Bosch Tronic 6100 18 kW Electric Tankless Water Heater - Compact POU

Our review of the Bosch Tronic 6100 finds it best suited for point-of-use installations where space and instant hot water matter most. This compact 18 kW electric tankless water heater is designed to fit under sinks and provide an endless supply of hot water for one or more commercial or residential sinks, and the single biggest reason to buy is its combination of low activation flow and high thermal efficiency that cuts standby waste and simplifies installation in tight spaces.

Key Features

• 18 kW power: Delivers enough heating capacity for point-of-use sinks without requiring a large footprint for installation.
• Compact and lightweight: Small housing allows the unit to be installed under sinks or in shallow cabinets where a storage tank would not fit.
• Low activation flow: Activates at approximately 0.55 GPM, making it well suited to modern low-flow commercial and residential faucets.
• High thermal efficiency: About 96% thermal efficiency minimizes energy lost to standby heat, saving on electricity and water over time.
• Easy maintenance: As an electric tankless design with no stored water, it requires virtually no venting and little routine maintenance.
• Durable exterior: Encased in a white plastic housing that blends with surroundings for discreet installation.

Who It's For

The Bosch Tronic 6100 is ideal for homeowners, small commercial operators, and facility managers who need reliable point-of-use hot water for sinks in restrooms, break rooms, or remote fixtures. Its compact design is particularly helpful in retrofit jobs where under-sink clearance is limited and a quick swap from a storage tank is desired.

It is not designed as a whole-house solution; buyers requiring multiple simultaneous high-flow outlets or whole-house capacity should look at larger tankless models or centralized systems. Also, locations without adequate electrical capacity for an 18 kW load will need an electrical upgrade before installation.

Pros & Cons

Pros

• Compact form factor fits under sinks and in tight spaces with minimal visual impact.
• Very low activation flow rate works well with low-flow faucets common in commercial settings.
• High thermal efficiency reduces standby energy waste compared with storage tanks.

Cons

• At 18 kW it requires significant electrical capacity, so some sites may need panel upgrades.

Specifications

Brand	Bosch Thermotechnology
Model Series	Tronic 6100C
Power	18 kW
Activation Flow Rate	Approximately 0.55 GPM
Thermal Efficiency	About 96% (no standby loss)
Connections	3/4 in NPT cold and hot water fittings
Housing	Durable white plastic

Our Verdict

The Bosch Tronic 6100 is a reliable, space-saving point-of-use electric tankless heater that delivers instant hot water with high efficiency, making it a sensible upgrade from small electric storage tanks. Buy it if you need under-sink hot water for individual sinks or light commercial fixtures and have the electrical capacity to support an 18 kW unit; its low maintenance and compact profile offer good long-term value.

Frequently Asked Questions

Can this unit replace a small electric storage tank?
The Tronic 6100 is suitable to replace small storage tanks for point-of-use sinks, and the 3/4 in NPT fittings simplify plumbing swaps.

Is any special ventilation required?
No venting is required because this is an electric tankless heater that does not store or burn fuel.

Will it work with low-flow faucets?
Yes, it activates at about 0.55 GPM, so it pairs well with low-flow commercial and residential faucets.