Apollo Conbraco 34BLF Installation Manual

MODEL “MVBLF” (34BLF310 SERIES)

MULTI-PURPOSE THERMOSTATIC MIXING VALVE

INSTALLATION

1. Unit must be installed by a licensed plumber/contractor in
accordance with these instructions and state and local
plumbing codes.

2. Proper piping alignment must be observed.

3. Flush all piping thoroughly before installation.

4. Mount the unit so that it is accessible for adjustment, cleaning
and service.

5. Adequate mounting support is recommended.

6. The unit can be installed in any orientation. Make sure that cold
water supply be connected to port “C”, hot water supply to port
“H”, and mixed water discharge to port “M”.

7. Cure times for CPVC joints shall be as recommended by the
adhesive manufacturer or 1 hour minimum, whichever is
greater. Exposure to temperature above 100 °F may require
extended curing times.

8. MAKE SURE THAT WASHER-STRAINER IS ORIENTED TO
ACHIEVE FLAT CONTACT WITH END FITTINGS.

TYPICAL INSTALLATION

NO RECIRCULATION SYSTEM

- FLOW DIRECTION

- THERMAL EXPANSION
RELIEF VALVE OR TANK

- PRV

- CHECK VALVE

- BALANCING VALVE

- CIRCULATOR/PUMP

- TEMPERATURE GAUGE

COLD WATE R
INLET

HEAT
SOURCE

BOILER,
WATER
HEATER,
ETC.

H

HC

HEAT
TRAP

MIXING
VALVE

M

ASSE 1017, 1070 & 1069

The thermostatic element which is positioned in the mixing chamber is
connected to an independently seated, balanced and spring-loaded
shuttle/piston, which moves up and down in response to the expansion
and contraction of the element. The spring force acting against the
bottom side of the shuttle will enable the hot inlet port to be normally
open, and the cold inlet port to be normally closed at no flow condition.
When flow demand starts, the thermostatic element will sense the hot
water temperature first, and will immediately expand to allow the shuttle
to move down. This movement decreases the opening area of the hot
water supply, and at the same time increases the opening of the cold
water until certain outlet temperature is maintained. The mechanical
balance of the forces in the shuttle and the sensitivity of the element
determines the proper proportion of incoming hot or cold water to
maintain required outlet temperature. In the event of complete failure of
the cold water supply, the ensuing expansion of the element shuts-off
the hot water supply.

ADJUSTMENT

For optimum performance, it is imperative that the hot water inlet

TYPICAL INSTALLATION

WITH RECIRCULATION SYSTEM

MIXING
VALVE

H

HC

HEAT
TRAP

C

MIX TEMP
FIXTURES

COLD WATE R
INLET

HEAT
SOURCE

BOILER,
WATER
HEATER,
ETC.

HIGH TEMP.

FIXTURES

C

AQUASTAT

MIX TEMP
FIXTURES

M

OPERATION

The Apollo “MVB” Series are designed to mix and regulate the amount
of cold and hot water to produce a comfortable and safe outlet
temperature at a predetermined setting, either from the “point of source”
or “point of use” application for single or multiple fixtures.

SCREW

NAMEPLATE

HANDLE

LIMIT STOP

SET SCREW

STEM RETAINER

SHUTTLE/PISTON

THERMOSTAT

FLOW MIXER

INLET

SPRING

CHECK VALVE (2)

STRAINER

WASHER (2)

UNION
NUT (3)

TAILPIECE (3)

RECIRCULATION

LOOP

temperature has a minimum of 15 °F above the desired outlet
temperature. The unit is equipped with a maximum temperature limit
stop and handle locking mechanism to prevent inadvertent adjustment
of the outlet temperature above 120 °F.

1) After the unit is completely installed, turn on the cold water
supply. It is recommended to open the cold side first to avoid
sudden temperature increase in the mixing chamber.

2) When the unit is at no flow condition and pressurized, check
Open end-fixture to establish flow. Observe lock-out/tag-out
procedures when unit is remotely installed from end-fixture.

MIXED TEMPERATURE ADJUSTMENT

1) Remove the handle screw, nameplate and handle.

2) Loosen set screw (1/16” allen wrench) located on the stem
retainer and loosen limit stop (13/16” hex).

3) Slide handle to engage stem and approximately ¼” above
retainer spline.

NOTE: Adjustment cannot be made if the handle and retainer
spline are engaged.

TEMPERATURE LIMIT STOP ADJUSTMENT

1) Once the mixed temperature is adjusted to a desired setting
(not exceeding 120 °F), tighten the limit stop by hand until it
stops against the stem. Do not over-tighten.

2) Tighten set screw to lock the limit stop.

3) In some conditions, the outlet temperature setting is adjusted
above 120 °F. This can be done by loosening the 1/16” set
screw to relieve the lock to the limit stop. Loosen limit stop and
make adjustment to desired setting. Once temperature
stabilized, tighten limit stop and lock set screw.

SETTING MIXING VALVE WITH RECIRCULATING SYSTEM

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.

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

MODEL NO. QTY DESCRIPTION

MVBLF-RK

(34BLF300RK)

PART NO.

1 A179500 SPRING
1 E307800 FLOW MIXER
1 W434805 SHUTTLE SUB- ASSY

F326400 SHUTTLE
I637800 THERMOSTAT
D492300 O-RING, -024

1 I998100 IOM

TROUBLE SHOOTING

PROBLEM CAUSE SOLUTION

Cold and Hot water inlet pres s ure differential Install pressu re reducing valve or pres s ure
greater than 30 ps id limiting device to maintain equal

Mixed temperature fluctuating or erratic

Mixed temperature will not adjust to desired

temperature

No flow

Hot water backing-up in cold water supply

Cold water backing-up in hot water supply

Shuttle as s embly damaged or worn Replace with repair kit.
Setpoint adjustment at maximum setting Increas e inlet water temperature setting

Hot water inlet temperature within 15°F of outlet mix
setpoint.

Hot water tem perature above 180°F Adjust water heater temperature
Inlet check valves clogged or dam aged Replace inlet check valves
Supply valves clos ed Check cold and hot water s upply valves
Inlet check valves clogged or dam aged Clea n or replace
Strainers completely clogged Clea n or replace
Los s of supply press ure Check with licens ed plum ber
Cold water inlet check valve defective, clogged or Insp ect, clean or replace cold water check
dam aged and cold water pressure is less than valve
hot water s upply pressure
Hot water inlet check valve defective, clogged or Insp ect, clean or replace hot water check
dam aged and hot water pres sure is less than valve
cold water supply press ure

and consis tent pressures .

allowing valve to mix.
Increas e hot water inlet to more than 15°F
above outlet setting.

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