Setting Up The Domestic Hot Water Tank; System Layout - Standalone Dhw Tank; Selecting The Volume And Desired Temperature For The Dhw Tank - Rotex HPSU Bi-Bloc Ultra Series Installer's Reference Manual

5 Application guidelines
▪ Connect X1 and X2 (changeover to external heat source) on the
digital I/O PCB to the auxiliary boiler thermostat. See
connect the changeover to external heat
▪ To setup the heat emitters, see
system" [ 4 10].
cooling
Configuration
Via the user interface (configuration wizard):
▪ Set the use of a bivalent system as external heat source.
▪ Set the bivalent temperature and hysteresis.
NOTICE
▪ Make sure the bivalent hysteresis has enough
differential to prevent frequent changeover between
indoor unit and auxiliary boiler.
▪ Because the outdoor temperature is measured by the
outdoor unit air thermistor, install the outdoor unit in the
shadow so that it is NOT influenced or turned ON/OFF
by direct sunlight.
▪ Frequent changeover may cause corrosion of the
auxiliary boiler. Contact the manufacturer of the
auxiliary boiler for more information.
Changeover to external heat source decided by an auxiliary
contact
▪ Only possible in external room thermostat control AND one
leaving water temperature zone (see
system" [ 4 10]).
heating/cooling
▪ The auxiliary contact can be:
▪ An outdoor temperature thermostat
▪ An electricity tariff contact
▪ A manually operated contact
▪ ...
▪ Setup: Connect the following field wiring:
L
Com
H
Indoor/Auto/Boiler
A
K1A K2A
N
B Boiler thermostat input
TI
A Auxiliary contact (normally closed)
H Heating demand room thermostat (optional)
K1A Auxiliary relay for activation of indoor unit (field supply)
K2A Auxiliary relay for activation of boiler (field supply)
Indoor Indoor unit
Auto Automatic
Boiler Boiler
NOTICE
▪ Make sure the auxiliary contact has enough differential
or time delay to prevent frequent changeover between
indoor unit and auxiliary boiler.
▪ If the auxiliary contact is an outdoor temperature
thermostat, install the thermostat in the shadow so that
it is NOT influenced or turned ON/OFF by direct
sunlight.
▪ Frequent changeover may cause corrosion of the
auxiliary boiler. Contact the manufacturer of the
auxiliary boiler for more information.
Installer reference guide
16
"7.9.15 To
source" [ 4 46].
"5.2 Setting up the space heating/
"5.2 Setting up the space
Indoor
B TI
X2M
35 30 X Y
K1A K2A
5.4 Setting up the domestic hot water
tank
5.4.1 System layout – Standalone DHW tank
a b c d e f
M
f
a Outdoor unit
b Indoor unit
c Heat exchanger
d Backup heater
e Pump
f Shut-off valve
g Motorised 3‑way valve
h Collector (field supply)
i DHW tank
j Heat exchanger coil
FHL1...3 Under floor heating
5.4.2 Selecting the volume and desired
temperature for the DHW tank
People experience water as hot when its temperature is 40°C.
Therefore, the DHW consumption is always expressed as equivalent
hot water volume at 40°C. However, you can set the DHW tank
temperature at a higher temperature (example: 53°C), which is then
mixed with cold water (example: 15°C).

Selecting the volume and desired temperature for the DHW tank

consists of:
1 Determining the DHW consumption (equivalent hot water
volume at 40°C).
2 Determining the volume and desired temperature for the DHW
tank.
Determining the DHW consumption
Answer the following questions and calculate the DHW consumption
(equivalent hot water volume at 40°C) using typical water volumes:
Question
How many showers are needed
per day?
How many baths are needed per
day?
How much water is needed at the
kitchen sink per day?
Are there any other domestic hot
water needs?
Example: If the DHW consumption of a family (4 persons) per day
is as follows:
▪ 3 showers
▪ 1 bath
▪ 3 sink volumes
g h
FHL1
FHL2
i j
FHL3
Typical water volume
1 shower = 10 min×10 l/min =
100 l
1 bath = 150 l
1 sink = 2 min×5 l/min = 10 l
—
RRGA04~08DAV3 + RHBX04+08DA
ROTEX HPSU Bi-Bloc Ultra
4P495262-1B – 2019.10