Symptom: The Pressure Relief Valve Opens; Symptom: The Water Pressure Relief Valve Leaks; Symptom: The Space Is Not Sufficiently Heated At Low Outdoor Temperatures; Symptom: The Pressure At The Tapping Point Is Temporarily Unusually High - Daikin CHYHBH05AA Installer's Reference Manual

Possible causes
The water pressure at the pump
inlet is too low
13.3.5

Symptom: The pressure relief valve opens

Possible causes
The expansion vessel is broken
The water volume in the
installation is too high
The water circuit head is too high The water circuit head is the
13.3.6 Symptom: The water pressure relief valve
leaks
Possible causes
Dirt is blocking the water
pressure relief valve outlet
CHYHBH05+08AA + EHYKOMB33A
Daikin hybrid for multi heat pump – heat pump module
4P471761-1A – 2017.10
Corrective action
Check and make sure that:
▪ The water pressure is >1 bar.
▪ The pressure sensor of the
gas boiler 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 20).
Corrective action
Replace the expansion vessel.
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 19 and
"6.4.4 Changing the pre-pressure
of the expansion vessel" on
page 20).
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 7 m.
Check the installation
requirements.
Corrective action
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.
13.3.7 Symptom: The space is NOT sufficiently
heated at low outdoor temperatures
Possible causes
Gas boiler operation is not
activated
The gas boiler equilibrium
temperature has not been
configured correctly
There is air in the system.
Too much heat pump capacity is
used for heating domestic hot
water (applies only to
installations with a domestic hot
water tank)
13.3.8 Symptom: The pressure at the tapping
point is temporarily unusually high
Possible causes
Failing or blocked pressure relief
valve.
13.3.9 Symptom: Tank disinfection function is
NOT completed correctly (AH-error)
Possible causes
The disinfection function was
interrupted by domestic hot water
tapping
13 Troubleshooting
Corrective action
Check and make sure that:
▪ The gas boiler is switched On
and is NOT in standby mode.
▪ The communication cable
between the gas boiler and the
indoor unit is properly
mounted.
▪ There is no error code on the
gas boiler display.
Increase the "equilibrium
temperature" to activate gas
boiler operation at a higher
outdoor temperature. Go to:
▪ [A.5.2.2] > Installer settings >
Heat sources > Boiler
Equilibrium temp. OR
▪ [A.8] > Installer settings >
Overview settings [5‑01]
Purge air manually or
automatically. See the air purge
function in the "Commissioning"
chapter.
Check and make sure that the
"space heating priority" settings
have been configured
appropriately:
▪ Make sure that the "space
heating priority status" has
been enabled. Go to [A.8] >
Installer settings > Overview
settings [5‑02]
▪ Increase the "space heating
priority temperature" to
activate backup heater
operation at a higher outdoor
temperature. Go to [A.8] >
Installer settings > Overview
settings [5‑03]
Corrective action
▪ Flush and clean the complete
tank including the piping
between pressure relief valve
and the cold water inlet.
▪ Replace the pressure relief
valve.
Corrective action
Program the start-up of the
disinfection function when the
coming 4 hours NO domestic hot
water tapping is expected.
Installer reference guide
79
>