Installation manual

7
ALL HEATERS BY THIS
MANUFACTURER HAVE
REDUNDANT GAS VALVES.
Heaters set for less than 700,000 BTU’s use a
combination gas valve. The combination gas valve
has redundant solenoids and a regulator built into one
body. Larger heaters use a regulator and two
separate solenoid valves. The redundant gas valves
shut gas flow off to the burner in case of a
malfunction, no call for heat, or power outage. They
are normally closed, and are energized by the Fireye
FSC. The regulator controls the gas pressure going
into the gas train from the supply line. The “high fire”
setting for the heater unit (maximum temperature
rise) is adjusted by the regulator before the two
redundant solenoid valves or on the combination gas
valve (whichever the case may be).
#1 Size
160° F
#2 Size
150° F
#3 Size
225° F
#4 Size
245° F
#5 Size
150° F
The following is a summary of a normal start for a direct fired gas heater:
• With the blower already running
ü
The summer-winter switch is set to winter
OR
ü
The outside air temperature falls below the setting of the outside air override
•
The FSC is energized and the following occurs:
ü
Indicates that it has power by turning on the “Opr Ctrl” light
ü
Verifies airflow and turns on the “Airflow” light
ü
Pauses 10 seconds to purge the air in the heater
ü
Begins Pilot Trial for Ignition and turns on the “PTFI” light
ü
The redundant gas solenoid valves are opened, the Honeywell spark igniter begins sparking and the UV
sensor watches for flame initiation
ü
When flame is established, the “PTFI” light turns off and the “Flame” light turns on
ü
The Maxitrol system is powered and the unit begins heating
ü
The FSC monitors the flame while the Maxitrol system adjusts to the selected temperature
•
The Maxitrol system checks the discharge air temperature (and the room temperature for the Maxitrol 44)
and regulates the gas going to the burner to satisfy the temperature setting.
•
The last light on the Fireye is the “Alarm” light. This will turn on when the Fireye determines an unsafe
condition, and won’t allow the unit to recycle for heat until it has been properly reset. Anytime the Fireye flame
safety has gone into “Alarm” mode, the problem must be diagnosed and corrected to avoid future lockouts
after resetting. To begin troubleshooting, or to reset the Fireye, the following procedure must be used (just
pushing the reset button does NOT reset the unit)
•
With the power to the unit
ü
Push the reset button on the Fireye
ü
Turn power off (the 5 Amp circuit breaker is convenient for this)
ü
Turn power back on and allow the heater to start up
Honeywell High Temperature Limit