Runxin F71B1 Automatic Filter Valve
The Runxin F71B1 automatic filter valve is a top-mount control head designed to automate cleaning cycles on sand, activated carbon, and other media filtration systems. Replacing manual multiport valves, it sequences service → backwash → fast rinse → service based on either programmed time intervals or flow (meter) triggers.
An integrated LED display shows operational status and mode, while the controller retains programmed parameters after power outages. A button-lock feature prevents accidental setting changes, and manual rinse initiation is available directly from the interface.
The F71B1 is ideal for residential and small commercial filtration applications where automated backwash improves water quality consistency and reduces maintenance demands.
📐 Filter Tank Sizing Guide
Proper tank sizing ensures effective backwashing and filtration performance.
| Tank Diameter | Typical Use |
| 6″ | Small residential filtration |
| 8″ | Standard home filtration systems |
| 10″ | Higher capacity residential setups |
Sizing Notes
- Larger diameter tanks hold more media and may need less frequent backwash.
- Ensure your selected tank is compatible with the 2.5″-8 NPSM base and riser pipe size.
🕒 Backwash Timing Recommendations
The F71B1 can be programmed to backwash based on either time or volume.
Time-Based Backwash
| Water Quality/Use | Suggested Interval |
| Light sediment | Every 2–3 days |
| Moderate sediment | Every 1–2 days |
| High sediment load | Daily or shorter intervals |
Flow/Volume Backwash (Meter Type)
| Water Volume | Backwash Trigger |
| Low daily use | ~3000–5000 L |
| Moderate daily use | ~2000–4000 L |
| High daily use | ~1500–3000 L |
Notes
- Use meter control when water usage fluctuates daily.
- Time scheduling is simpler when usage is regular.
📌 Practical Installation Advice
- Confirm vessel compatibility — ensure the tank head fits the 2.5″-8NPSM mounting base.
- Program settings — select either timer or meter mode based on usage.
- Check media type — glass or carbon filters work well with this valve.
- Monitor first cycles — adjust backwash frequency for water quality results.



