88
PHTM II
Combi Installation, Operating & Service Instructions
110331-07 - 8/23
19
Troubleshooting
(continued)
Code Detailed
Code
Type
Condition
H23
E23
E23
.
0
Lockout
Flame detected before burner start.
E23
.
1
Lockout
Flame detected for 15s after gas valve closed.
H23
.
2
Hold
Defective Control: flame amplifier.
E23
.
3
Lockout
Defective Control: flame amplifier. Happens after second
H24
.
2
H24
E24
H24
.
0
Warning
Flame signal loss in operation. Minimum firing rate raised for 1 hour.
H24
.
1
Hold
Flame signal loss in stabilization phase.
H24
.
2
Hold
Flame signal loss in safety time.
E24
.
3
Lockout
Flame signal loss in safety time.
H25
E25
H25
.
0
Hold
Defective control: internal safety core error.
E25
.
2
Lockout
Defective control: internal application core error.
E25
.
3
Lockout
Defective control: internal safety core error.
E25
.
4
Lockout
Defective control: internal safety core error.
E25
.
5
Lockout
Defective control: internal safety core error.
E25
.
6
Lockout
Defective control: unknown internal safety core error.
H26
E26
H26
.
0
Hold
Calibration fault: stable conditions to perform gas valve offset adaptation not
reached.
H26
.
1
Hold
Calibration fault: stable conditions to perform calibration not reached.
E26
.
2
Lockout
Calibration fault: missing calibration. Calibration counter reached zero.
H26
.
3
Warning
Calibration fault: emergency stop during calibration due to high outlet/DHW temp or
blocking/lockout error.
H27
H27
.
0
Hold
120 VAC supply voltage less than 73 VAC.
H28
H28
.
0
Hold
Control 24 VAC wrong frequency or high electrical noise.
E29
E29
.
0
Lockout
Excessive
!
reset
button selection.
H30
H30
.
0
Hold
Duplicate slave boiler addresses.
H30
.
1
Warning
Sequencer slave has lost communication with sequencer master, or master header
sensor failure.
H30
.
2
Hold
Multiple sequencer masters detected.
H30
.
3
Warning
Communication fault: no valid Modbus setpoint signal.
H30
.
4
Warning
Communication fault: no valid Modbus setpoint signal.
H31
H31
.
0
Hold
Variable Speed Pump Fault and pump feedback is used to prove boiler water flow.
H31
.
1
Warning
Variable Speed Pump Fault and flow switch is used to prove boiler water flow.
Table 19-6: Detailed Fault Code (found on"
cc
" and "
bb
" menus, continued)