H E A T I N T E R F A C E U N I T
C O M M I S S I O N I N G
Page 24
H E A T I N T E R F A C E U N I T
C O M M I S S I O N I N G
Page 25
Fig. 21
The pre-setting scale indicates values from 100% flow to 0%, the required volume for the DHW control
valve can be found on the HIU label.
The keep warm setting is dependent upon the primary flow temperature, DHW and keep warm valves
model and setting.
VALVE SETTING / FLOW RATE (LITRES PER SECOND)
VALVE
20%
30%
40%
50%
60%
DN10 LF
0.008 l/s
0.013 l/s
0.017 l/s
0.021 l/s
0.025 l/s
DN15 LF
0.015 l/s
0.023 l/s
0.031 l/s
0.038 l/s
0.046 l/s
DN15 NF
0.025 l/s
0.038 l/s
0.050 l/s
0.063 l/s
0.075 l/s
DN15 HF
0.063 l/s
0.095 l/s
0.126 l/s
0.158 l/s
0.189 l/s
DN20 NF
0.050 l/s
0.075 l/s
0.100 l/s
0.125 l/s
0.150 l/s
DN25 NF
0.094 l/s
0.142 l/s
0.189 l/s
0.236 l/s
0.283 l/s
VALVE
70%
80%
90%
100%
DN10 LF
0.029 l/s
0.033 l/s
0.038 l/s
0.042 l/s
DN15 LF
0.053 l/s
0.061 l/s
0.069 l/s
0.076 l/s
DN15 NF
0.088 l/s
0.100 l/s
0.113 l/s
0.125 l/s
DN15 HF
0.221 l/s
0.252 l/s
0.284 l/s
0.315 l/s
DN20 NF
0.175 l/s
0.200 l/s
0.225 l/s
0.250 l/s
DN25 NF
0.331 l/s
0.378 l/s
0.425 l/s
0.472 l/s
Press grey pointer back into lock position when
flow rate set. After click, pre-setting is locked.
Replace actuator.
8.4.2 Heating Control Valve Adjustment
Heating control is provided by a Danfoss Frese
Compact PICV. During the commissioning process
the flow rate will need to be checked and adjusted.
See Fig 21 below which identifies the location of
the heating PICV.
Before undertaking any of the steps below, close
primary system isolation valves at the top of the
HIU and confirm electrical connection is isolated.
CAUTION
The actuators on the valves must not be
dismantled during operation. This could result in
them being destroyed. Dismantling should only
be carried out when the HIU is isolated from all
systems (mechanical and electrical) and when
the system has cooled down.
Table 6.
Fig. 23
Remove thermostatic actuator by loosening the
collar (Fig 22).
Fig. 22
Loosen the brass locking nut on the DHW PICV
(See Fig 23)
and turn the dial so the pointer aligns
with the correct flow setting. Ensure the locking
nut is re-tightened following adjustment.
The required flow setting for the Frese Low 2.5
valve can be found below in Table 4, if any other
valve is installed refer to the manufacturer's data
sheet. The required volume for the HTG control
valve can be found on the HIU label, i.e. if the
required flow rate is 0.029 l/s set the valve to
setting 2, always align the pointer with the next
number above the required flow rate.
Ensure brass locking nut has been re-tightened.
Refit the DHW control valve actuator and open
primary valves at the top of HIU.
Table 8.
FRESE COMPACT DN10 / DN15 - 2.5 LOW
SETTING
0.5
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
2.2
FLOW (l/s)
0.008
0.010
0.012
0.015
0.018
0.020
0.023
0.026
0.029
0.031
SETTING
2.4
2.6
2.8
3.0
3.2
3.4
3.6
3.8
4.0
FLOW (l/s)
0.034
0.037
0.039
0.042
0.045
0.047
0.050
0.053
0.056
KEEP WARM BYPASS SETUP
PRIMARY
FLOW
(°C)
DHW
FLOW
(°C)
PICV
SETTING %
ACTUATOR
SETTING NO.
70
55
100
2.5
60
55
100
1
Table 7.
