Troubleshooting Flow Chart (Furnaces Equipped With Time Delay Relay); Trouble Shooting Guide - Suburban SFV-30 Service Training Manual

SUBURBAN RV FURNACES with TIME DELAY
Thermostat Closes
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YES
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Approximately 10-20 seconds
Blower is operating
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YES
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After fifteen (15) seconds the module
creates spark and opens valve
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YES
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Spark occurs for approximately seven
(7) seconds and main burner flame
establishes
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YES
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Thermostat opens and the time delay
operates the fan for the cool down cycle
YES
SYSTEM OK

TrOublE ShOOTinG GuiDE

12 VDC HEATING SECTION
Check thermostat wire connections,
- NO →
contact points and the heat anticipator.
Check 12VDC at BLuE wire, check the
amp draw to the thermostat.
Check components amperage.
Check for 12VDC at Furnace
Check fuse or circuit breaker
Check for 12VDC at time delay relay
- NO → and for 12VDC to RED wire leading to
Check GROuND wire on terminal block
Check for 12VDC between RED and
- NO →
YELLOW wires at the module board
Check for 12VDC at Limit Switch,
Check for 12VDC at Sail Switch,
- NO →
No Spark at the Electrode
Check for 12VDC at
Gas Solenoid Valve
Did the Gas Valve open?
Check for restriction in combustion air
intake (wasps, insects, etc.)
is flame established?
- NO → Replace the Time Delay Relay
- YES →
No
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- YES →
No
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Check for shorts.
- YES →
YES
YES
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YES
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the motor.
YES
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- YES →
No
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- YES →
on both sides
No
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- YES →
on both sides
YES
YES
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YES
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No
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30
Clean points, secure loose connections,
replace thermostat if anticipator is
shorted.
Replace Thermostat.
Repair or replace connection or parts
with higher than normal amp draw.
- NO → Check ON/OFF Switch on Furnace
- NO → Replace fuse/Reset Breaker
- NO → Replace the Time Delay Relay
- NO → Replace the motor
Check plug connection tot he Module-
Electrode and Wire-Spark gap 1/8"
between probe and ground
Replace the Sail Switch
Replace the Limit Switch
- NO →
Replace the Module
- NO → Replace the Module
Check gas pressure at the manifold or
- NO →
for restrictions in the burner orifice
No
▼
Replace the gas valve
Check flame contact to electrode.
- NO →
Flame should be hard blue
NOTE: On some models, Sail
Switch is before Limit Switch