Bosch Tronic 3000 T 4-Gallon Mini Tank Water Heater

The Bosch Tronic 3000 T 4-Gallon Mini Tank Water Heater (ES4) is the small point-of-use electric mini-tank for under-sink installs, RVs, boats, garages, workshops, and other applications where running hot-water plumbing from the main heater isn't practical. 4-gallon capacity, 1440W element, 120V plug-in (no 240V wiring needed), 6-year warranty.

Headline specifications

• Capacity: 4 gallons
• Fuel: Electric, 120V plug-in
• Element: 1440W
• Recovery: ~7 GPH at 90°F rise
• First Hour Delivery: ~6 GPH
• Warranty: 6-year tank, 2-year parts
• Maximum temperature: 145°F
• Dimensions: 14" H × 14" W × 14" D
• Weight: 35 lbs (empty)
• Mounting: wall-mount bracket included

Who this model is for

Point-of-use applications: under-sink for a remote bathroom or kitchen far from the main water heater, RV / fifth-wheel / boat installs, garage utility sink, workshop hand-wash station, basement wet bar, pool-house bathroom, detached ADU where running hot-water plumbing from the house is impractical. The 120V plug-in eliminates the need for 240V electrical work — plugs into a standard outlet.

Wrong product for whole-house applications. The 4-gallon capacity is for single-fixture point-of-use only. For a small bathroom (sink + shower + toilet), the 7-gallon Tronic 3000 T 7G or larger 10G+ models are correct.

Where the Tronic 3000 T 4G beats the alternatives

Vs running hot-water line from main heater: for a single remote sink 30+ ft from the main heater, the Tronic eliminates ~$300–$800 in plumbing labor and the chronic hot-water-wait-time problem. Even if the math doesn't show payback on plumbing labor, the user experience win (instant hot water at the remote sink) often justifies the install.

Vs Eemax/Stiebel point-of-use tankless electric: tankless point-of-use needs 240V wiring and 30+ amp capacity. The Tronic plugs into 120V. For under-sink retrofit without electrical work, Tronic wins.

Vs larger 7G/10G mini-tank: 4G saves ~$50 upfront and fits very tight cabinet installs. If your demand exceeds 4 gallons in a row (full hand-wash sink + small fill-up), step up to 7G.

Where it falls short

4 gallons is small. A single hand-wash or dish rinse uses 1–2 gallons; the tank recovers slowly (7 GPH = ~9 minutes for full reheat). For higher-demand point-of-use, the 7G or 10G is right.

1440W element is the limit at 120V (any higher would exceed 15-amp circuit). Recovery is slow. Don't expect tankless-class instant hot water — there's a refill delay after heavy use.

6-year warranty is class-standard for point-of-use mini-tanks.

14"×14"×14" cube fits most under-sink cabinets but verify clearance — some compact vanities won't accommodate.

No smart features. No leak detection. No app integration. It's a mini-tank.

Install considerations

Standard 120V grounded outlet — no electrical work required. 1/2" NPT inlet/outlet. Wall-mount bracket included. Drain pan recommended for under-sink installs to protect cabinet floor.

Install cost: $150–$350 for plumber to plumb inlet/outlet (or DIY-able with basic plumbing skill).

Maintenance

• Annual flush via drain valve
• Anode check at year 4
• T&P valve test annually
• Element inspection at year 5 (rare to fail at low wattage)

Bottom line

The Bosch Tronic 3000 T 4G is the small point-of-use electric mini-tank for under-sink and remote-fixture applications. 120V plug-in, 4-gallon capacity, 6-year warranty. Right pick for a single remote sink or RV/boat install. For small bathroom applications, step up to the 7-gallon. For whole-house, this is the wrong category — pivot to a 30G+ tank or a tankless.