Install Instructions
VC2, VC4, VC60, VC8
3 95C-10920—03
INSTALLATION
When Installing This Product...
1. Read these instructions carefully. Failure to follow them 
could damage the product or cause a hazardous condi-
tion.
2. Check the ratings given in the instructions and on the 
product to make sure the product is suitable for your 
application.
3. Installer must be a trained, experienced service techni-
cian.
4. Always conduct a thorough checkout when installation 
is completed.
5. While not necessary to remove the actuator from the 
body, it can be removed for ease of installation. The 
actuator can be installed in any of the four orientations 
to suit the most convenient wiring direction. Actuator 
latching mechanism works only when the lengths of the 
actuator and the valve body are parallel to each other.
6. An extra 1” (25 mm) head clearance is required to 
remove the actuator.
CAUTION
Disconnect power supply before connecting 
wiring to prevent electrical shock and equipment 
damage.
On 24V systems, never jumper the valve coil 
terminals, even temporarily. This may damage the 
thermostat.
PLUMBING
The valve may be plumbed in any angle, including vertical 
piping, but preferably not with the actuator below horizontal 
level of the body. Make sure there is enough room around the 
actuator for servicing or replacement
For use in diverting applications, the valve is installed with the 
flow water entering through bottom port AB, and diverting 
through end ports A or B. In mixing applications the valve is 
installed with inlet to A or B and outlet through AB. 
Mount the valve directly in the tube or pipe. Do not grip the 
actuator while making and tightening up plumbing 
connections. Either hold valve body in your hand or attach 
adjustable spanner (38 mm or 1-1/2") across hexagonal or flat 
faces on the valve body. 
If assembling valve train on a bench, take care not to deform 
body with vice. Do not place the raised "H" logo between the 
jaws of the vice. Excess jaw force can deform the body.
IMPORTANT
For trouble-free operation of the product, good instal-
lation practice must include initial system flushing, 
chemical water treatment, and the use of a 50 micron 
(preferably 5 micron) 10% side stream system fil-
ter(s). Remove all filter(s) before flushing. Limit flow 
through the filter to 5~10% of total system flow to 
prevent 'starving' the system. Ensure filter cartridge 
is changed frequently enough to prevent clogging. 
Put the VC actuator manual lever in the manual open 
or the fully open (down) position to allow initial sys-
tem flushing with the actuator mounted. This may be 
done without electrical hook-up. Alternatively, reus-
able flush caps, part # 272866B, may be purchased 
separately for use in initial flushing of dirty hydronic 
systems.
Do not use boiler additives, solder flux and wetted 
materials which are petroleum based or contain min-
eral oil, hydrocarbons, or ethylene glycol acetate. 
Compounds which can be used, with minimum 50% 
water dilution, are diethylene glycol, ethylene glycol, 
and propylene glycol (antifreeze solutions).
SWEAT MODELS
On sweat fitted valves, the cartridge is shipped loose to avoid 
being damaged during the solder operation.
1. Remove valve actuator from body and solder the con-
necting pipes in accordance with normal soldering prac-
tices.
2. After soldering and valve has cooled, remove cartridge 
assembly from plastic bag, insert into the valve body 
and tighten down with enclosed wrench until it bottoms 
out. DO NOT OVER TIGHTEN (maximum torque is 
40 in-lb). 
3. Replace valve actuator.
TO INSTALL ACTUATOR
Installation of the actuator does not require draining the 
system, provided the valve body and valve cartridge assembly 
remain in the pipeline. Wiring may be done either before or 
after the actuator is installed.
1. The actuator head is automatically latched to the valve. 
Align the coupling hole in the bottom of the actuator with 
the valve stem. Press the actuator down towards the 
body with moderate hand force and turn the actuator 
counter-clockwise by 1/8 turn (45 degrees) to line up the 
actuator with the piping. The latch will click when 
engaged. See Figure 2.
NOTE: The actuator can also be installed at right angles to 
the valve body but in this position the latch mecha-
nism will not engage.
2. Connect leadwires. See Figure 3 for flexible conduit 
installation with plenum-cable models.
Fig. 2. Latch Mechanism to detach Actuator








