Heatrae Sadia HI-MAX INSTANT ID 5-60 User manual

HI-MAX INSTANT Indirect HIU
Installation, operation and maintenance manual
HImax Instant

2
1. Introduction ............................................................... 3
1.1 General ................................................................. 3
1.2 Symbols used ....................................................... 3
1.3 Abbreviations ....................................................... 3
1.4 Liabilities............................................................... 3
2. Safety.......................................................................... 4
2.1 General safety warnings ...................................... 4
2.2 Recommendations............................................... 4
2.3 Specific safety instructions .................................. 4
3. Technical specifications ............................................ 6
3.1 Technical data ...................................................... 6
3.2 HI-MAX INSTANT ID 5-60 performance data.... 7
3.3 HI-MAX INSTANT ID 5-80 performance data.... 8
3.4 HI-MAX INSTANT ID 5-60 and 5-80
heating performance data ........................................ 9
3.5 Dimensions and connections............................. 10
3.6 1st fix rail and stand-off piping assemblies....... 11
3.7 Electrical diagram(s)............................................ 12
3.8 Pipework and Instrumentation (P & I) diagram.14
3.9 P & I diagram legend.......................................... 17
3.10 District heating schemes - demarcation ......... 18
3.11 District heating schemes - pressure breaks.... 19
4. Description of the product...................................... 20
4.1 General description ............................................ 20
4.2 Operation principle ............................................ 20
4.3 Main components............................................... 22
4.4 Standard delivery................................................ 24
5. Before installation .................................................... 25
5.1 Installation regulations ....................................... 25
5.2 Installation requirements.................................... 25
5.3 Transport and storage ........................................ 25
5.4 Choice of location............................................... 25
5.5 Positioning and access ....................................... 25
6. Installation................................................................. 26
6.1 General ................................................................ 26
6.2 Water connections.............................................. 26
6.3 Wall fixing ............................................................ 27
6.4 Wall fixing procedure.......................................... 27
6.5 HIU fixing procedure .......................................... 27
6.6 Community heating flow and return
connections ............................................................... 28
6.7 Cold water supply connection........................... 28
6.8 Domestic hot water flow connection ................ 28
6.9 Apartment heating flow and return
connections ............................................................... 29
6.10 Apartment heating safety valve
discharge connection ............................................... 29
6.11 Electrical connections....................................... 29
6.12 Filling the installation ....................................... 30
6.13 Completing the installation ............................. 31
7. Commissioning......................................................... 32
7.1 General ................................................................ 32
7.2 Checklist before commissioning ....................... 32
7.3 Commissioning procedure................................. 32
8. Operation ................................................................. 35
8.1 General ................................................................ 35
Contents 9. Maintenance............................................................. 37
9.1 General ................................................................ 37
9.2 Routine inspection & maintenance
operations domestic hot water system................... 37
9.3 Routine inspection & maintenance
operations community heating system................... 38
9.4 Routine inspection & maintenance
operations - apartment heating system.................. 39
10. Troubleshooting ..................................................... 40
10.1 Fault finding ...................................................... 40
10.2 Fault codes ........................................................ 42
11. Decommissioning .................................................. 44
11.1 Decommissioning procedure........................... 44
11.2 Environmental information............................... 44
12. Warranty.................................................................. 44
13. Spare parts.............................................................. 45
14. Commissioning / product installation & service
documentation............................................................. 52

