Table 24: Modulating Gas Heating Faults List - York Sun Premier GZA1M Series Start-Up & Operation

• When flame rectification is established, the con-
troller enters a warm-up cycle to ensure flame sta-
bilization and to reduce condensation forming in
the heat exchanger
• After completing the warm-up cycle, the controller
enters the run cycle
• During the run cycle, the burner firing rate
and draft inducer pressure are determined
based on the heating demand sent via Mo-
dus from the unit controller
• The unit controller determines when more
or less heating capacity is needed and com-
municates this via Modbus to the modulating
gas controller
• The run cycle terminates when
• The heating demand is removed

Table 24: Modulating Gas Heating Faults List

LED Display Diagnostic Code
888 1
OFF 2
Pur
16n
3
HEA
run
rEt 4/5
A01 4
A02 5
A03 6
A04 7
A05 8
A06 9
A07 33
A08 34
A11 24
A15 10
E01 11
E02 12
E03 13
E04 14
E05 15
E08 18
E09 19
E13 23
E18 22
Ed 20
None None
YORK
Type
Lockout Board failure (also during power up)
Status UP mode: burner state = OFF
Status UP mode: burner state = Purge
Status UP mode: burner state = Ignition
Status UP mode: burner state = Warm-up
Status UP mode: burner state = Run
Status UP mode: burner state = Retry
Alert Failed ignition attempt
Alert Lost flame
Alert Insufficient combustion air—auto-derating
Alert Limited low fire (due to lost flame auto adaption)
Alert Weak flame signal, main burner
Alert Reserved
Alert Air modulating failure (inducer isn't modulating down)
Alert Air sensor null pressure check (out of tolerance)
Alert Failed ignition, split manifold burner, retries exhausted
Alert Weak flame signal, one or more split manifold staged burners
Lockout Failed ignition, retries exhausted
Lockout Primary limit failure (or open fuse)
Lockout Modulating valve failure
Air pressure sensor reading low (pressure switch failed to open or
Lockout
insufficient air/blocked vent)
Lockout Air pressure sensor reading high (pressure switch failed to close)
Lockout Unexpected flame, main burner
Lockout No R-W enable signal during CFH
Lockout Open fuse
Lockout Unexpected flame, split manifold burner
Lockout Invalid ID, plug installed
Lockout Board not receiving 24 volts
Start-Up & Operation Guide | 5587001-YSG-A-520
• Any of the gas heat safeties open
• The control reaches its maximum runtime
of 6 hours. When this limit is reached, the
control terminates the run cycle and im-
mediately re-enters heating operation
when a heating demand still exists
• After terminating the run cycle, the 2-stage gas
valve closes and the modulating gas valve returns
to a set position
• The inducer is controlled to the light-off setting for
a 45-second post-purge cycle
• After completing the post-purge cycle, the control-
ler enters the off cycle. In the off cycle, all outputs
are de-energized but all safeties are still monitored
• When more heating capacity is needed, the unit
controller starts staging on other burners (2, 3, or
1B)
Description
55