Greenheck Fan 470654 manual Heater Does Not Operate Direct Spark

Troubleshooting

Heater Does Not Operate (Direct Spark)

Does not attempt to light (No visible spark)

24 VAC between

terminals W1 and X?

Yes

24 VAC between

terminals 22 and 21?

Yes

24 VAC between

terminals 23 and 21?

Yes

24 VAC between

terminals 24 and 21?

Yes

24 VAC between

terminals 26 and 21?

Yes

Continuity between terminals 26 and 27?

Yes

No

No

No

No

No

No

Heat switch (S4) off.

Turn heat switch (S4) on.

Heat switch not wired.

Wire heat switch (S4).

Main transformer (TR2) defective.

Replace transformer.

(Optional) inlet air sensor (TS4) holding. Adjust TS4 setting.

Reference: Start-Up - Blower, Set-Up Optional Components, pg. 15

Heat relay (RH) defective.

Replace heat relay (RH).

High limit (HLC1) tripped.

Reset, replace high limit (HLC1).

Check on cause of control loss.

(Optional) high/low gas pressure switch(es)

(PS3 and PS4) tripped.

Correct gas pressure and reset.

Reference: Start-Up - Direct Gas, Check the Pilot Gas Pressure, pg. 15

Airflow switch (PS2) holding for proper airflow.

Correct airflow across burner.

Reference: Start-Up - Direct Gas,

Check the Optional High and Low Gas Pressure Switches, pg. 15

At this time the heater should attempt to light.

Model VSU Make-Up Air 29

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