Technical data
Installation, user and maintenance manual – GAHP-GS/WS
83
CODES DESCRIPTION TRIP CONDITIONS RESET METHOD
u 236 BLOWER FAULT Blower fault
Reset occurs automatically 20 minutes after the operating code is 
generated.
E 236 BLOWER FAULT
u_36 code generated three times in 1 hour of 
operation.
Reset may be performed from the CCI/DDC (or from the S61 board 
via menu 2, parameter 1). If the code persists, contact authorised 
TAC.
u 246
HOT INLET WATER TEMPERATURE 
TOO HIGH
Hot inlet water temperature higher than upper 
operating limit of the appliance (if the appliance 
is in operation).
Resets automatically if, with the circulator on, the cause resolves or 
(with circulator off) 20 minutes after generation of code.
u 247 LOW HOT WATER TEMPERATURE
Hot water temperature lower than lower 
operating limit of the appliance (if the appliance 
is in operation).
Reset occurs automatically when cause resolves or 430 seconds 
after the code is generated.
E 247 LOW HOT WATER TEMPERATURE
u_47 code generated 3 times in 1 hour of 
operation of the circulator.
Reset occurs automatically when the condition that generated 
the code ceases. If the code persists, contact authorised Technical 
Assistance.
u 248
HOT WATER DIFFERENTIAL 
TEMPERATURE TOO HIGH
High hot water differential temperature.
Reset occurs automatically 20 minutes after the operating code is 
generated.
E 248
HOT WATER DIFFERENTIAL 
TEMPERATURE TOO HIGH
u_48 code generated twice in 2 hours of 
operation.
Reset may be performed from the CCI/DDC (or from the S61 board 
via menu 2, parameter 1).
E 249 SATELLITE BOARD NOT PRESENT Satellite board not present.
Reset occurs automatically when the condition that generated the 
code ceases.
u 251
ANTIFREEZE FUNCTION ACTIVATED 
- COLD SIDE
Activation takes place only if the 
plant water circulator is off and the 
antifreeze function is enabled (see 
menu 1, parameter 77).
Inlet or outlet water temperature of the cold 
module falls below 4°C (the code generated 
signals that the antifreeze function has been 
activated). In this case the antifreeze function 
activates the plant water circulator.
Reset (deactivation of antifreeze function) occurs automatically 
when, with only the circulator on, the inlet and outlet water 
temperatures return to over 5°C (in this case the circulator switches 
off), or if the function itself is disabled.
u 275
INSUFFICIENT HOT SIDE WATER 
FLOW
On the hot side, the circulator is on and the 
flowmeter is open for 5 seconds (insufficient 
water flow).
The warning automatically resets when the circulator switches off 
or the flow meter closes for 5 seconds.
E 275
INSUFFICIENT HOT SIDE WATER 
FLOW
At the fifth u_75 from machine power supply, 
or after two hours of u_75 presence, the error is 
generated.
Reset may be performed from the CCI/DDC (or from the S61 board 
via menu 2, parameter 1).
E 276
HOT WATER DELIVERY 
TEMPERATURE PROBE FAULT.
Fault (interruption or short circuit) on outlet hot 
water temperature sensor.
Reset may be performed from the CCI/DDC (or from the S61 board 
via menu 2, parameter 1).
E 277
HOT WATER RETURN TEMPERATURE 
PROBE FAULT.
Fault (interruption or short circuit) on inlet water 
temperature sensor.
Reset may be performed from the CCI/DDC (or from the S61 board 
via menu 2, parameter 1).
u 278
OUTLET HOT WATER TEMPERATURE 
TOO HIGH
Outlet hot water temperature too high
Reset is automatic and occurs when the condition that generated 
it ceases to apply.
u 279
DEFROST FUNCTION ACTIVATED - 
HOT SIDE
Activation takes place only if the 
hot module is off and the antifreeze 
function is enabled (see menu 1, 
parameter 163).
Antifreeze function activated (with function 
enabled: see menu 1, item163; and only with 
machine off). In this case the antifreeze function 
activates the plant water circulator. If this 
temperature falls further to below 3 °C, the 
function also activates the flame controller.
Resets automatically (defrost function disabled) if, with only the 
circulator operating, the hot water inlet/outlet temperature rises 
above 5°C (at which point the circulator switches off); or, if also the 
flame controller is on, when the temperature reaches 18 °C (in this 
case the flame controller and then the circulator switch off).
u 280 INCOMPLETE PARAMETERS Incomplete parameters.
The code remains until operating parameters are entered and 
completed. Contact authorised Technical Assistance. If the board 
is replaced, Code E 80 may appear; this means that the unit’s 
characterisation parameters have not been set.
E 80/280 INVALID PARAMETERS
Invalid parameters or damage to parameter 
memory.
Reset occurs automatically when correct parameters are entered. 
If the code persists, contact authorised Technical Assistance: if the 
parameters are incorrect, it is necessary to enter and complete the 
unit operating and characterisation parameters; if the memory is 
damaged, the controller must be replaced.
u 281 INVALID BANK 1 PARAMETERS Invalid Bank 1 data - Bank 2 data OK. Reset occurs automatically 5 seconds after the code is generated.
E 281 INVALID BANK 1 PARAMETERS
The program attempts to resolve the problem by 
writing the second page over the first; if after 5 
attempts this fails, the error is generated.
Reset may be performed from the CCI/DDC (or from the S61 board 
via menu 2, parameter 1). If the code persists, contact authorised 
TAC.
u 282 PARAMETRI BANCO 2NON VALIDI Invalid Bank 2 data - Bank 1 data OK. Reset occurs automatically 5 seconds after the code is generated.
E 282 INVALID BANK 2 PARAMETERS
The program attempts to resolve the problem by 
writing the first page over the second; if after 5 
attempts this fails, the error is generated.
Reset may be performed from the CCI/DDC (or from the S61 board 
via menu 2, parameter 1). If the code persists, contact authorised 
TAC.
E 284
FAULTY TRANSFORMER 
CONNECTION OR 24 V AC FUSES
Damage to one of the 2 24-0-24 V AC transformer 
fuses, or one of 24-0-24 V AC wires to the board 
not supplying current.
Check fuses and 24-0-24 V AC electrical power connections on the 
controller. Reset may be performed from the CCI/DDC (or from the 
S61 board via menu 2, parameter 1). If the code persists or occurs 
again, contact authorised TAC.
E 285
INCORRECT MODULE TYPES (from 
menu 6)
The set module type (from menu 6) does not 
correspond to the one managed by the controller.
Reset occurs automatically when correct parameters are entered. If 
the code persists, contact authorised Technical Assistance.
E 286 MEMORY TEST UNSUCCESSFUL Processor error. Contact authorised Technical Assistance.
E 287 MEMORY TEST UNSUCCESSFUL Processor error. Contact authorised Technical Assistance.
E 288 MEMORY TEST UNSUCCESSFUL Processor error. Contact authorised Technical Assistance.
E 289 MEMORY TEST UNSUCCESSFUL Processor error. Contact authorised Technical Assistance.
E 290
AMBIENT TEMPERATURE SENSOR 
DEFECTIVE
Interruption or short circuit of ambient 
temperature sensor.
Reset may be performed from the CCI/DDC (or from the S61 board 
via menu 2, parameter 1). If the code persists, contact authorised 
TAC.
E 291 CONTROLLER DEFECTIVE
One of the following is absent: serial number of 
board, hardware version code or encryption key 
written during board test.
Contact authorised Technical Assistance.
TABLE OF OPERATING CODES generated by the S61 electronic board (firmware version 3.024)










