Fig. 1—Mounting and location guidelines.
DO NOT FORCE COLLAR OF MOUNTING FLANGE PAST STOP.
MOUNTING (See Fig. 1)
Follow the mounting instructions supplied by the fur-
nace, boiler, or burner manufacturer, if available, or use the
instructions provided below.
When replacing one of the controls listed above, iden-
tify each leadwire as it is removed from the old control by
marking the wire with the number of the RA116A terminal
to which it will be connected. Refer to Table 2 to translate
the old terminal identification to the new RA116A terminal
TABLE 2—IDENTIFYING TERMINALS FOR
on Old Control
1, LH, or HOT LINE
2, LG, or LINE
3, 4, M, or MOTOR
If the position of the old control was satisfactory, install
the new RA116A in the same location as the old one. Be
sure to insert the bimetal element the same distance into the
stack as the old element. If the old element was inserted
more than 5-1/2 inches [140 millimeters], also insert the
new RA116A 5-1/2 inches [140 millimeters] into the stack.
If the position of the old control was not satisfactory,
tightly close the old holes with a metal plate and follow
1. To determine location:
• Locate the RA116A between the boiler or furnace
and draft regulator.
• Locate the RA116A as near as possible to the
boiler or furnace.
• If mounting in an elbow, locate the element near
the outer curve where the hottest gases flow.
• Do not locate the element where the temperature
can exceed 1000° F [556° C].
2. Cut a 1-3/8 inch [35 millimeter] hole in the stack at
the desired location .
CUT 1-3/8 INCH [35 MM]
HOLE IN STACK
TIGHTEN LOCK SCREW
INSERT BIMETAL ELEMENT IN CENTER OF
STACK IN DIRECT PATH OF HOT FLUE GASES
on New RA116A
DRILL HOLES AND FASTEN
FLANGE WITH SCREWS FURNISHED
3. Drill two holes and fasten the mounting flange using
the screws provided. The flange should snugly fit the
mounting surface, but it can be bent to fit a varying radius
stack or flattened to fit a flat surface. Do not force the collar
or mounting flange past the stop.
4. Insert the bimetal element at the center of the stack
in the direct path of the hottest flue gasses.
5. Tighten the lock screw.
All wiring must comply with applicable codes and
1. Connect the leadwires to the RA116A terminals as
2. Connect the thermostat to the RA116A as shown in
Figs. 2 or 3.
Startup and Checkout
CAN CAUSE SEVERE BURNS
Be sure the combustion chamber is free of oil or
oil vapor before starting the system.
STEP THE PYROSTAT DETECTOR CONTACTS
The detector contacts are actuated by a friction clutch
that is mounted on a rod connected directly to the heat-
actuated element. Occasionally, this clutch becomes out of
step after a long period of idleness. To place the clutch and
the contacts in step:
1. Remove the cover.
2. Pull the lever forward 1/4 inch (Fig. 4).
3. Slowly release the lever.
4. Replace the cover.
START THE SYSTEM
1. Be sure the Pyrostat detectors are in step.
2. Push in and release the safety switch reset button.