Raypak 503-2003 - Manual (Page 39)

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28. When burner flame is rectified, the heater will
operate based on the electronic operating control.
In the event of an ignition lockout, the ignition
module sends a signal to pin P4-12 (ignition lock-
out) of the UDB board.
29. When the CFH is satisfied, the heater will return to
a standby condition awaiting the next CFH.
Ignition Module
When additional heat is needed, the combustion air
blower starts to purge air from the combustion cham-
ber for 15 seconds. On proof-of-air flow, the
air-proving switch closes and the igniter is energized.
To ensure safe operation, the gas valve cannot open
until the igniter is verified. The main burner is automat-
ically lit when the device is powered and pre-purged.
The heater performs its own safety check and opens
the main valve only after the igniter is proven to be
capable of ignition. The standard single-try ignition
module will lock out after failing to light one time. To
reset it, press and release the small, recessed black
push button located inside of the cut-out on the lower
right-hand corner of the ignition module case. Turning
off the power to the heater WILL NOT reset the
ignition module.
Fig. 35: Ignition Module
The optional ignition module will attempt to light three
times before locking out. To reset it, turn off power to
the heater, wait 30 seconds and re-apply power.
Table P: Ignition Module Diagnostic LED Flash Codes
Code Condition
On System OK; No faults present
Off Possible control fault; Check power
1 Flash Low air
2 Flashes
Flame in combustion chamber;
No call for heat
3 Flashes Ignition lockout
4 Flashes Low HSI current
5 Flashes Low 24 VAC
6 Flashes Internal fault; Replace control
High Limit—Manual Reset
This heater is equipped with a fixed setting manual re-
set high limit temperature device as standard or it may
have an optional adjustable setting manual reset high
temperature device.
The fixed setting manual reset high limit is located on
the In/Out header of the heat exchanger on the right
side of the heater (accessible through the front door
for reset as necessary).
The optional adjustable manual reset high limit is lo-
cated inside the heater junction box. Push the reset
button and adjust the setting to approx. 40°F (20°C)
above desired outlet temperature.
Fig. 36: High Limit (Manual Reset)