L.B. White I-17 Infraconic - Manual (Page 16)

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The following service instructions apply to individual
control or zone control heaters.
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The head assembly includes the adjustable
thermostatic head, capillary and sensor. The part
numbers for the thermostatic heads are:
-- Zone panel head: Part No. - 09416
w/ 26 ft. capillary
-- Individual control head: Part No. - 09415
w/ 6 ½ ft. capillary
During normal operation, the thermostatic head gradually
increases or decreases force against the modulating valve
pin to allow more or less gas pressure to the combustion
cones.
If the thermostatic head is set to a lower temperature but the
heat output from the combustion cones does not decrease,
refer to the following.:
-- Loosen the attachment knob located at the
thermostatic head and valve body so the valve
pin is exposed. See Fig.15.
-- Using a tool such as the flat of a standard
screwdriver, firmly but gradually push down on
the pin of the modulating valve.
-- If the heat does not decrease or you must use
significant pressure to force the pin, the valve is
sticking and needs replacement. Ensure flow
arrow on valve follows gas flow.
-- If the heat does decrease when the pin is pushed,
the thermostatic head is defective. The head is
available only with capillary with sensor.
FIG. 15
The attachment knob at the head must be securely
threaded onto the valve body, otherwise temperature
sensing will be affected.
The head’s sensor and capillary must be positioned above
animal height to avoid contact and subsequent damage by
livestock.
16
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Orifice sizes are stamped on the flat of orifice hex,
indicating size in millimeters. (Example: 44 is 0.44 mm
for LP primary orifice.) See Fig.17.
Size
Secondary (upper orifice, high heat)
LP- 44
NG- 61
Primary (lower orifice minimum to mid heat)
LP- 44
NG- 52
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If orifices are reversed combustion characteristics of the
heater will change on low fire.
1. Loosen the thermocouple nut at the safety control valve,
and remove the auto reset’s retaining screw and clip.
See Fig.16.
FIG. 16
2. Pull the air housing from the venturi tube to allow
access to orifices.
3. Using a 6 mm hex nut driver, remove the orifice. Clean
or replace if needed.
4. When reinstalling, do not overtighten as thread damage
may occur.
FIG. 17
BURNER ORIFICES
THERMOSTATIC HEAD and MODULATING VALVE
Individual Control Heaters and
Modulating Zone Panels
AIR HOUSING VIEWED FROM ORIFICE END
VENTURI TUBE
AIR HOUSING
RETAINING CLIP AND SCREW
LOOSEN THERMOCOUPLE NUT CONNECTED TO
SAFETY CONTROL VALVE
SECONDARY
ORIFICE
PRIMARY
ORIFICE
THERMOSTATIC
HEAD
ATTACHMENT KNOB
VALVE PIN
MODULATING
VALVE