Overview
The Watts U-M311 elapsed time monitor is a smart and
connected system monitor that automatically notifies the user
when media replacement is needed for their OneFlow system.
The recommended life span for the media within these systems
is 3 years. Upon reaching a 3 year service life, the U-M311 will
send an automatic notification by email or text based on user
preference. Water usage volumes and media life remaining can
also be viewed on the monitor's color touch screen. Should you
have any further questions, please call our customer service
(978) 689-6066 or your Watts representative.
Some assembly is required to install the U-M311 elapsed time
monitor and inline flow meter within an existing system installa-
tion for OneFlow OFRES-K and OFCOM-EK systems. Specific
system manuals for OneFlow models OFRES-K and OFCOM-EK
can be located at watts.com
Please review Operational Parameters and Feed Water
Guidelines sections below and in the specific system manuals to
ensure compatibility and performance.
Installation Precautions
• Do not let the system freeze. Damage to the product
may result.
• Install the system in a place where water damage is least
likely to occur if a leak develops.
• System is intended to be installed indoors.
• Do not install if your water lines are susceptible to water
hammer. Correct water hammer issues first before
system installation.
• Observe all local plumbing and building codes when
installing the product.
• If making a soldered copper installation, do all sweat
soldering before connecting pipes to the product. Torch
heat will damage plastic parts.
• When turning threaded pipe fittings onto plastic fittings, use
care not to cross-thread.
• Use PTFE tape on all external pipe threads. Do not use pipe
joint compound.
• The full weight of the plumbing must be supported by pipe
hangers or other means.
• Locate any hidden electrical wires or plumbing before drilling
into wall to mount monitor.
• Product must plug into an uninterrupted GFCI protected
power outlet
• The product must connect to a 2.4GHz Wi-Fi network for
the automatic notifications to function.
Operational Parameters and
Feed Water Guidelines
NOTICE
Installation must comply with state and local plumbing regulations.
Please review operating pressures, temperatures and water
chemistry limitations to ensure compatibility.
pH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.5 to 8.5
Min/Max Water Pressure* . . . 25psi to 90psi / 1.7 bar to 6.2 bar
Min/Max Water Temperature . . . . . 34°F to 100°F / 1°C to 38°C
Free Chlorine (maximum) . . . . . . . . . . . . . . . . . . . . . . . 2.0 mg/L
Iron (maximum) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.3 mg/L
Manganese (maximum) . . . . . . . . . . . . . . . . . . . . . . . 0.05 mg/L
Copper (maximum) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.3 ppm
Total Phosphates . . . . . . . . . . . . . . . . . . . . . . . . . . . . <3.0 ppm
Silica (maximum). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 ppm
TDS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <1500 mg/L
Oil and H2S . . . . . . . . . . . Must be removed prior to the system
Turbidity/Sediment . . . . . . . . . Water known to have heavy loads
Electrical Requirements . . . . . . . . . . . . . . 115V/60Hz USA Plug
Min/Max Ambient Temperature . . . 34°F to 120°F / 1°C to 48°C
Maximum Humidity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75%
Power Supply Input Voltage/Frequency . . . . . . 115 VAC / 60Hz
Power Supply Output Voltage. . . . . . . . . . . . . . . . . . . . . 12 VDC
Power Supply Output Current . . . . . . . . . . . . . . . . . . . .4 amps
Maximum Altitude . . . . . . . . . . . . . 2,000 meters above sea level
Wi-Fi Signal Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.4GHz
Notification Interval . . . . . . . . . . . . . . Optional: @50%/90%/95%
Flow Meter Connection Size/Type . . . . . . . . . . . . 1" x 1" MNPT
Maximum Flow Rate** . . . . . . . . . . . . . . . . . . . . . . . . . 26 GPM
* Published maximum water pressure of 90psi/6.2 bar is for
operation with OFRES-K Series systems. When used with
OFCOM-EK Series systems maximum allowable water
pressure is 100psi/6.9 bar.
** Maximum flow rate shown is for the meter alone. For all
OneFlow system maximum flow rates see system specification
documents ES-OFRES-K or ES-OFCOM-EK for maximum flow
rates specific to your model.
Feed water guidelines above include product operation with
Watts OneFlow media. Please refer to the system manual spe-
cific for your system model number for additional information.
For all other guideline information please contact your Watts
representative. Water that does not meet the above guidelines
will require additional pre-treatment.
4
of dirt and debris should be
prefiltered prior to system
of 3 year capacity used
Mandatory: @ 100% of
3 year capacity used