Error code Malfunction or protection
Low pressure protection in cooling Pe<0.6
HP
occurred 3 times in an hour
Low pressure switch protection
P0
Temperature difference between Tw_out and
Tw_in too high
P5
Pb
Anti-freeze protection
Error due to temperature difference between
TWout and Twin not in line with the operating
mode. The error appears in heating mode
PP
if Twout is less than Twin for more than 15
minutes
126
EN
Failure causeand corrective action
Refer to P0
1. The system refrigerant charge is too low. Search for the leak, repair it and charge with the correct charge. 2.
The water flow is too low in cooling mode. Increase the flow of water. 4. The electrical expansion valve is stuck
or the power connector is loose. Try to unlock the valve by tapping it lightly. Plug / unplug the connector several
times to make sure the valve is working properly.
1. Check that all shut off valves of the water circuit are completely open.
2. Check if the water filter needs cleaning.
3.Make sure there is no air in the system (purge air).
4. Check the water pressure. The water pressure must be >1 bar(water is cold).
5. Check that the pump speed setting is on the highest speed.
6.Make sure that the expansion vessel is not broken.
7. Check that the resistance in the water circuit is not too high for the pump.
Unit will retum to the normal operation autornatically.
1.Check the resistance of the two probe.
2.Check the two probes locations.
3.The water inlet/outlet probe wire connector is loosen. Reconnect it.
4.The water inlet/outlet (lW_in fTW_out) probe is broken, Replace with a new probe.
5.Four-way valve is blocked. Restart the unit again to let the valve the direction.
6.Four-way valve is broken. Replace it with a new valve.
Cod. 3541V941 - Rev. 00 - 09/2021
OMNIA S 3.2