Servicing a Dual Carbon Unit
Purpose
To change the filter cartridges, clean and sanitize the system.
Tools and Supplies Needed
- Sump wrench - usually supplied with your system. A plastic wrench with a hole that fits around the sump (the lower section of the housing that the filter sits in)
- Optional (you may only need to do this every 3-4 years)
- Sharp pointed knife or needle tool - to remove the sump o-rings
- Lubricant (use only a good silicone lubricant) to re-lubricate the o-rings before returning them to the sump
- Catch pan - to catch the water which tends to spill when removing the sumps
- Sponge - to clean the sumps and the faucet
- Soap - for cleaning the sumps - preferably nonscented
- Chlorine - for sanitizing (Clorox is good)
- Pre and post filter cartridge replacements
- Paper towel or a clean cloth or rag
Procedure
- Turn off the water supply to the filter assembly - usually by closing a saddle valve or ball valve which directly connects your system to the main supply line. It is located between the cold water supply stop and the filter housing inlet.
- Open drinking water faucet to drain excess water and relieve pressure. If you don't do this, removing the sumps is virtually impossible.
- Position catch tray under the sumps. Remove both sumps by unscrewing them from the housing (the front of the sump -closest to you - will move to the left to unscrew), dump out the water and remove the filter cartridges and any washer/gasket that might stay in the sump.
- Optional (you may only need to do this every 3-4 years)
- Remove the o-rings and set aside.
- Wipe clean the o-ring groove and surrounding area with a paper towel.
- After washing out sumps and filling with bleach solution (see below steps), grease the o-rings with silicone lubricant and place into filled sumps. Make sure that the o-rings fit snuggly in their grooves
- Wash out the sumps with soap, and then rinse them well.
- Fill sumps with water and about a teaspoonful of chlorine. Let sit for 3-5 minutes.
- After 3-5 minutes, empty the sumps and place the appropriate filter cartridges.
(see note below**)
When you remove the plastic wrapping, don't touch the filter. You don't want to contaminate it with any bacteria that might be on your fingers. Peel the plastic off from the bottom while holding the top of the cartridge. Or you can use clean rubber or latex gloves. - Reattach the sumps to the housing. Screw on tightly using hand pressure, not the wrench.
- Open the supply line, and with the filter faucet open, let the filter system fill with water and watch for leaks.
- Allow the water to run for about a minute then shut off the faucet and watch for any leaks
- After waiting a short time to confirm there aren't any leaks, run water through the system for a couple of minutes by opening the drinking faucet. This lets residual carbon from the filters pass through the system and washes out any residual chlorine.
- You are finished. Enjoy your drinking water!
** Your system has a specific pre and post filter. When you reattach the sumps to the housing, make sure that the sump with the pre-filter attaches on the sump head which has the supply-line attached to it. The post-filter head is attached to the line that goes to your faucet. The typical prefilter is white with an enlarged "head" on one end - this head should be placed in the "up" position. The typical postfilter has green ends and a mesh covering and can be placed in either direction.
