DSI Integrated
Control Module
(Circuit Board) Trial
Troubleshooting
Flowchart
Trial for |
| Is there a | NO |
| Is there | YES |
Ignition |
| spark across gap at |
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| spark voltage at |
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Call for Heat |
| ignitor? |
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| control? |
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| YES |
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| NO |
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| Check wiring and/or | NO | Is there | YES |
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| 24VAC transformer |
| 24V |
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| output. |
| control? |
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Check high voltage wire continuity.
Replace control module.
Is there minimum | Is there | |
YES minimum flame current | ||
flame current at the flame | ||
sensor? | at the control | |
module? | ||
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YES | Does gas | NO |
| ignite? |
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YES | Replace control | YES Is gas flowing? NO |
| module. |
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| NO | NO |
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| YES |
| Check connections to | Check gas pressure and |
| YES |
|
Clean | Is the flame sensor | flame sensor or | supply voltage. If either YES | Is the ignitor | Is there | ||
flame |
| corroded? | moisture in bulkhead | are low, correct and | position correct in the | Replace gas valve. | 24VAC at the gas |
sensor. |
| gas flow? |
| valve? | |||
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| connector. | repeat startup. |
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NO
Is the sensor | YES |
located in flame |
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correctly? |
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| NO |
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| NO |
Replace flame | Reposition spark | Check wiring and | YES | Is there 24VAC from |
sesnsor. | ignitor. | connections to gas |
| gas valve output on control |
valve. |
| module to chassis? | ||
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|
NO | NO |
| |
Repositon flame | Replace ignition |
sensor. | control module. |
General Troubleshooting
PROBLEM | PROBABLECAUSE | REMEDY | ||
Venter motor will | 1. No power to unit. | 1. Turn on power; check supply fuses or main circuit breaker. | ||
not start | 2. No 24 volt power to integrated circuit board. | 2. Turn up thermostat; check control transformer output. | ||
| 3. | Integrated circuit board fuse blown. | 3. | Correct cause. Replace fuse (type ATC or ATO, 32VDC, 3A). |
| 4. | No power to venter motor. | 4. | Tighten connections at circuit board and/or motor terminals. |
| 5. | Integrated circuit board defective. | 5. | Replace intergrated circuit board. |
| 6. | Defective venter motor. | 6. | Replace venter motor. See Paragraph 32. |
Burner will | 1. Manual valve not open. | 1. Open manual valve. | ||
not light | 2. Air in the gas line. | 2. Bleed gas line (initial startup only). | ||
| 3. | Gas pressure too high or too low. | 3. | Supply pressure should be 5" - 14" w.c. for natural gas or 11" - 14" |
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| w.c. for propane gas. | |
| 4. | No Spark: | 4. |
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| a) Loose wire connections. | a) Be certain all wire connections are solid. | ||
| b) Transformer failure. | b) Be sure 24 volts is available. | ||
| c) Incorrect spark gap. | c) Maintain spark gap at 1/8". | ||
| d) Spark cable shorted to ground. | d) Replace worn or grounded spark cable. | ||
| e) Spark electrode shorted to ground. | e) Replace if ceramic spark electrode is cracked or grounded. | ||
| f) Burner not grounded. | f) Make certain integrated circuit board is grounded to ignitor. | ||
| g) Circuit board not grounded. | g) Make certain integrated circuit board is grounded to furnace chassis. | ||
| h.) Unit not properly grounded. | h.) Make certain unit is properly field grounded to earth ground and | ||
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| properly phased (L1 to hot lead L2 to neutral). | |
| i) Integrated circuit board fuse blown. | i) Correct cause. Replace fuse (type ATC or ATO, 32VDC, 3A). | ||
| j.) Faulty intergrated circuit board. | j) If 24 volt is available to the integrated circuit board and all other causes | ||
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| have been eliminated, replace board. | |
| 5. | Lockout device interrupting control circuit by above causes. 5. Reset lockout by interrupting control at the thermostat or main power. | ||
| 6. | Combustion air proving switch | 6. |
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| not closing. | a) Make sure unit is properly vented. | ||
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| b) Remove obstructions from vent. | |
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| c) Replace faulty tubing to pressure switch. | |
| 7. | Faulty combustion air proving switch. | 7. | Replace combustion air proving switch. |
| 8. | Main valve not operating. | 8. |
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| a) Defective valve. | a) If 24 volt is measured at the valve connections and valve remains | ||
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| closed, replace valve. | |
| b) Loose wire connections | b) Check and tighten all wiring connections. | ||
| 9. | Integrated circuit board does not power main valve. | 9. |
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| a) Loose wire connections. | a) Check and tighten all wiring connections. | ||
| b) Flame sensor grounded. | b) Be certain flame sensor lead is not grounded or insulation or ceramic is | ||
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| not cracked. Replace as required. | |
| c) Incorrect gas pressure. | c) Supply pressure should be 5" - 14" w.c. for natural gas or 11" - 14" | ||
| d) Cracked ceramic at sensor. | w.c. for propane gas. | ||
| d) Replace sensor. |
Form