L.B. White I-40 Infraconic Ignition - Manual (Page 15)

HOSE
ADAPTER
FLATS
VALVE BODY
ADAPTER NUT
ADAPTER
THERMOSTATIC HEAD
BYPASS ORIFICE
Individual Control Heaters
The bypass orifice is located in the valve body of the
individual controlled heaters. Its purpose is to supply low
pressure gas to the inner combustion cone when heat
demand is satisfied.
The orifice may become plugged with dirt after significant
heater use. Symptoms of a plugged orifice are:
-- Inner cone goes out when thermostatic head cycles
heater back to low heat.
-- Flame back flashing through air intake at injector
body.
Refer to the following instructions:
1. Apply wrenches to the flats of the valve body and the
adapter nut. See Fig. 13.
2. Loosen the adapter nut at the outlet of the valve
body.
3. Pull the control assembly with adapter and adapter
nut from the valve body. See Fig. 13.
4. Using a 3/16 in. nut driver, remove the orifice from
valve body. See Fig. 14. Clean or replace if
necessary. At reinstallation, do not overtighten as
thread damage may occur.
FIG. 13
FIG. 14
1155
LOW FIRE ORIFICE
THERMOSTATIC
HEAD
BYPASS ORIFICE
THERMOSTATIC
HEAD
SAFETY GAS CONTROL VALVE
1. Disconnect the gas hose.
2. Loosen the gas supply tube compression nut and
swing the tube away from the safety control valve.
3. Remove the thermocouple from the safety control
valve.
4. Loosen the screw on the injector body.
5. Remove the safety gas control valve with injector tube
from the heater.
6. Remove the injector tube.
FIG. 12
PILOT SAFETY VALVE
SCREW
BYPASS GAS SUPPLY TUBE
THERMOCOUPLE
INJECTOR BODY
INJECTOR TUBE
SAFETY CONTROL VALVE
GAS SUPPLY TUBE