3
1. Introduction
1.1 General
The following instructions are offered as a guide to the
user and installer.
The installation must be carried out by a competent
plumbing and electrical installer in accordance
with Building Regulations, The Building Standards
(Scotland) Regulations 1990, The Building Regulations
(Northern Ireland), UK Water Regulations and IEE
Electrical Regulations.
1.2 Symbols used
In these instructions various risk levels are employed to
draw the user’s attention to particular information. In
doing so we wish to safeguard the user, avoid hazards
and guarantee the correct operation of the appliance.
DANGER
Risk of a dangerous situation causing serious
physical injury.
WARNING
Risk of dangerous situation causing slight
physical injury.
CAUTION
Risk of material damage.
Signals important information.
1.3 Abbreviations
DHW - Domestic hot water
PRV - Pressure reducing valve
Prv - Pressure relief valve
HIU - Hydraulic interface unit
PICV - Pressure independent control valve
Stv - Safety tempering valve
PID - Proportional integral derivative
1.4 Liabilities
Manufacturers liability
Our products are manufactured in compliance with the
requirements of applicable European Directives.
This appliance complies with the requirements of
the CE marking directive and is Kiwa approved to
show compliance with Water Regulations and Nemko
approved for electrical safety.
In the interest of customers we are continuously
endeavouring to make improvements in product
quality. All the specifications stated in this document
are therefore subject to change without notice.
Our liability as the manufacturer may not be invoked in
the following cases:
Failure to abide by the instructions on using the
appliance.
Faulty or insufficient maintenance of the appliance.
Failure to abide by the instructions on installing the
appliance.
Installer's liability
The installer is responsible for the installation and the
commissioning of the appliance. The installer must
respect the following instructions:
Read and follow the instructions given in the
manuals provided with the appliance.
Carry out installation in compliance with the
prevailing legislation and standards.
Perform the initial start up and carry out any checks
necessary.
Complete the commissioning checklist.
Explain the installation to the user.
If maintenance is necessary, warn the user of the
obligation to check the appliance and maintain it
in good working order.
Leave all the instruction manuals to the user.
Users liability
To guarantee optimum operation of the appliance, the
user must respect the following instructions:
Read and follow the instructions given in the
manuals provided with the appliance.
Call on qualified professionals to carry out
installation and initial start up.
Ask the installer to explain the installation.
Have the required checks and services carried out
annually.
Keep the instruction manuals in good condition
and close to the appliance.

4
2. Safety
2.1 General safety warnings
2.2 Recommendations
WARNING
Do not adjust the safety tempering
valve (Stv). This is factory set to prevent
excessive hot water temperatures
reaching the taps in the event of
a system failure (see figure 1). The
purpose of this valve should not be
confused with that of a point of use
mixing valve which is fitted near to the
tap to prevent scalding.
Do not tamper with any of the safety
valves fitted to the system. If a fault
is suspected contact a competent
installer (see figure 1).
WARNING
Only competent persons having
received the appropriate training are
permitted to work on the appliance
and the installation.
Do not tamper with any of the safety
valves or controls supplied with the
unit.
Before any work, isolate the mains
electrical supply to the appliance.
DANGER
This unit becomes pressurised when in
operation. The combination of pressurisation
and hot water could lead to serious physical
injury if the safety instructions in this manual
are not adhered to.
The unit is also designed to work at district
heating hydraulic pressures up to 10 bar g and
temperatures up to 90OC, which, if exposed to
could lead to serious physical injury.
WARNING
When handling the unit, take appropriate
precautions for the weight and stability of the
unit. Weights can be found in section 3, p6.
CAUTION
Annual maintenance must be carried out
by a competent person. Failure to do so will
invalidate the warranty
Figure 1: HIU Safety Valves
Safety Tempering Valve (Stv) Heating Prv
WARNING
Under no circumstances should the
factory fitted safety valves (Stv and Prv)
be removed by anyone other than a
competent person. The unit must not
be run if either of these safety valves
have been removed. Doing so will
invalidate any guarantee or claim.
Although the unit is suitable for cold
water pressures up to 10 bar g it is
strongly recommended that pressures
above 3 bar g are reduced down using
a suitable PRV fitted in the cold feed
pipework.
Where water hammer may be an issue
fit a suitably sized potable water shock
arrester / expansion vessel.
Although the water regulations allow
potable water expansion from this
type of product to be accommodated
in cold water supply pipework, if there
is a back flow prevention device (eg.
check valve) fitted in this pipework, a
potable water expansion vessel should
be fitted to hold the expanded system
water volume (see Figures 17 and 18).
Where expansion vessels have been
fitted, it is good practice to protect the
system in the event of its failure using a
suitable potable water safety valve.
No control or safety valves should be
tampered with or used for any other
purpose.
The Prv discharge pipe should not be
blocked or used for any other purpose.
Where a tundish is fitted, this should not
be located adjacent to any electrical
components.
2.3 Specific safety instructions

