
| Stated warranty | 5 years |
| ASIN | B0BWKCVFTW |
Full listing title: Bosch Thermotechnology Tronic 6100 Electric Tankless Water Heater, 27 kW, White
| Fuel | ElectricFull listing title |
|---|---|
| Stated heating power | 27 kWFull listing title |
Rated from the listing's specs, no buyer reviews yet
What it's made for: two showers at once where gas is not an option.
Two electric tankless heaters of about the same power, closest to it on our rating, each with a dated price.
The heating power the listing states. At 240 V it draws about 113 A. That's the line to show your electrician before anything else: the panel decides whether this fits, not the shower.
What it has going for it
5-year warranty. 5 years, per the listing. Read what it needs from you: many makers ask for a licensed install and regular flushing to keep it valid.
Warm tap water: where it comes in around 62 °F (much of the South), 27 kW gives about 4.3 GPM of 105 °F water on our calculator's maths. That's two 2 GPM showers at once.
A cold January: where it comes in at 42 °F, it's about 2.9 GPM, one 2 GPM shower at a time. Up north, that's the figure to size against, and it's why the honest answer is sometimes a second unit or gas.
Warranty & support: 5-year warranty, as stated in the listing.
That is the maker's promise, not ours. Keep the invoice, register the Bosch Tronic 6100 (27 kW) if the maker asks, and read the install conditions: many tankless warranties need a licensed install and regular flushing.
At the price on Sep 30, 2026, each kW of stated heating power works out at about $23.58 (price ÷ stated kW, our arithmetic). That puts it in the pricier third of the 27 whole-house electric tankless heaters we have a price and a stated power for.
Budget for the electrician as well: new double-pole breakers, thick wire from the panel and, if the panel is full, an upgrade.
The button opens the exact listing (ASIN B0BWKCVFTW), where today's price, stock and seller apply.
Colder tap water where you live? The WINTEMP WN-36kW Electric, 240V (8.1/10) is rated 36 kW.
Panel short on spare amps? The Rheem 18 kW Electric, 240V (9.3/10) is rated 18 kW, about 75 A at 240 V.
Only one sink far from the heater? The ThermoMate 14 kW Electric, 240V (7.9/10) is a 14 kW point-of-use unit.
Our take
Our favourite thing about the Bosch Tronic 6100 (27 kW) is 27 kW at 240 V, closely followed by a 5-year warranty. No buyer reviews yet, so the Bosch Tronic 6100 (27 kW) has to win you over on paper. The one thing that bugs us: no stated self-modulation, while most picks here have it. We'd pick it if your house has no gas and a 200 A panel with room to spare; otherwise, put it next to the Vancepic 18 kW Electric (240V) first.
New breakers, the unit on the wall next to the old tank's spot, water in and out. An electrician does the panel side.
Hot in a few seconds once the water in the pipes has passed. Set it, then leave it.
With 42 °F water coming in, 27 kW gives about 2.9 GPM at 105 °F on our calculator's maths. Low-flow shower heads stretch that further.
Clean the inlet screen and flush out scale on hard water. Our flushing and descaling guide has the routine.
Before you order the Bosch Tronic 6100 (27 kW), check your panel: the listing doesn't spell out the breakers, so ask before an electrician quotes the job.
Take a photo of the panel label (main breaker size and free slots) and send it to the electrician with the listing. Our electrical requirements guide explains what they will look for.
On our calculator's maths, 27 kW gives about 2.9 GPM with 42 °F winter water and 4.3 GPM with 62 °F water. Our flow-rate calculator does it for your region.
Hardwired 240 V work needs a licensed electrician and often a permit. Our install cost guide shows what usually ends up on the quote.
Hard water still builds up on the elements and the inlet screen. Our flushing and descaling guide covers the routine.
How the Bosch Tronic 6100 (27 kW) stacks up against the closest alternative, the Vancepic 18 kW Electric (240V).
| Criterion | Bosch Tronic 6100, 27 kW | Vancepic 18 kW Electric, 240V |
|---|---|---|
| Our rating | 6.6/10 | 6.8/10 |
| Heating power | 27 kW | 18 kW |
| Voltage | Not stated | 240 V |
| Self-modulating | Not stated | Stated |
| Warranty | 5 years | 2 years |
| Buyer reviews | None captured | 19 · 3.6/5 |
Pick the Vancepic 18 kW Electric (240V) if you want our higher-rated option (6.8/10), with self-modulating power; stay with the Bosch Tronic 6100 (27 kW) for more power (27 kW) and a longer stated warranty (5 years).
We rate it 6.6/10 (good). The rating comes from its documented listing alone, as no customer-review record is captured yet.
The listing states a heating power of 27 kW. The headline flow is a mild-weather number: with cold winter water coming in, the same unit gives you less. Read the maker's flow chart at your winter rise, or let our flow-rate calculator do the sums.
The listing doesn't state the voltage, so check the maker's documents. A licensed electrician checks the panel, the breakers and the wiring before it goes on the wall.
Its listing states 27 kW of heating power and a 5-year warranty. These are the seller's figures, not our measurements: how steady the temperature is in your shower and how it copes with your winter water can't be read from a listing.
Your panel: take a photo of the panel label (main breaker size and free slots) and send it to the electrician with the listing. Our electrical requirements guide explains what they will look for. Your winter flow: on our calculator's maths, 27 kW gives about 2.9 GPM with 42 °F winter water and 4.3 GPM with 62 °F water. Our flow-rate calculator does it for your region. The install: hardwired 240 V work needs a licensed electrician and often a permit. Our install cost guide shows what usually ends up on the quote. Scale: hard water still builds up on the elements and the inlet screen. Our flushing and descaling guide covers the routine.
We link to the exact listing on Amazon, where today's price, stock and seller apply. It is an affiliate link, and it has no effect on the rating.
No, we haven't used it ourselves. Everything on this page comes from its listing, read line by line and weighed with our published formula.