32
(TR250 and TR400 Models)
Flame Sensor
Air Box
Blower
Ignition Control
Board
Transformer
Keypad
Blower Vacuum
Switch
Fuse Board
Gas Valve
Sight Glass
Igniter
Access Panel
Gas Manifold
Figure 21: Location of Components
GENERAL:
Some of the following procedures will require the heater to be operating. Full lighting and shutdown instruc-
tions are included on the lighting and operating label affi xed to the inside of the front access panel. The heater
automatically lights in response to a call for heat, and automatically shuts down when that call for heat is satisfi ed.
Water must be fl owing through the heater during operation. Check that the pump is operating and the
system is fi lled with water and purged of all air prior to starting the heater.
GAS LINE TESTING:
The appliance and its gas connection must be leak tested before placing the appliance in operation. The
heater and its individual shutoff valve must be disconnected from the gas supply during any pressure testing
of that system at test pressure in excess of ½ psig (3.45 kPa). The heater must be isolated from the gas sup-
ply piping system by closing its individual manual shutoff valve during any pressure testing of the gas supply
piping system at test pressure equal to or less than ½ psig (3.45 kPa).
Gas supply line must be capped when not connected. After pressure testing, reconnect the gas piping to the
gas valve. Turn gas supply “ON” and test all pipe and tubing joints for leaks. Use a soap and water solution.
WARNING: EXPLOSIVE HAZARD
. The use of an open fl ame to check for gas
leaks could cause an explosion resulting in severe injury and/ or death. Shut off gas
and fi x even the smallest leak right away. Be sure to leak test the heater gas manifold
fi ttings using the above procedure once the heater is in operation.
SECTION III. INSTALLER CHECK-OUT AND START-UP