Installation Guide

SETTING MIXING VALVE WITH RECIRCULATING SYSTEM
MAINTENANCE
Periodic inspection and maintenance by a licensed plumber is required to insure proper and efficient performance of the unit. Frequent cleaning
and/or replacement of shuttle O-ring is required and recommended. Shuttle O-ring requires periodic lubrication using silicone based lubricant only.
PTFE or petroleum based lubricant may cause O-ring swelling.
REPAIR KIT INFORMATION
TROUBLE SHOOTING
Cold and Hot water inlet pressure differential Install pressure reducing valve or pressure
greater than 30 psid limiting device to maintain equal
and consistent pressures.
Shuttle assembly damaged or worn Replace with repair kit.
Setpoint adjustment at maximum setting Increase inlet water temperature setting
allowing valve to mix.
Hot water temperature above 180°F Adjust water heater temperature
Inlet check valves clogged or damaged Replace inlet check valves
Supply valves closed Check cold and hot water supply valves
Inlet check valves clogged or damaged Clean or replace
Strainers completely clogged Clean or replace
Loss of supply pres sure Check with licensed plumber
Cold water inlet check valve defective, clogged or Inspect, clean or replace cold water check
damaged and cold water pressure is less than valve
hot water supply pressure
Hot water inlet check valve defective, clogged or Inspect, clean or replace hot water check
damaged and hot water pressure is less than valve
cold water supply pressure
No flow
Hot water backing-up in cold water supply
Cold water backing-up in hot water supply
PROBLEM CAUSE SOLUTION
Hot water inlet temperature within 15°F of outlet mix
setpoint.
Increase hot water inlet to more than 15°F
above outlet setting.
Mixed temperature fluctuating or erratic
Mixed temperature will not adjust to desired
temperature
WARNING: FAILURE TO FOLLOW ABOVE INSTRUCTIONS COULD RESULT IN UNSAFE DISCHARGE TEMPERATURE, WHICH MAY
CAUSE INJURY OR DEATH.
CALIFORNIA PROP 65: WARNING: Cancer and Reproductive Harm - www.P65Warnings.ca.gov.
This product complies with U.S. Safe Drinking Water Act (SDWA). Suitable for potable water applications intended for human consumption.
I-9981-00 rev. B
MODEL NO. QTY DESCRIPTION
1 A179500 SPRING
1 E307800 FLOW MIXER
1 W434805 SHUTTLE SUB- ASSY
F326400 SHUTTLE
I637800 THERMOSTAT
D492300 O-RING, -024
1 I998100 IOM
PART NO.
MVBLF-RK
(34BLF300RK)
1) After installation is complete (refer to installation instructions), close and tag all fixtures not used in this procedure.
2) Turn off recirculating pump.
3) Open fixture/fixtures to flow greater than the minimum flow rate of the mixing valve. Tag open fixture/fixtures to prevent any possible
usage of untempered water.
4) Allow water to flow through the mixing valve until water temperature is stable. If necessary, re-adjust the valve according to
“ADJUSTMENT” instructions.
5) Once the temperature is set, start recirculating pump and allow the system to reach set temperature.
6) Measure water temperature downstream of the recirculating pump and adjust aquastat to shut-off the pump when the return water
exceed the set point by 2 °F. Set the aquastat to restart the pump when the return water drops 5 °F below set temperature.
7) Set the balancing valve in the full open position.
8) Close all fixtures and make sure no demand is allowed. The cold inlet temperature to the mixing valve should be warm.
9) Allow the system to run without demand for at least 30 minutes. In some cases, an increase in water temperature may occur during a
no load period. If this occurs, slowly regulate balancing valve until water temperature is back to the original set temperature.