Electronic Ignition Models - Atwood 79 Series Service Manual

Guides are only intended for use on Atwood
Atwood ® training. This guide should be used in conjunction with the appropriate Instruction Manual provided with the
product and any applicable Industry Standards. This is not intended to be a complete list. Please direct questions
concerning service of Atwood
CAUSE
BURNER FAILS TO IGNITE AND - BLOWER FAILS TO RUN
No electrical power to the furnace
Thermostat defective
Thermostat wires broken or shorted
Current overload protector device
Defective or tripped (circuit breaker).
Blower relay defective
Wire off motor
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Wire off relay
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Improper ground
--------------------------------
Blower motor defective
BLOWER RUNS - BUT FAILS TO IGNITE
Low Voltage/High Voltage
Gas pressure incorrect
Furnace grounding wires not secure
Air intake restricted
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12 volt polarity reversed
Motor running slow
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Exhaust blocked
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Combustion air wheel loose
Sail switch defective or wire off
Limit switch defective or wire off
Edge connector on circuit board dirty
Circuit Board defective
Gas valve defective
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Main burner orifice blocked
High tension lead wire defective
Electrode out of adjustment
Electrode defective
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Obstructed burner head
BURNER IGNITES BUT IGNITION SYSTEM "LOCKS OUT" AND TURNS BURNER OFF
Low gas pressure
--------------------------------
Exhaust blocked
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Combustion air wheel loose
Electrodes out of adjustment
Electrode defective
------------------------------
Circuit Board defective
Flame sensor wire between electrode
and circuit board defective
Air leakage at gaskets
Defective heat exchanger
® products by service technicians who have successfully completed
® products to 800-825-4328 option 5 before proceeding.
Reconnect or replace power source.*
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Replace thermostat
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Replace wire or wires*
--------
Reset circuit breaker. Check amp draw from motor
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According to furnace's specifications.
------
Replace relay
--------------------------
Reconnect wire
Reconnect wire
Clean and secure grounds*
Replace motor
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Correct Power Supply*
----------------------
Set pressure to a minimum of 11˝ W.C. with all appliances running.
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(Replace regulator if not obtainable).*
Clean and secure grounds established*
--------
Clean air intake.*
Correct polarity*
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Check voltage first. If 12 VDC while running, replace motor.
Clean exhaust.*
Reposition and tighten.
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Reconnect wire or replace.
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Reconnect wire or replace.
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Clean with pencil eraser*
------
Clean plug contacts. If still defective, replace. (check on board tester
--------------------------
when possible).
Replace valve or valve coil, depending on problem encountered.
Clean main burner orifice or replace.
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Replace wire
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Adjust electrode (take care not to damage porcelain).
------------------
Replace
Clean burner head*
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Set pressure to a minimum of 11˝ W.C. with all appliances running.
Replace regulator if not obtainable.*
Clean exhaust.*
Reposition wheel and tighten
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Adjust electrode according to furnace specifications.
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Replace electrode.
Clean plug contacts. If still defective, replace. (Check on board tester
--------------------------
when possible).
Replace wire
------
Replace gasket
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Replace heat exchanger
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*indicates NOT covered under warranty.
FURNACE -Electronic Ignition Model
TROUBLE SHOOTING GUIDE
SOLUTION
30
30
Effective: 8/10/98
continued backside