1. Introduction
The Doulton M15 UltraCarb Ceramic Drinking Water Filter Candle is designed to provide clean, great-tasting water by effectively reducing a wide range of contaminants. This filter is compatible with various Franke water filtration systems, including Franke 02, Triflow, Filterflow, and both 1st Generation Steel and 2nd Generation Plastic housings, as well as FRCNSTR100 systems. This manual provides essential information for the proper installation, operation, and maintenance of your filter candle.

Image 1: Doulton M15 UltraCarb Ceramic Drinking Water Filter Candle with packaging.
Video 1: Official Doulton video demonstrating the UltraCarb Ceramic filter and its benefits.
2. Compatibility
The Doulton M15 UltraCarb Ceramic Drinking Water Filter Candle (Model W9223021) is designed for use with the following water filtration systems:
- Franke 02 systems
- Franke Triflow systems
- Filterflow systems
- All 1st Generation Steel housings
- All 2nd Generation Plastic housings
- FRCNSTR100 systems
This filter features an M15 thread and measures 10 inches in length, ensuring a proper fit for the specified systems.

Image 2: Close-up of the Doulton M15 filter, highlighting the M15 thread for compatibility.
3. Features and Benefits
The Doulton M15 UltraCarb filter candle offers advanced filtration capabilities, providing numerous benefits for your drinking water:
- Comprehensive Contaminant Reduction: Effectively removes suspended solids, cloudiness, parasites, pathogenic bacteria, chlorine, bad taste, lead, and over 230 other impurities from your drinking water.
- Improved Water Quality: Delivers great-tasting water for your entire family, enhancing the flavor of beverages and food prepared with filtered water.
- Sustainable Design: Made from 100% natural ceramic, this filter generates 80% less plastic waste compared to synthetic cartridge filters.
- Unique Ceramic Technology: Features self-sterilizing and re-cleanable ceramic. The BioTect protection prevents bacterial growth on or through the filter medium.
- Health-Promoting Minerals: Designed to retain essential, health-promoting minerals in your water while filtering out harmful substances.

Image 3: Diagram illustrating how Doulton ceramic water filters reduce contaminants like bacteria, sediment, particles, and metals, while preserving essential minerals for improved health, taste, and smell.

Image 4: A family enjoying clean, filtered water, highlighting the benefit of Doulton water filters for daily use.
4. Setup and Installation
Always refer to the specific installation instructions provided with your Franke or compatible water filtration system housing. The following are general steps for replacing a filter candle:
- Turn Off Water Supply: Locate the cold water supply valve to your filtration system and turn it off.
- Relieve Pressure: Open the filtered water tap to release any remaining pressure in the system.
- Remove Housing: Carefully unscrew the filter housing from the system. Be prepared for some residual water to spill.
- Remove Old Filter: Extract the used Doulton filter candle from the housing.
- Clean Housing: Clean the inside of the filter housing with warm, soapy water and rinse thoroughly. Inspect the O-rings for any damage and replace if necessary.
- Install New Filter: Insert the new Doulton M15 UltraCarb filter candle into the housing, ensuring it is seated correctly.
- Reassemble Housing: Screw the filter housing back onto the system, hand-tightening only. Do not overtighten.
- Restore Water Supply: Slowly turn on the cold water supply valve. Check for leaks.
- Flush System: Open the filtered water tap and allow water to run for 5-10 minutes to flush out any air and fine ceramic particles. The water may appear cloudy initially; this is normal and will clear.
For detailed visual guidance, consult your system's original manual or manufacturer's website.
5. Operating Instructions
Once installed and flushed, your Doulton M15 UltraCarb filter candle operates automatically with your water filtration system. Simply open your filtered water tap to dispense clean, filtered water. The filter is designed for continuous use and requires no special operational procedures beyond regular maintenance.
6. Maintenance
Regular maintenance ensures optimal performance and longevity of your Doulton M15 UltraCarb filter candle:
- Cleaning: The ceramic surface of the filter can be cleaned to restore flow rate. If you notice a significant reduction in water flow, remove the filter candle (following the first few steps of the installation guide) and gently scrub the ceramic surface with a stiff brush or scouring pad under running water. Do not use soap or detergents. Rinse thoroughly before reinstallation.
- Replacement: The filter candle should be replaced periodically, typically every 6 to 12 months, depending on water quality and usage. Even with cleaning, the flow rate will eventually slow, indicating the need for replacement. Refer to your system's manufacturer recommendations for specific replacement intervals.
7. Troubleshooting
If you encounter issues with your Doulton M15 UltraCarb filter, consider the following:
- Reduced Water Flow: This is typically caused by accumulated sediment on the ceramic surface. Perform a filter cleaning as described in the Maintenance section. If flow does not improve, the filter may be at the end of its lifespan and require replacement.
- Unusual Taste or Odor: If the filtered water develops an unusual taste or odor, it may indicate that the filter's capacity for contaminant reduction has been exhausted. Replace the filter candle. Ensure the system was properly flushed after installation.
- Leaks: Check all connections and O-rings. Ensure the filter housing is hand-tightened securely and that O-rings are properly seated and not damaged. If O-rings are damaged, they should be replaced.
- Cloudy Water After Installation: A slight cloudiness immediately after installation and flushing is normal due to air and fine ceramic particles. This should clear within a few minutes of running water. If cloudiness persists, re-flush the system for a longer period.
8. Specifications
| Attribute | Value |
|---|---|
| Model Number | W9223021 |
| Material | Ceramic, Activated Carbon, Metal, Resin |
| Product Dimensions (D x W x H) | 3"D x 3"W x 10"H |
| Item Weight | 1.6 Pounds |
| External Testing Certification | NSF |
| Product Benefits | Reduces Chlorine, Lead, Bacteria, Cysts, Parasites, Sediment, Bad Taste, Odor |
| Unit Count | 2 Count (as typically sold in a pack) |
9. Warranty and Support
For information regarding product warranty, technical support, or to purchase replacement parts, please visit the official Doulton Water website or contact their customer service department. Keep your purchase receipt as proof of purchase for any warranty claims.

Image 5: A child enjoying clean water, symbolizing Doulton's commitment to providing safe and fresh drinking water.