1. Safety Precautions:
- Ensure the boiler is turned off and disconnected from the electrical power source.
- Allow the boiler to cool down completely before handling any components.
2. Identify the Flow Switch:
- Locate the flow switch in the boiler. It is typically installed on the inlet or outlet water pipe and connected to the control system.
3. Visual Inspection:
- Inspect the flow switch for any physical damage, corrosion, or loose connections. Ensure that there are no obstructions blocking the water path through the switch.
4. Manual Operation:
- Gently turn the impeller or flapper of the flow switch to simulate water flow. Observe if the switch activates and deactivates smoothly without any resistance.
5. Continuity Check:
- Disconnect the electrical connections to the flow switch.
- Use a multimeter set to continuity mode.
- Touch one probe of the multimeter to one terminal of the flow switch and the other probe to the other terminal.
- If the switch is closed (water flowing), there should be continuity (a closed circuit with a beep).
- Repeat the process for the other switch terminals.
6. Connect to Power:
- Reconnect the electrical connections to the flow switch.
7. Boiler Function Test:
- Turn on the boiler and allow it to fill with water.
- Observe if the flow switch initiates the appropriate actions (e.g., starting the boiler or activating a pump) when water flow is detected.
8. No Water Flow Test:
- Turn off the water supply to the boiler, simulating a no-flow condition.
- Check if the flow switch deactivates and triggers the expected response in the boiler control system.
9. Reset the Flow Switch:
- Some flow switches have a reset button. Press it if the switch does not respond correctly.
If you find any issues with the flow switch during testing, it may require cleaning, repair, or replacement to ensure proper boiler operation and safety. If the problem persists or you are unsure about any steps, consult with a qualified heating technician.
