Watts M8421-COM User Manual

Scale Net™ Information

The flow thru the Scale Net™ system is upward. Therefore, the inlet and outlet connections are
opposite of traditional water treatment equipment.

The flow rate must not exceed the maximum specified flow rate of the system. A flow control devise
will be required for applications where flow rates may exceed the maximum specified flow rate.

Part Number Tank Size Pipe Size Max Service Flow

M8408-COM 8x35 1" 7 gpm
M8409-COM 9x35 1" 12 gpm
M8410-COM 10x54 1" 15 gpm
M8412-COM 12x52 1" 20 gpm
M8413-COM 13x54 1" 25 gpm
M8414-COM 14x54 1" 30 gpm

Installation Instructions:

1. Place system on a smooth flat surface.

2. Install the fittings and / or the bypass (see separate instructions). Slide the
nut on first then the split ring and o-ring.

3. Connect incoming cold water to the inlet of the system.

4. Connect system outlet to service water of the house.

5. Partially open a valve down stream of the system to allow the air to purge
from the system.

6. Slowly open inlet valve and allow the system to fill with water.

7. Close the down stream valve five minutes after all the air has been purged
from the system and plumbing. This flushes any fines out of the system.

8. Check for leaks and repair as required.

9. System is ready for use.

Conditions for Operation:

• Minimum pressure 15 PSI

• Maximum pressure 125 PSI

• Minimum operating temperature 34 F

• Maximum operating temperature 120 F

• Water pH range 6.0 to 9.0

• Maximum feed water hardness is 25 grains per gallon.

• Hydrogen sulfide, iron, and manganese pretreatment

required

• Maximum chlorine 3 ppm, de-chlorination recommended

• Oil and grease should not be present

• Warning - Do not exceed specified flow rates

• Residential systems are designed for intermittent flow, for

continuous flow use commercial systems

Top view with optional bypass

Inlet

Outlet