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.
COMPRESSOR DOES NOT START
• There is no heating or cooling demand (accessory is required for cool-
ing).
– F1255 does not call on heating, cooling or hot water.
• Compressor blocked due to the temperature conditions.
– Wait until the temperature is within the product’s working range.
• Minimum time between compressor starts has not been reached.
– Wait for at least 30 minutes and then check if the compressor has
started.
• Alarm tripped.
– Follow the display instructions.
• "Additional heat only" is selected.
– Switch to "Auto" or "Manual" in menu 4.1 "Operating mode".
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 possible. Adjust
the heating curve via menu 1.1, instead of choking the thermostats.
• Circulation pump speed set too high.
– Contact your installer!
• Uneven flow over the radiators.
– Contact your installer!
GURGLING SOUND
This part of the troubleshooting chapter only applies if the NIBE FLM
accessory is installed.
• Not enough water in the water seal.
– Refill the water seal with water.
NIBE F1255
Chapter 4 | Disturbances in comfort
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