Troubleshooting; Ignition And Call For Low Fire With Two-Stage Thermostat - Lennox G71MPP-36B-070 Installation Instructions Manual

IGNITION AND CALL FOR LOW FIRE WITH TWO-STAGE
THERMOSTAT
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A
T
L
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G
H
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0
F
F
_ [ Safety ]q
Check
Verify There ]
Is No Main Burner
Flame
YES
.. [De-Energ,ze
Circuit NO--I_- Gas Valve
i
YES
Indoor blower OFF After
Heat OFF Delay YES
Inducer On NO GaoVa,ve j, {100°,orate O._100°,o_
r_:::_:_ B
L s_eed/ "_ _o_,o_
Air Inducer
On (100% r soft Lockout:
rate speed) YES L Error Code
Flashes
Indoor Blower
ON (7O%)
[
YES
NO
__ i
YES
f
Combustion Air
Inducer ON at 70%
Rate Speed
No-[Pre_GtSo_,r
YES I
t
I Pre-Purge
I
-- 15 Seconds ,
i
-I ,onitorON I"
20 Second_
i
I Gas Valve Energized I
I
L Interpurge (15 Seconds) I
T
_ No
I Ignition Trial Begin_ Indoor Btower Delay I I
(Ignit/r ON)
/
I Timer Started I .[
Gas Valve
NO De-energized YES Post-Purge _'1
, osecond
!
YES
÷
I Ignitor OFF
I stW;ii',i zF°tri°_ %tiei_Y I
i
Set Target Firing Rate
Signals Present
..... Based on Thermostat
I
OR
Call For Heat Satisfied
Error Code Flashes Indoor Blower OFF After
After 5Seconds I I Heat OFF Delay I
J
Switch Opens Error Code
Flashes
Call For 2nd Stage Heat
4_ NO_
YES
Soft Lockout:
Error Code
Flashes
Combustion I_[Soft Lockout: ]
Air Inducer Error Code
OFF Flashes
1
NO
Heat p
-Z_ SOFT LOCKOUT IS RESETAUTOMATICALLYAFTER ONE HOUR WITH ACALL FOR HEAT ACTIVE,_
!
/
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