5
WARNING
Advice relating to the pump within the
HIU due to strong magnetic field in the
pump motor.
Inside the pump there is always a
strong magnetic field that can cause
injury and damage to property in the
event of incorrect dismantling.
It is only permitted to have the rotor
removed from the motor housing by
qualified personnel.
Take care when pulling the rotor out of
the motor, it may be suddenly pulled
back into its initial position by the
strong magnetic field.
Other electronic devices may be
impaired functionally or damaged by
the strong magnetic field of the motor.
If the rotor is outside the motor,
magnetic objects may be attracted
very suddenly. That can result in injury
and damage to property.
In assembled condition, the rotor's
magnetic field is guided in the motor's
iron core. There is therefore no harmful
magnetic field outside the pump motor.
DANGER
Advice relating to the pump within the
HIU due to strong magnetic field in the
pump motor.
If the unit consisting of impeller, bearing
shield and rotor is pulled out of the
motor, persons with medical aids, such
as cardiac pacemakers, insulin pumps,
hearing aids, implants or similar are at
risk. Death, severe injury and damage
to property may be the result. For
such persons, a professional medical
assessment is always recommended.
Incorrect installation and electrical
connection can result in an electric
shock or even a fatal injury.
Installation and electrical connection
may only be carried out by a qualified
personnel and in accordance with the
applicable regulation!
Any damage to the electrical cables
must be rectified by a qualified
electrician only.
DANGER
The pump will generate electricity if
the impellar is able to turn. As such
it is important that the hydraulic
system and the electrical supply is
isolated before any work is carried
out on the pump.
This appliance can be used by
children aged from 8 years and
above and persons with reduced
physical, sensory or mental
capabilities or lack of experience
and knowledge if they have been
given supervision or instruction
concerning use of the appliance
in a safe way and understand
the hazards involved. Children
shall not play with the appliance.
Cleaning and user maintenance
shall not be made by children
without supervision.
Children must be supervised to
ensure they do not play with the
appliance.
A means for disconnecting
the power supply must be
incorporated in the fixed wiring in
accordance with BS EN 7671:2008
This unit is designed to be
permanently connected to the
hydraulic systems and as such
flexible hose connections should
not be used.
Details of how the unit should be
fixed to its support can be found
on page 27.
For maximum and minimum cold
water inlet pressures see table 1
on page 6.
The unit is fitted with an integral
pressure relief valve. Water may
drip from the discharge pipe of the
pressure-relief valve and this can be
witnessed through a tundish open
to atmosphere. Where discharge
pipework is piped to a drain, a trap
to prevent foul odours should be
installed. The pressure relief valve
should be operated regularly to
remove lime deposits and to verify
it is not blocked. Other advice
relating to the safety valve and its
discharge pipework can be found
on page 29.
The unit is fitted with drain valves
on all three hydraulic circuits as
detailed in figure 22.

6
3. Technical specifications
Table 1: Technical data
Technical Data ID 5-60 ID 5-80
Maximum inlet pressure (DHW) 1.0 MPa (10 bar)
Minimum inlet pressure (DHW) at 25 l/min 0.15 MPa (1.5 bar)
Maximum pressure (District Heating) 1.0 MPa (10 bar)
Maximum pressure (Apartment Heating) 0.30 MPa (3.0 bar)
Apartment heating pressure relief valve setting (Prv) 0.30 MPa (3 bar)
Maximum primary temperature 90OC
Maximum DHW temperature (Safety TMV setting) 60OC
Maximum heating temperature 85OC85
OC
Maximum output in DHW mode (1) 62.8kW 78.75kW
Nominal unit output in heating mode (2) 10.43kW 13.15kW
Maximum chloride content in systems 100 mg/l at 80OC
Maximum primary pressure differential (3) 400 kPa
Minimum primary pressure drop at maximum design flow rate
(hot water mode) (4) 58 kPa 78 kPa
Maximum primary design flow rate below maximum primary pressure
differential (in DHW mode)
990
litres / hour
1330
litres / hour
Maximum primary flow rate (Heating mode) 390 litres / hour 480 litres / hour
Min / Max DHW flow rate at 55OC (45K temperature rise) at 85OC primary
flow temperature (5) 2.7 - 19.8395 litres / min 2.7 - 24.95 litres / min
Heating pump nominal head capacity 60 kPa 60 kPa
Primary flow rate in zero demand pulsed flow mode 100 l/hr 100 l/hr
Electrical supply to HIU 1ph / 50Hz / 230V
Maximum power consumption (6) 53W
Heat loss (kWh in 24h) in zero demand pulsed flow mode
at 85OC district flow (7) 0.364 kWh/day
Product Code Product Name Gross Weight Net Weight
95:050:202 Heatrae Sadia HI-MAX INSTANT ID 5-60 HIU 26.2 kg 24.8 kg
95:050:203 Heatrae Sadia HI-MAX INSTANT ID 5-80 HIU 26.6 kg 25.0 kg
95:970:040 Heatrae Sadia HI-MAX INSTANT ID HIU Casing 10 kg 8.4 kg
95:970:042 Heatrae Sadia HI-MAX INSTANT ID HIU Standard First Fix Rail 5.4 kg 3.9 kg
95:970:602 Heatrae Sadia HI-MAX INSTANT ID HIU Basic Stand-off Kit 8.9 kg 7.1 kg
95:970:046 Heatrae Sadia HI-MAX INSTANT ID HIU Stand-off Kit A 10.2 kg 8.4 kg
95:970:047 Heatrae Sadia HI-MAX INSTANT ID HIU Stand-off Kit B 9.7 kg 7.9 kg
95:970:048 Heatrae Sadia HI-MAX INSTANT ID HIU Stand-off Kit C 9.5 kg 7.7 kg
95:970:049 Heatrae Sadia HI-MAX INSTANT ID HIU Stand-off Kit D 9.5 kg 7.7 kg
(1) Based on a district flow temperature of 85OC.
(2) Output based on a primary flow temperature at 75OC and
heating flow temperature of 60OC at maximum primary flow rate
in heating mode. Higher heating outputs can be achieved by resetting
the maximum primary flow rate.
(3) Maximum Delta P of the PICV.
(4) Excludes pressure drop through the heat meter.
(5) Minimum flow rate is subject to flow sensor tolerances.
(6) At maximum pump speed.
(7) Based on 20OC ambient air temperature.
NB: Primary flow and District flow are the same.
Table 2: Product codes
The HI-MAX INSTANT ID HIU heats the hot water instantaneously as it passes through the DHW plate heat exchanger within the unit.
The performance capabilities of the unit are detailed in Figures 2 and 5 of these instructions.
3.1 HI-MAX INSTANT ID technical data

