Symptom: The Compressor Does Not Start (Space Heating Or Domestic Water Heating); Symptom: The Pump Is Making Noise (Cavitation); Symptom: The Pressure Relief Valve Opens - Daikin Altherma 3 WS EWSAH06UD 9W Series Installer's Reference Manual

15 | Troubleshooting

15.3.2 Symptom: The compressor does NOT start (space heating or domestic water heating)

15.3.3 Symptom: The pump is making noise (cavitation)

15.3.4 Symptom: The pressure relief valve opens

Installer reference guide
234
Possible causes
The compressor cannot start if the
water temperature is too low. The unit
will use the backup heater to reach the
minimum water temperature (5°C),
after which the compressor can start.
The preferential kWh rate power supply
settings and electrical connections do
NOT match
The preferential kWh rate signal was
sent by the electricity company
Domestic hot water (including
disinfection) and space heating
operation are scheduled to start at the
same time.
Possible causes
There is air in the system
The pressure at the pump inlet is too
low
Possible causes
The expansion vessel is broken
Corrective action
If the backup heater doesn't start
either, check and make sure that:
▪ The power supply to the backup
heater is correctly wired.
▪ The backup heater thermal protector
is NOT activated.
▪ The backup heater contactors are
NOT broken.
If the problem persists, contact your
dealer.
This should match with the connections
as explained in "9.2.1 To connect the
4
main power supply" [ 91].
In the user interface of the unit, go to
[8.5.B] Information > Actuators >
Forced off contact.
If Forced off contact is On, the
unit is operating under the preferential
kWh rate. Wait for the power to return
(maximum 2 hours).
Change the schedule to not start both
operation modes at the same moment.
Corrective action
Purge air (see "12.4.1 Air purge function
4
on the water circuit" [
"12.4.2 Air purge on the central water
4
loop circuit" [ 217]).
Check and make sure that:
▪ The pressure is >1 bar.
▪ The expansion vessel is NOT broken.
▪ The pre-pressure setting of the
expansion vessel is correct (see
"8.1.4 Changing the pre-pressure of
the expansion vessel" [
Corrective action
Replace the expansion vessel.
215] or
4
77]).
EWSAH/X06UD
Daikin Altherma 3 WS
4P675765-1 – 2022.04