Installation & Service Manual
8 Maintenance
Figure
TRANSITION BOX SCREWS
Figure 8-6_Adjusting the air shutter
DECREASE
AIR PRESSURE
INCREASE AIR
PRESSURE
Servicing a hot surface igniter and ignition module
This unit uses a proven hot surface ignition module and a hot surface igniter. The hot surface ignition module is not repairable. Any modification or repairs will invalidate the warranty.
WARNING Do not attempt to repair a faulty hot surface igniter or ignition module. Any
modification or repairs may create hazardous conditions that result in property damage, personal injury, fire, explosion and/or toxic gases.
A faulty hot surface igniter or ignition module must be replaced with an identical part. A specification igniter and ignition module for this specific unit is available from your local distributor. Do not use general purpose field replacement ignition modules or igniters.
Ignition system checkout
1.Turn off gas supply to unit.
2.Turn electric power on.
3.Adjust the set point on the temperature control to a setting above water temperature or to the highest safe setting.
4.The igniter will cycle on trial for ignition.
5.The ignition module will lock out and turn the alarm light on.
6.Adjust the Set Point Differential and
7.Turn on gas supply.
8.Press the module reset button to reset the ignition module. This is a red button beside the ignition module or on the diagnostic panel on the
9.If ignition system fails to operate properly, repair work must be performed by a qualified service person or installer.
Sequence of operation
Overview
This sequence of operation can be considered the order of events in sequential order that occur after the appliance has received a call for heat. The process begins with 120VAC power entering the appliance and ends with the appliance going into an idle state after completion of a successful call for heat.
Note: The following descriptions do not include remotely connected devices that may be connected to the appliance. Refer to the wiring diagram for actual point to point wiring connections that show power delivery.
1.The POWER switch is placed in the “ON” position.
2.120VACpowerissuppliedtothecontroltransformeralong with L1 and F1 on the ignition module.
3.24VAC is supplied to the electronic temperature control, the ignition module and the adjustable high limit control.
4.24VAC is then supplied to the auxiliary limit control (if equipped).
5.If equipped, 24VAC is supplied to a low water
6.24VAC is supplied to the continuous alarm terminals A1 and A2 and then to the remote stage one terminal strip, 1C and 1NO.
7.24VAC is supplied to the electronic temperature control.
8.The electronic temperature control then calls for heat.
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