HVAC / Water Heaters
Bosch Therm 4600 Compact In 20L Instant Water Heater User Guide
Comprehensive user guide for the Bosch Therm 4600 Compact In 20L instant water heater. Includes technical specifications, installation diagrams, safety features, and operational requirements for optimal performance.
PDF source: español · summary: English
Quick answers from the manual
Quick answer
- The Bosch Therm 4600 Compact In 20L is an instant gas water heater. It requires a minimum water pressure (height difference > 1.5m) and proper ventilation. It features Opti Flow technology for intelligent fan and exhaust management. p. 1, 2
Key actions
- Ensure a height difference of > 1.5m between the water tank and the highest shower. p. 2
- Install a pressurizing pump if water pressure is insufficient. p. 2
Problems and fixes
Insufficient water pressure
Check height difference (>1.5m) or install a pressurizing pump.
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Technical specifications
| Parameter | Value | Meaning | Pages |
|---|---|---|---|
| Nominal Capacity | 20 L/min | Maximum water flow rate. | p. 2 |
| Power | 34.9 kW | Nominal power output. | p. 2 |
Where to find it in the PDF
- Product Overview p. 1
- Technical Specifications and Installation p. 2
Table of contents
Manual images
Click an image to enlargeQuick Guide
The Bosch Therm 4600 Compact In 20L is a gas-powered instant water heater designed for efficiency and safety. For optimal performance, ensure the height difference between your water tank and the highest shower is greater than 1.5 meters. If your water pressure is insufficient, the installation of a pressurizing pump is recommended to ensure continuous hot water.
Technical Specifications
- Gas Type: Natural or LP
- Nominal Capacity: 20 L/min
- Nominal Power: 34.9 kW
- Efficiency: 91%
- Dimensions: 364 x 568 x 175 mm
- Weight: 14 kg
- Electrical Connection: 127V 60Hz
- Water Connection: 1/2 inch
Installation Requirements
The unit requires proper ventilation in the installation area. There are two primary installation configurations:
- Standard Installation: Uses a concentric duct (60/100mm).
- Separated Duct Installation: Requires the use of an additional accessory (Part #7 736 995 095).
Ensure the air intake duct is always positioned below the exhaust duct.
Safety Features
The unit is equipped with several safety mechanisms to ensure reliable operation:
- Gas Leak Sensor: Detects potential leaks.
- Overheating Sensor: Prevents the unit from exceeding safe temperatures.
- Toxic Gas Sensor: Monitors the exhaust for toxic gases.
- Safety Valves: Two valves are included in the gas path.
Opti Flow Technology
This model features Bosch's patented Opti Flow technology, which includes:
- Intelligent management of the integrated fan.
- Automatic estimation of the exhaust duct length.
- Detection of obstructions in the exhaust duct.
- Atmospheric pressure compensation (automatic altitude adjustment).
Manufacturer information
Bosch
Practical help
Common problems
Low water pressure or failure to start
Ensure the height between the water tank and the highest shower is greater than 1.5m. If pressure is still insufficient, install a pressurizing pump.
Installation configuration issues
Verify if you are using a standard concentric duct or a separated duct system. Separated ducts require a specific accessory (#7 736 995 095).
Before use
- Verify that the gas type (Natural or LP) matches your local supply.
- Ensure the installation area has adequate ventilation.
- Check that the water pressure is at least 0.15 kg/cm² to open the gas valve.
- Confirm the height difference between the water tank and the highest shower is > 1.5m.
- Ensure the electrical connection is 127V 60Hz.
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Specs in practice
- Nominal Capacity
- The maximum flow rate of 20 L/min under standard conditions.
- Min. Water Pressure
- Minimum pressure required to trigger the gas valve (0.15 kg/cm²).
Images and diagrams
- Standard installation uses a concentric 60/100mm duct.
- Separated duct installation requires an accessory to split the air intake and exhaust.
Model compatibility
- Compatible with solar heating systems.
- Requires 127V 60Hz electrical supply for ignition and control.
Manual page author
Michael Turner
Technical manual editor