7
00.10 0.20 0.30 0.40
10
20
30
40
50
60
70
District Flow (l/s)
District flow pressure drop
Delta P (kPa)
3.2 HI-MAX INSTANT ID 5-60 performance data
The DHW output performance of the Heatrae Sadia
HI-MAX INSTANT HIU is related to the district flow
temperature and district flow rate available.
Figure 2 DHW Performance HI-MAX INSTANT ID 5-60
DHW Flow (l/min )
0510 15 20 25
0
0.2
0.4
0.6
0.8
1.0
Delta P (bar)
1.2
1.4
1.6
DHW flow pressure drop
Figure 3 District flow pressure drop Figure 4 DHW flow pressure drop
Note: District flow pressure drop excludes heat meter.
00.511.522.53
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0
5
10
15
20
25
0 0.05 0.1 0.15 0.2 0.25 0.3
P
PICV Settings
DHW Flow Rate (l/sec)
DHW Flow Rate (l/min)
District Flow Rate (l/sec)
85OC
District Flow Temp
DHW output
based on 10OC
cold feed and
55OC DHW flow.
80OC
75OC
70OC
65OC

8
DHW Flow (l/min )
0510 15 20 25
0
0.5
1.0
1.5
2.0
2.5
Delta P (bar)
30
DHW flow pressure drop
3.3 HI-MAX INSTANT ID 5-80 performance data
The DHW output performance of the Heatrae Sadia
HI-MAX INSTANT HIU is related to the district flow
temperature and district flow rate available.
Figure 5 DHW Performance HI-MAX INSTANT ID 5-80
Figure 6 District flow pressure drop Figure 7 DHW flow pressure drop
00.511.522.533.54
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.5
0
5
10
15
20
25
30
0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4
PICV Settings
DWH Flow Rate (l/sec)
DWH Flow Rate (l/min)
District Flow Rate (l/sec)
00.10 0.20 0.30 0.40
10
20
30
40
50
60
70
District Flow (l/s)
District flow pressure drop
Delta P (kPa)
80
Note: District flow pressure drop excludes heat meter.
DHW output
based on 10OC
cold feed and
55OC DHW flow. 85OC
District Flow Temp
80OC
75OC
70OC
65OC

