The Veito Blue S is a compact, three-phase electric instantaneous (tankless) water heater rated at 18kW / 21kW, delivering continuous hot water the moment a tap is opened, with no storage cylinder required. Every component has been engineered for performance, from the heating element to the control knob, and an illuminated LCD display with rotary control lets the user set the exact output temperature required, adjustable in 0.5°C steps from 20°C to 60°C.
A built-in ECO panel allows power output to be scaled from 10% to 100%, giving fine control over both comfort and running cost, while an electronic sensor automatically adjusts heating power to compensate for changes in incoming water temperature. Weighing just 3.5kg and finished in a durable IP25-rated casing, the Blue S is designed for damp environments such as bathrooms and kitchens, and is compatible with solar thermal systems, automatically topping up the temperature of solar-heated water when needed.
18 / 21 kW
Selectable Power
400V 3PH
Power Supply
20–60°C
Temperature Range
IP25
Ingress Protection
3.5 kg
Weight
A
Energy Efficiency Class
Three-Phase Supply Required
The Blue S requires a three-phase 400V AC electrical supply and is not suitable for single-phase domestic systems. Installation must be carried out by a qualified, competent electrician in accordance with current UK wiring regulations.
Check Mains Water Pressure
The unit requires a minimum water pressure of 0.25 bar to operate correctly, with a maximum rated working pressure of 1 MPa (10 bar) at a closed outlet. Incoming mains pressure should be confirmed as suitable before installation.
Solar Thermal Compatible
The Blue S is designed to work alongside solar thermal hot water systems. If water arriving from the solar circuit is not warm enough, the unit automatically supplements the temperature shortfall, helping maximise the use of renewable heat while still guaranteeing the chosen output temperature.
Precise Digital Temperature Control
The illuminated LCD display and rotary selector allow output temperature to be set in 0.5°C increments from 20°C to 60°C, with a built-in sensor automatically adjusting heating power to hold that temperature steady.
ECO Panel for Power Management
An onboard ECO panel adjusts power output from 10% to 100%, giving direct control over energy usage and running costs alongside real-time monitoring of consumption and status.
Compact, Space-Saving Design
At 450 x 235 x 94mm and just 3.5kg, the Blue S fits into tight spaces where a conventional water heater or cylinder would not, without compromising on output.
IP25-Rated Wet Area Housing
The robust IP25-rated casing is built to withstand the damp conditions typical of bathrooms, kitchens and utility rooms, supporting long-term reliable operation.
Overheat Protection
Built-in overheat protection safeguards the unit and the property, automatically managing the heating element to prevent unsafe operating temperatures.
Multipoint, On-Demand Hot Water
As a true instantaneous heater, the Blue S delivers hot water in seconds with no standing losses, supplying multiple outlets and helping reduce water wastage compared with waiting for stored hot water to arrive.
General
Model
Blue S
Product Type
Instantaneous (tankless) electric water heater
Selectable Power Output
18 kW / 21 kW
Energy Efficiency Class
A
Weight
3.5 kg
Dimensions (H x W x D)
450 x 235 x 94mm
Electrical Supply
Line Voltage
400V AC
Phase
Three-phase
Frequency
50/60 Hz
Temperature & Water Circuit
Temperature Adjustment Range
20–60°C, in 0.5°C steps
Maximum Working Pressure
1 MPa (10 bar), closed outlet
Minimum Water Pressure
0.25 bar
Power Adjustment (ECO Panel)
10%–100%
Protection & Compliance
Ingress Protection Rating
IP25
Overheat Protection
Built-in
Solar Compatibility
Compatible with solar thermal systems
Can this heater be used on a single-phase supply?
No. The Blue S is designed for a three-phase 400V AC supply only and is not suitable for single-phase domestic electrical systems.
How is the water temperature controlled?
Via the illuminated LCD display and rotary control knob, which allows the output temperature to be set in 0.5°C increments between 20°C and 60°C. A built-in sensor continuously monitors and adjusts heating power to maintain the set point.
What does the ECO panel do?
The ECO panel lets the power output be scaled from 10% to 100%, giving control over energy consumption and running costs, with the illuminated display also showing water temperature and current power usage.
Can this be used with a solar hot water system?
Yes, the Blue S is compatible with solar thermal systems. If the water supplied from the solar circuit isn't hot enough, the unit automatically tops up the temperature to the selected set point.
Is it suitable for installation in a bathroom?
Yes, the unit carries an IP25 ingress protection rating, giving it suitable protection against moisture for installation in bathrooms, kitchens and similar wet areas, subject to the correct IP zone being observed.
Does it need professional installation?
Yes. As a three-phase electrical appliance, installation must be carried out by a qualified, competent electrician in accordance with current UK wiring regulations.
BTU & WATT Calculator
Room Dimensions
Room Type
Living Room
Bedroom
Kitchen
Bathroom
Conservatory
Hallway
Glazing Type
Single Glazed
Double Glazed
Triple Glazed
External Walls
0 Wall
1 Wall
2 Walls
3 Walls
4 Walls
Insulation Level
Poor
Average
Good (New Build)
Required Heating
0
Watts
0
BTUs
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