Single-Stage
RTUgas valve
_. On/Off
_'--Switch
Two-Stage 300k BTU/Hr
RTU gas valve Two-Stage
4-- sCni/tOff
C08469
Fig. 9 - Single- and Two-Stage RTU Gas Valves
Step 6 1 Move the RTU gas valve on/off switch to
the ON position.
Step 7 1 Replace the gas component access panel.
C08490
Fig. 10 - Replacing the Gas Component Access Panel
Step 8 1 Remove disconnect lockout tag and restore
power to the unit by switching the RTU main
disconnect to ON.
C07336
Fig. 11 - RTU Main Disconnect - Electrical Supply
Step 9 1 Turn on the gas supply by opening the gas
supply shut-off valve.
Fig. 12 - Gas Supply Shut Off Valve
C07337
Fig. 13 - Thermostat/Unit Controller
C07381
FIRE, EXPLOSION HAZARD
Failure to follow this warning could result in personal
injury, death or property damage.
If the main burners fail to light, or the blower fails to
come on, shut down gas heating section and call your
dealer for service.
TO SHUT UNIT OFF
FIRE, EXPLOSION HAZARD
Failure to follow this warning could result in personal
injury, death and/or property damage.
1. Turn off gas supply by closing the gas line supply
valve. Then, turn off the electrical power supply to the
unit by switching the diseonnect to off: Install lockout
tag before servicing or performing maintenance.
2. Do not turn off the electrical power to unit
without first turning off the gas supply.
Should overheating occur, or the gas supply fail to shut
oft'. shut off the gas valve in the unit (by moving on/off
switch to off) before shutting off the electrical supply.
Step 1 1 Set room thermostat/unit controller heat
setpoint to the lowest temperature setting and set the
SYSTEM switch to OFF.
Step 10 1 To start unit, set room thermostat/unit
controller heat setpoint to slightly above room
temperature. The induced-draft combustion air fan will
start. The RTU gas valve will open and main burners
should ignite within 5 seconds. If the burners do not
light, there is a 22-second delay. Burners will attempt
to ignite within 5-seconds. Each time the burner fails to
light, the 22-second time delay is repeated. If the
burner does not light within 15 minutes, the unit will
lockout the gas heat. To reset after a lockout, turn off
the main electrical supply to the unit by switching the
RTU main disconnect to OFF for a minimum of five
seconds. Repeat Steps 1-10. If burners still do not light,
call for service.
Step 11 1 Set the room thermostat/unit controller
heating setpoint to desired temperature setting.
C07381
Fig. 14 - Thermostat/Unit Controller
Step 2 1 Turn off gas supply by closing the gas
supply shut-off valve (external to RTU unit). See Fig.
3 or Fig. 4 (depending on the size of the unit) for
location.
Fig. 15 - Gas Supply Shut Off Valve
C07330
To Next Page
Loading...
