![background image](http://html.mh-extra.com/html/daikin/altherma-erhq011-014-016ba/altherma-erhq011-014-016ba_installers-reference-manual_501283080.webp)
12 Troubleshooting
Installer reference guide
80
ERHQ+ERLQ011~016 + 16CBV
Daikin Altherma – Low temperature split
4P449970-1 – 2016.06
Possible causes
Corrective action
The water volume in the
installation is too low
Make sure that the water volume
in the installation is above the
minimum required value (see
"6.4.3 To check the water volume
and flow rate" on page 26
).
12.3.2
Symptom: The compressor does NOT
start (space heating or domestic water
heating)
Possible causes
Corrective action
The unit must start up out of its
operation range (the water
temperature is too low)
If the system contains a
backup heater:
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 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 after you
have conducted all of the above
checks, contact your dealer.
If the system does NOT
contain a backup heater
:
The unit is able to perform an
automatic start‑up sequence: if
the space heating circuit is too
cold and defrost operation is
required, the unit will try to
perform defrost operation on the
domestic hot water tank. If this is
NOT possible because the
domestic hot water tank is too
cold, the unit will first preheat the
tank.
If this start‑up sequence does
NOT solve the problem, it may
be required to manually start up
with a small water volume. To do
this, gradually open the heat
emitters. As a result, the water
temperature will gradually rise.
Monitor the inlet water
temperature ([6.1.6] in the menu
structure) and make sure it does
NOT drop below 15°C.
If the problem persists after you
have conducted all of the above
checks, contact your dealer.
The preferential kWh rate power
supply settings and electrical
connections do NOT match
This should match with the
connections as explained in
"6.5 Preparing electrical
wiring" on page 28
and
"7.10.9 To connect the main
power supply" on page 44
.
The preferential kWh rate signal
was sent by the electricity
company
Wait for the power to return (2
hours max.).
12.3.3
Symptom: The pump is making noise
(cavitation)
Possible causes
Corrective action
There is air in the system
Purge air manually (see
"To
perform a manual air purge" on
page 75
) or use the automatic air
purge function (see
"To perform
an automatic air purge" on
page 75
).
The water pressure at the pump
inlet is too low
Check and make sure that:
▪ The water 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
"6.4.4 Changing the pre-
pressure of the expansion
vessel" on page 27
).
12.3.4
Symptom: The pressure relief valve opens
Possible causes
Corrective action
The expansion vessel is broken
Replace the expansion vessel.
The water volume in the
installation is too high
Make sure that the water volume
in the installation is below the
maximum allowed value (see
"6.4.3 To check the water volume
and flow rate" on page 26
and
"6.4.4 Changing the pre-pressure
of the expansion vessel" on
page 27
).
The water circuit head is too high The water circuit head is the
difference in height between the
indoor unit and the highest point
of the water circuit. If the indoor
unit is located at the highest
point of the installation, the
installation height is considered
0 m. The maximum water circuit
head is 10 m.
Check the installation
requirements.
12.3.5
Symptom: The water pressure relief valve
leaks
Possible causes
Corrective action
Dirt is blocking the water
pressure relief valve outlet
Check whether the pressure
relief valve works correctly by
turning the red knob on the valve
counterclockwise:
▪ If you do NOT hear a clacking
sound, contact your dealer.
▪ If the water keeps running out
of the unit, close both the
water inlet and outlet shut-off
valves first and then contact
your dealer.