
–Set the thermostats to max in as many rooms as pos-
sible. Adjust the room temperature via the "Heating”
home screen, rather than turning down the thermostats.
•S1155/S1255 in incorrect operating mode.
–Contact your installer!
•Too low set value on the automatic heating control.
–Go to the Smartguide for help in increasing heating. You
can also change the heating in the "Heating" home
screen.
•Too low or no operating prioritisation of heat.
–Contact your installer!
•"Holiday" activated in menu 6 - "Scheduling".
–Enter menu 6 and deactivate.
•External switch for changing room temperature activated.
–Check any external switches.
•Air in the climate system.
–Vent the climate system.
•Closed valves to the climate system
–Open the valves (contact your installer for assistance
in finding them).
HIGH ROOM TEMPERATURE
•Too high set value on the automatic heating control.
–Go to the Smartguide for help in lowering the heating.
You can also change the heating from the "Heating"
home screen.
•External switch for changing room temperature activated.
–Check any external switches.
UNEVEN ROOM TEMPERATURE.
•Incorrectly set heating curve.
–Fine-tune the heating curve in menu 1.30.1.
•Too high set value on "dT at DOT"..
–Contact your installer!
•Uneven flow over the radiators.
–Contact your installer!
LOW SYSTEM PRESSURE
•Not enough water in the climate system.
–Fill the climate system with water and check for leaks.
In event of repeated filling, contact the installer.
THE COMPRESSOR DOES NOT START
•There is no heating or hot water demand, nor cooling
demand (accessory is required for cooling).
–S1155/S1255 does not call on heating, hot water or
cooling.
•Compressor blocked due to the temperature conditions.
–Wait until the temperature is within the product’s work-
ing range.
•Minimum time between compressor starts has not been
reached.
–Wait for at least 30 minutes and then check if the com-
pressor has started.
•Alarm tripped.
–Follow the display instructions.
WHINING NOISE IN THE RADIATORS
•Closed thermostats in the rooms and incorrectly set
heating curve.
–Set the thermostats to max in as many rooms as pos-
sible. Fine-tune the heating curve via home screen
heating, rather than choking the thermostats.
•Circulation pump speed set too high.
–Contact your installer!
•Uneven flow over the radiators.
–Contact your installer!
Only additional heat
ADD. HEAT ONLY
If you are unsuccessful in rectifying the fault and are unable
to heat the house, you can continue running the heat pump
in emergency mode, or “Add. heat only” mode, while waiting
for assistance. “Add. heat only” mode means that the heat
pump only uses the immersion heater to heat the house.
Set the heat pump to additional heat mode
1. Go to menu 4.1 - "Operating mode".
2. Select “Add. heat only”.
Emergency mode
You can activate the emergency mode both when
S1155/S1255 is running and when it is switched off.
To switch off, restart or activate emergency mode: press
and hold the on/off button for 2 seconds. This brings up a
menu with various options.
To activate emergency mode when S1155/S1255 is switched
off: press and hold the on/off button for 5 seconds. (Deac-
tivate the emergency mode by pressing once.)
NIBE S1155/S1255Chapter 6 | Disturbances in comfort14