Buried in the service level (press P and + simultaneously for 5 seconds) is the FAC parameter. The manual explicitly warns:
Setting
FAC = 1and confirming will erase every custom parameter and restore Siemens factory settings. Use only as a last resort.
After a factory reset, you must re-enter InP1, SCL, SCH, Cntr, and t1.
If you have the original Siemens manual (≈80–100 pages), here's a roadmap of its key chapters:
| Section | Content | Why You Need It |
|--------|---------|----------------|
| 1-3 | Safety instructions & mounting/wiring | Prevents electrical damage & personal injury |
| 4 | Commissioning & basic setup | First power-on & language selection |
| 5 | Configuration (Configuration Level) | Setting input type, output logic, setpoint limits |
| 6 | Parameter Level (PID & control tuning) | Adjusting P-band, integral time, derivative time |
| 7 | Special functions (cascade, 2nd setpoint) | Advanced process control |
| 8 | Diagnostics & error codes | Troubleshooting faults like E1, E5, L1 |
| 9 | Technical data | Electrical ratings, accuracy, environmental limits |
| Appendix | Wiring diagrams & terminal assignments | Physical installation |
💡 Pro Tip: Use the index at the back of the manual to quickly find error codes or parameter numbers (e.g.,
P101= Input type selection).
Verification: The manual recommends applying a known current (e.g., 12 mA) using a calibrator and checking that the display reads 8.0 bar (midpoint of 0-16).
“Emergency Code Grabber” – snap a photo of the RWF40 display’s blinking LED pattern or 7-segment code, and the tool matches it to manual fault tables instantly (no page flipping). siemens rwf40 manual
Siemens RWF40 is a compact universal digital controller specifically engineered for high-precision boiler temperature and pressure control. Designed for use with modulating or multistage burners, it provides a specialized solution for heat-generating plants through a versatile interface and robust industrial design. Thermal Solutions LLC Core Functionality & Performance
The RWF40 excels in its dual role as both a basic thermostat/pressurestat and a sophisticated PID controller. Industrial Stores Operating Modes
: It supports 2-position control (on/off for 2-stage burners) and 3-position floating control for modulating burners without requiring feedback from the air damper. Self-Setting (Auto-Tune)
: A standard feature that automatically determines optimal PID/PI control parameters, significantly simplifying commissioning for complex boiler systems. Setpoint Versatility
: Setpoints can be adjusted locally on the unit or via an external signal. It also supports weather-dependent setpoint shifting when paired with an outside sensor (like the Siemens QAC22 Technical Specifications & Build RWF40... Compact Universal Controllers
Siemens RWF40 Go to product viewer dialog for this item. is a compact universal digital controller engineered specifically for the precision management of heat-generating plants, such as boiler systems and modulating burners. This essay examines the core technical functionalities, operational flexibility, and installation requirements of the
as outlined in its official documentation and technical manuals. Advanced Control Mechanisms Buried in the service level (press P and
At the heart of the RWF40's design is its ability to operate as a high-performance digital PID (Proportional-Integral-Derivative) controller. This allows it to manage complex heating processes through either a three-position output or an optional analog output. Key operational features described in the RWF40 Technical Literature include:
Modulating and Two-Stage Operation: The unit can seamlessly switch between modulating PID control for high demand and two-stage control for lower-fire operations.
Self-Setting Function: To simplify commissioning, the RWF40 includes a standard auto-tuning (self-setting) feature that automatically determines the optimal PID parameters for the specific thermal system.
Dual Setpoint Management: Users can configure internal or external setpoints, with the ability to shift setpoints based on weather conditions using external sensors. Technical Specifications and Design
is built for industrial environments, featuring a flush panel mounting design with a dual 4-digit 7-segment display for real-time monitoring of actual values (red) and setpoints (green).
Input Versatility: The controller accepts various inputs, including Pt100/Pt1000 resistance sensors, thermocouples (Type K, J, N, etc.), and standard linear signals like 4...20 mA or 0...10 V.
Durability: According to the RWF40 Tech Brochure, it carries an IP65 protection rating for the front panel and operates reliably in temperatures ranging from -20°C to +50°C. Setting FAC = 1 and confirming will erase
Communication: Higher-tier models (e.g., RWF40.002B97) support an optional RS-485 interface using the Modbus protocol, facilitating integration into building management systems (BMS) or data networks. Operational Safety and Installation
The RWF40 User Manual emphasizes that installation and commissioning must be performed by qualified personnel to ensure compliance with international safety standards like VDE 0100 and DIN 0631. Users are strictly warned not to modify or open the controller housing, as this voids the warranty and poses electrical risks. Configuration is performed using four front-facing buttons, allowing for adjustments to be made even while the burner is active. Conclusion RWF40... Compact Universal Controllers
Siemens RWF40 is a compact universal controller designed primarily for temperature and pressure regulation in burner and boiler applications. While the manual does not list a specific feature explicitly titled "Draft Feature," it includes several core functionalities used to manage draft-related variables like pressure and air damper positioning. Thermal Solutions LLC Key Control Features Operating Modes Low-fire operation
: Acts as a two-position controller (on/off) to maintain a setpoint. High-fire operation
: Operates as a modulating or 2-stage controller to meet higher heat demands. Dual Setpoint Management
: Allows for a primary setpoint and an external setpoint shift or changeover via binary inputs. Auto/Manual Control : Users can manually drive the burner output or engage the Self-setting (Auto-tune) function to optimize PID parameters automatically. Limit Comparator
: Offers 8 different functions to monitor if values exceed or fall below adjustable thresholds, often used for safety or process signaling. Thermal Solutions LLC Input and Output Capabilities RWF40... Compact Universal Controllers - Thermal Solutions
When the RWF40 displays an error, the manual provides a clear diagnostic. Below is a quick reference based on the original Siemens documentation:
| Error Code | Meaning | Manual-Recommended Action |
|------------|---------|---------------------------|
| E001 | Sensor break (input 1) | Check Pt100 wiring for open circuit. |
| E002 | Sensor short circuit | Check for sensor short or moisture in terminal block. |
| E003 | Input signal out of range | 4-20 mA below 3.6 mA or above 21 mA. Check loop power. |
| E009 | Actuator fault | The motor did not reach position after full pulse. Check linkage. |
| E011 | Internal parameter corruption | Reset to factory defaults via parameter FAC = 1. |