81
110327-07 - 2/23
ALTA
Combi Installation, Operating & Service Instructions
Code
Name
Possible Cause
Corrective Action
H06
E06
Flue High
Limit
Heat exchanger dirty.
Inspect heat exchanger and clean flue side of heat
exchanger.
Boiler over-fired.
Reduce maximum firing rate.
H07
E07
Return Temp
Higher than
Supply
Flow through boiler
reversed.
Verify correct piping and pump orientation.
Supply or return sensor
defective or not installed
properly.
Check supply and return sensors, correct installation or
replace if required.
No boiler water flow.
Verify system is purged of air and that appropriate valves
are open. Also verify pump is running and set to speed 3
(Figure 15-2). Check T5-0 A fuse (Figures 20-1 and 20-2),
replace if necessary. Replace pump if necessary.
H08
Return
Sensor Fault
Shorted or miswired return
temperature sensor.
• Check return sensor wiring, correct wiring if necessary.
• Check return sensor, refer to sensor temperature vs.
resistance (Table 19-7). Replace sensor if necessary.
H09
E09
Supply
Sensor Fault
[
9
.
0
or
9
.
1
] Shorted,
opened or miswired supply
temperature sensor.
• Check supply sensor wiring, correct wiring if necessary.
•
Check supply sensor, refer to sensor temperature vs.
resistance (Table 19-7). Replace sensor if necessary.
[
9
.
2
] Temperature difference
between dual elements too
high.
Measure resistance of each thermistor and compare,
refer to sensor temperature vs. resistance (Table 19-7).
Replace sensor if necessary.
H10
DHW Sensor
Fault
Shorted, opened or
miswired DHW temperature
sensor.
• Check DHW sensor wiring, correct wiring if necessary.
• Check DHW sensor, refer to sensor temperature vs.
resistance (Table 19-7). Replace sensor if necessary.
H11
E11
Flue Sensor
Fault
Shorted, opened or
miswired flue temperature
sensor.
• Check flue sensor wiring, correct wiring if necessary.
• Check flue sensor, refer to sensor temperature vs.
resistance (Table 19-7). Replace sensor if necessary.
H12
Outdoor Air
Sensor Fault
Shorted, opened or
miswired outdoor air
temperature sensor.
• Check outdoor air sensor wiring, correct wiring if
necessary.
• Check outdoor sensor, refer to sensor temperature vs.
resistance (Table 19-7). Replace sensor if necessary.
H13
Header Or
Recirculation
on Sensor
Fault
Shorted, opened or
miswired header or
recirculation temperature
sensor.
• Check header or recirculation sensor wiring, correct
wiring if necessary.
• Check header sensor, refer to sensor temperature vs.
resistance (Table 19-7). Replace sensor if necessary.
Recirculation (Comfort)
Mode selected and
recirculation temperature
sensor not installed.
Disable Recirculation (Comfort) Mode or install a
recirculation temperature sensor.
H14
0-10 Vdc /
4-20 mAdc
Input Fault
[
14
.
0
or
14
.
1
]
Shorted or miswired
0-10 Vdc / 4-20 mAdc
input.
(Feature not available with local user display.)
Check 0-10 Vdc/4-20 mAdc input wiring, correct if
necessary.
[
14
.
2
]
Analog input parameter
setup incorrect.
(Feature not available with local user display.)
Check and correct parameter settings.
H17
E17
Invalid
Safety
Parameters
[
17
.
0
] Control in program
mode.
Cycle power.
[
17
.
4
] Boiler Type and
BCC mismatch.
WARNING
Asphyxiation Hazard.
Boiler type is factory set and must match boiler model. Boiler
type BCC determines minimum and maximum blower speeds.
Incorrect BCC could cause hazardous burner conditions and
improper operation resulting in severe personal injury, death or
substantial property damage.
To verify boiler type BCC is correct, a qualified technician
should do the following:
• Check boiler model and insert correct Boiler Type BCC.
• Check wiring to Model Key located inside control enclosure.
[
17
.
1
,
17
.
2
,
17
.
3
,
17
.
5
,
17
.
6
] Control is defective.
Cycle power to control, Press
!
reset
button after power is re-
established. If problem persists replace control or BCC.
[
17
.
7
] Parameter transfer
from a new BCC is
required or in progress.
Remove and reconnect BCC and cycle power. If problem
persists, replace control or BCC.
[
17
.
6
] Invalid fuel or
altitude selection or power
is cycled too soon after a
fuel selection.
Select desired fuel and altitude. If fuel selection [
A06
] on local
display and power is cycled too fast, select original fuel to clear
alarm before reselecting desired fuel.
[
17
.
8
] BCC is missing,
has incompatible software
revision or is damaged.
Remove and reconnect BCC and cycle power. Press
!
reset
button after power is re-established. If problem persists,
replace control or BCC.
!
19
Troubleshooting
(continued)
Table 19-5: Active Fault Code and Corrective Actions (continued)
Detailed Fault Code found on "
b
" and "
c
" menus in brackets, e.g. [
1
.
0
].
Code
Name
Possible Cause
Corrective Action
E15
APS
Defective
(failed to
open)
Defective air proving
switch, failed to open.
• Remove jumper from air proving switch.
• Check switch, tube connection, and wiring. Check tube is
connected and unobstructed. Replace if necessary.
The blower is running
when it should not.
Blower is running before start sequence. This can be caused
by a loss of communication between blower and control,
resulting in blower going to max speed. Possible cause is a
defective wiring harness, blower or control.
H16
E16
Low
Combustion
Air Flow
Air flow is blocked.
Check vent, air inlet, heat exchanger and burner. Remove
obstruction.
Defective air proving
switch.
Check switch, tube connection and wiring. Check tube is
connected and unobstructed. Replace if necessary.
Blower Fault
Check blower, blower power, control and wiring to blower.
