Fogatti 18 kW
Amazon customer rating as of
Tankless Geek editorial score: 4.3/5
The Fogatti 18 kW is a budget 240-volt electric tankless heater built for small whole-home or multi-point service where gas isn't an option. It self-adjusts wattage to demand, holds temperature to about ±1 °F across an 86–140 °F range, and mounts in a slim 17.1 × 12.9 × 3.9 in cabinet with an LED display — all at a price well under the mainstream electric brands.
Fogatti advertises "up to 4.4 GPM," but that figure only holds with very warm inlet water. Run the numbers honestly and 18 kW delivers about 3.5 GPM at a 35 °F rise and closer to 2 GPM once inlet water turns cold — the same physics that governs every 18 kW electric unit. Treat it as a warm-climate two-fixture heater or a cold-climate single-shower unit and it's a lot of capacity for the money; expect the ~75 A of electrical draw (two 40 A breakers, 8-gauge wire) to be the real cost and gating factor.
Key Features
Best Use Cases
Our Verdict
A value-priced 18 kW electric unit that performs like any 18 kW unit — well in warm climates, modestly in the cold — once you get past the advertised 4.4 GPM optimism. Worth a look if you want mainstream capacity at a budget price and your panel can supply ~75 A. Just size it to a realistic winter flow, not the box number.
Technical Specifications
| Power | 18 kW @ 240 V (~75 A draw) |
|---|---|
| Electrical | Two 40 A double-pole breakers · 8-gauge wire |
| Advertised flow | Up to 4.4 GPM (warm inlet only) |
| Temp range | 86–140 °F, ±1 °F control |
| Dimensions | 17.1 × 12.9 × 3.9 in |
| Certification | ETL certified |
Specifications verified against the linked source documents. See Sources below.
How much hot water you'll actually get
Usable flow drops as incoming water gets colder. Figures are calculated from rated output (kW) and labeled as such — not bench-tested by us.
| Temperature rise | Typical scenario | Usable flow |
|---|---|---|
| 35 °F | Warm climate (75 °F in → 110 °F) | 3.5 GPM |
| 45 °F | Mild climate (65 °F in → 110 °F) | 2.7 GPM |
| 60 °F | Cool climate (50 °F in → 110 °F) | 2 GPM |
| 70 °F | Cold climate (40 °F in → 110 °F) | 1.8 GPM |
Usable flow at a 110 °F target from 18 kW: kW × 3412 ÷ (ΔF × 500). The advertised 4.4 GPM requires only a ~28 °F rise (very warm inlet) — plan around these figures instead.
Pros
Cons
Buy it if…
- Warm/mild-climate small homes needing two modest fixtures
- Budget buyers wanting 18 kW capacity below premium prices
- Point-of-use or addition heating where gas isn't available
- Panels with room for two 40 A double-pole breakers
Skip it if…
- Cold-climate homes needing two simultaneous showers
- Buyers who need the advertised 4.4 GPM in winter (unrealistic)
- Anyone wanting a long, established warranty/support track record
Installation Requirements
Professional vs DIY
Two-circuit wiring at ~75 A is best handled by an electrician; verify panel space first.
Advertised 4.4 GPM is warm-inlet only — expect noticeably less in cold-water regions.
Gas and electrical work should be done by a licensed professional, and most installs require a permit and must meet local building codes — DIY work can void the manufacturer warranty. Always confirm the unit's own manual for exact clearances, venting, and sizing.
What owners report
Themes summarized from retailer customer feedback (4.7/5 Amazon customer rating, 26 ratings, as of 2026-09-06). These are owner opinions, not our own bench testing.
Early owners highlight mainstream 18 kW capacity at a notably lower price than the established electric brands.
The slim cabinet and clear LED display draw praise for easy DIY-friendly mounting where a licensed electrician handles the circuit.
As with any 18 kW unit, the 4.4 GPM claim only holds with warm inlet water; cold-weather flow is lower.
With a small review base, long-term reliability and support are less proven than mainstream brands — keep installation records for the warranty.
Fogatti 18 kW FAQ
Is 4.4 GPM realistic?+
Only with very warm incoming water (about a 28 °F rise). At a typical 35 °F rise an 18 kW unit delivers ~3.5 GPM, and less in cold weather — plan around the temperature-rise table.
What electrical service does it need?+
About 75 A of draw at 240 V — two 40 A double-pole breakers and 8-gauge conductors on a dedicated circuit. Confirm your panel capacity first.
Can it run a whole house?+
A small one in a warm or mild climate (a shower plus a sink). In cold climates treat it as a single-shower unit.
What temperature rise can the Fogatti 18 kW actually deliver?+
The advertised 4.4 GPM assumes an already-warm inlet. Estimated from its 18 kW output (about 61,400 BTU/h), realistic usable flow is roughly 2.7 GPM at a 45 °F rise and about 1.7 GPM at a 70 °F winter rise. In practice that means one comfortable shower in most climates, or two low-flow fixtures where groundwater is warm. If you need genuine simultaneous whole-home output in a cold region, an electric unit of this size will fall short — plan around your coldest incoming water temperature, not the headline number.
Product sources
Specifications verified 2026-09-06. Manufacturer documents are treated as the primary source for model specifications. Retailer pages are used only for customer ratings and owner-feedback themes.
- Fogatti 18 kW electric — Amazon listing (accessed 2026-09-06)
- Fogatti 18 kW electric — retailer spec page (accessed 2026-09-06)
Price range from leading retailers
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