Combustion Research Omega II, Installation, Operating, Maintenance And Parts Manual

Omega II

®

 Installation, Operation & Maintenance 

Combustion Research Corporation 

Page 33 

5.  The sensing probe detects the presence of the low fire 

flame and the control de-energizes the spark and the 
valve will remain open.  Check valve outlet and other 
downstream pipe connections with a soap solution. 

6.  Turn the thermostat to a low dial setting to open 

contacts.  The main gas flame should be extinguished. 

7.  For 100% shutoff check, set thermostat to low dial 

setting (system off).  Disconnect sensing probe lead at 
control terminal. 

8.  Turn thermostat to a high dial setting to energize spark 

ignition and valve.  The gas should ignite.  After 30 
seconds, the system should "lockout" and burner 
functions are off (no gas flow, no spark).  If the system 
does not go into "lockout," follow the installation 
instructions to replace the control.  Repeat the 100% 
shutoff check.  Note blower will not shut down when 
ignition "lockout" occurs. 

9.  Set thermostat again to a low dial setting (system off), 

connect probe lead to control terminal.  Set  thermostat 
to normal setting to put system back in service. 

CHECK SAFETY SHUTDOWN PERFORMANCE 

WARNING 

FIRE OR EXPLOSION HAZARD 

IMPROPER INSTALLATION, ADJUSTMENT, 
ALTERATION, SERVICE OR MAINTENANCE 
CAN CAUSE DEATH, SEVERE INJURY 
AND/OR PROPERTY DAMAGE.

Perform the safety shutdown test anytime work is done 
on a gas system

.

NOTE:  Read steps 1-7 below before starting safety 
shutdown or safety lockout tests for the ignition  module. 

1.  Turn gas supply off. 

2.  Set the thermostat or controller above room temperature 

to call for heat. 

3.  Watch for ignition spark immediately or following pre-

purge.  See ignition module specifications. 

4.  Time length of ignition operation.  See ignition module 

specifications. 

5.  After the module locks out, open gas control and ensure 

there is no gas flow to main burner. 

6.  Set the thermostat below room temperature and wait 

one minute. 

7.  Operate system through one complete cycle to ensure 

all controls operate properly. 

IGNITION CHECKOUT PROCEDURES 

A combination voltmeter and micro-ammeter with a DC 
micro-ammeter range setting of 0 to 10 micro-ampere is 
required.  Follow meter instructions for proper use.  TO 
CHECK AC VOLTAGES: 

1.  Set range selection switch to 150V AC before 

connecting leads. 

2.  Connect wire leads in parallel with voltage to be 

measured. 

3.  Read voltage on AC scale. 

TO CHECK CURRENT FROM FLAME SENSING 
PROBE:

1.  Set range selector switch to 10 micro-amperes before 

connecting leads. 

2.  Turn off power supply to ignition control. 

3.  Disconnect sensing probe cable from sensor terminal or 

ignition control. 

4.  Connect red (positive) meter lead to sensor terminal. 

5.  Connect black (negative) meter lead to probe cable. 

6.  Turn on electrical supply to system and cycle system 

through the thermostat. 

7.  After system has ignited, the meter should read 0.7 

micro-amperes or higher.  If less than 0.7 micro- 
amperes, the control may need to be replaced.  Check 
all wiring connections before replacing control. 

8.  Turn off supply voltage. 

9.  Disconnect meter from sensor terminal and probe cable. 

10. Reconnect probe cable to sensor terminal. 

11. Turn on supply voltage. 

IGNITOR / FLAME SENSOR 

0.10” Spark gap 

Flame sensor

!