Solving Problems Based On Symptoms; Symptom: The Unit Is Not Heating As Expected; Symptom: The Compressor Does Not Start (Space Heating Or Domestic Water Heating); Symptom: The Pump Is Making Noise (Cavitation) - Daikin EGSQH10S18AA9W Installer's Reference Manual

12 Troubleshooting
WARNING
Prevent hazard due to the inadvertent resetting of the
thermal cut-out: this appliance must NOT be supplied
through an external switching device, such as a timer, or
connected to a circuit that is regularly turned ON and OFF
by the utility.
DANGER: RISK OF BURNING
12.3 Solving problems based on
symptoms
12.3.1 Symptom: The unit is NOT heating as
expected
Possible causes
The temperature setting is NOT
correct
The water or brine flow is too low Check and make sure that:
The water volume in the
installation is too low
Installer reference guide
62
Corrective action
Check the temperature setting on
the remote controller. Refer to
the operation manual.
▪ All shut-off valves of the water
or brine circuit are completely
open.
▪ The water filter is clean. Clean
if necessary.
▪ There is no air in the system.
Purge air if necessary. You
can purge air manually (see
"To perform a manual air
purge" on page 56) or use the
automatic air purge function
(see "To perform an automatic
air purge" on page 56).
▪ The water pressure is >1 bar.
▪ The expansion vessel is NOT
broken.
▪ The resistance in the water
circuit is NOT too high for the
pump.
If the problem persists after you
have conducted all of the above
checks, contact your dealer. In
some cases, it is normal that the
unit decides to use a low water
flow.
Make sure that the water volume
in the installation is above the
minimum required value (see
"6.3.3 To check the water volume
and flow rate of the space
heating circuit and brine
circuit" on page 20).
12.3.2 Symptom: The compressor does NOT
start (space heating or domestic water
heating)
Possible causes
The unit must start up out of its
operation range (the water
temperature is too low)
The preferential kWh rate power
supply settings and electrical
connections do NOT match
The preferential kWh rate signal
was sent by the electricity
company
12.3.3 Symptom: The pump is making noise
(cavitation)
Possible causes
There is air in the system
The pressure at the pump inlet is
too low
12.3.4

Symptom: The pressure relief valve opens

Possible causes
The expansion vessel is broken
The water or brine volume in the
installation is too high
Corrective action
If the water temperature is too
low, the unit uses the backup
heater to reach the minimum
water temperature first (15°C).
Check and make sure that:
▪ The power supply to
backup heater is correctly
wired.
▪ The backup heater thermal
protector is NOT activated.
▪ The backup heater contactors
are NOT broken.
If the problem persists after you
have conducted all of the above
checks, contact your dealer.
This should match with the
connections as explained in
"6.4 Preparing electrical
wiring" on page 22 and "7.6.6 To
connect the main power
supply" on page 30.
Wait for the power to return (2
hours max.).
Corrective action
Purge air manually (see "To
perform a manual air purge" on
page 56) or use the automatic air
purge function (see "To perform
an automatic air purge" on
page 56).
Check and make sure that:
▪ The pressure is >1 bar.
▪ The manometer is not broken.
▪ The expansion vessel is NOT
broken.
▪ The pre-pressure setting of the
expansion vessel is correct
(see "6.3.4 Changing the pre-
pressure of the expansion
vessel" on page 21).
Corrective action
Replace the expansion vessel.
Make sure that the water or brine
volume in the installation is below
the maximum allowed value (see
"6.3.3 To check the water volume
and flow rate of the space
heating circuit and brine
circuit" on page 20 and
"6.3.4 Changing the pre-pressure
of the expansion vessel" on
page 21).
EGSQH10S18AA9W
Daikin Altherma ground source heat pump
4P351748-1D – 2016.02
the