C E N T R I F U G A L H E A T E R - C S A
Chief Industries, Inc. 800-359-7600 MAINTAINENCE - 416274
Page 41
a.
Use voltmeter and check continuity between terminals 5 and 6 on terminal block. If
there is no continuity, replace switch. (Verify that the vapor limit switch has had
sufficient time to cool and automatically reset).
8.
Air switch may be defective.
a.
With the fan running, check continuity across the air switch. If no continuity is present
and the fan is delivering air, the problem is in the air switch or in the venturi.
b.
Verify the screen on the venturi is not plugged. If the fan is working against 4" static
pressure or lower, the heater should operate.
9.
High limit may be closed.
a.
Use voltmeter to check for continuity between the two leads going to high limit channel.
(Terminal #1 on the terminal block and #3 on the start relay.)
b.
If there is no continuity, remove the sensor from the bin. Check the switch individually
by putting leads of voltmeter on the two screws that have wires attached. The switch
should not show continuity. Replace switch if defective. If switches are functional, the
limit wire is defective. Replace damaged wire.
10.
Flame sensing relay is not completing the circuit.
a.
Turn off switch to de-energize the circuit. Check the continuity of the contacts of the
relay. Check for continuity in the normally closed set of contacts (2 and 4, also 5 and 7).
A lack of continuity indicates a defective relay. Replace the relay.
b.
Supply power (115V and neutral) to the coil (terminals 1 and 8). Check power at the
normally open set of contacts (2 and 3, also 6 and 7). After power has been supplied to
the relay for 30 seconds, power should be present at the terminals. If not, replace the
relay.
11.
Purge delay may be defective.
a.
Turn off switch to de-energize the circuit. Check the continuity at the contacts of the
relay. Check for continuity in the normally closed set of contacts (2 and 4, also 5 and 7).
A lack of continuity indicates a defective relay. Replace the relay.
b.
Supply power (115v and neutral) to the coil (terminals 1 and 8). Check power at the
normally open set of contacts (2 and 3, also 6 and 7). After power has been supplied to
the relay for 30 seconds power should be present at the terminals. If not replace the
relay.
12.
Check all wires and connectors to verify they are functional and installed correctly.
a.
See wiring schematic for correct installation
Condition Specific Faults:
1.
Symptom: No ignition, Lack of ignition spark, Gas is present.
a.
Transformer is defective (power on).
i.
Take the cap holding the spark plug wire off and remove the spark plug wire
from the transformer. With the transformer energized, ground an insulated