9
3.4 HI-MAX INSTANT ID 5-60 and 5-80 heating performance data
Wilo-Yonos PARA RS 15/6, 25/6, 30/6
ŕp-v (variable)
0 0,5 1,0 1,5 2,0 2,5 3,0
0 0,2 0,4 0,6 0,8
0246810
0
1
2
3
4
5
6
0
10
20
30
40
50
60
0 0,5 1,0 1,5 2,0 2,5 3,0
0
20
40
Wilo-Yonos PARA RS
15/6, 25/6, 30/6
1~230 V - Rp½, Rp 1, Rp 1¼
p
/
kPa
H/m
P
1
/W
Q/m³/h
Q/l/s
Q/Igpm
Q/m³/h
max.
Δp-v
max.
Wilo-Yonos PARA RS 15/6, 25/6, 30/6
Constant speed I, II, III
0 0,5 1,0 1,5 2,0 2,5 3,0
0 0,2 0,4 0,6 0,8
0246810
0
1
2
3
4
5
6
0
10
20
30
40
50
60
0 0,5 1,0 1,5 2,0 2,5 3,0
0
20
40
800
1
/min
2390
1
/min
3400
1
/min
4300
1
/min
Wilo-Yonos PARA RS
15/6, 25/6, 30/6
1~230 V - Rp½, Rp 1, Rp 1¼
p
/
kPa
H/m
P
1
/W
Q/m³/h
Q/l/s
Q/Igpm
Q/m³/h
max.
max.
2.50
00.10 0.20 0.30
Heating Flow (l/s)
5.00
7.50
10.00
12.50
15.00
17.50
20.0
Pressure drop through HIU on heating side
0
Delta P (kPa)
Figure 10 HIU pressure drop on heating side
Figure 8 Pump duty performance curves
(variable pressure setting)
Figure 9 Pump duty performance curves
(constant speed setting)
0.05 0.15 0.25

10
Note: All dimensions are in mm and are reference only
3.5 Dimensions and connections
Table 3: Dimensional data
Figure 11 Dimensions
3.5.1 Dimensional details
Access for services
Sides = 10mm
Front = 1000mm (1)
Top = 100mm
Bottom = 100mm (3)
(1) Access is gained from the front.
(2) Unit with 1st fix rail detailed, allow
an additional 40mm when using the
stand-off kits A, B, C and D.
(3) Access for casing screws.
1 2
3 4 6 57
Connection ID 5-60 & ID 5-80
(1) Community Heating Flow Connection 3/4" BSP Female
(2) Community Heating Return Connection 3/4" BSP Female
(3) Domestic Hot Water Flow Connection 3/4" BSP Female
(4) Apartment Heating Flow Connection 3/4" BSP Female
(5) Apartment Heating Return Connection 3/4" BSP Female
(6) Cold Feed Connection 3/4" BSP Female
(7) Heating Safety Valve Discharge Connection 15mm Pipe
711
776
507
279
39
(2)

11
Figure 12 Different connection options
3.6 1st fix rail and stand-off kits
First Fix rail - 1 - Standard Configuration - 95:970:042
Top Connections: District Flow and District Return
Bottom Connections: DHW Flow, Cold Feed, Heating
Flow and Heating Return
Stand-off kit - B - 95:970:047
Bottom Connections: District Flow, District Return,
DHW Flow , Cold Feed, Heating Flow and Heating
Return
Stand-off kit - D - 95:970:049
Top Connections: District Flow, District Return, Heating
Flow and Heating Return
Bottom Connections: DHW Flow and Cold Feed
Stand-off kit - C - 95:970:048
Top Connections: District Flow, District Return, DHW
Flow and Cold Feed,
Bottom Connections: Heating Flow and Heating Return
Stand-off kit - A - 95:970:046
Top Connections: District Flow, District Return, DHW
Flow and Cold Feed, Heating Flow and Heating Return
Note: Prv discharge connection at bottom on all ID models
Basic Stand-off kit - 95:970:602
Top Connections: District Flow and District Return
Bottom Connections: DHW Flow, Cold Feed, Heating
Flow and Heating Return

12
3.7 Electrical diagrams
A safe means of electrically isolating the HIU must be provided.
Figure 13: Wiring diagram for the heating and hot water controls
230VAC
MAINS
SUPPLY
EARTH
NEUTRAL
LIVE
FUSE
PUMP
MOTOR M
MM
SAFETY THERMAL SWITCH
N.C.
DUAL
MOTOR
DIVERTING
VALVE
L1 NL2
DIVERTING VALVE
NL1
PUMP
N
230VAC IN
L
mA
VDC
COM 24VAC Y
MIX
OPT.OUT
+
- OPT.IN
+
-
AUX
SWITCH
PRESS.
SWITCH
CHRONO
THERM
FLOW METER
C - + T. EXT T. AUX T. HEAT
T.RISC
T. DHW
T.ACS
M
PICV
MODULATING
MOTOR CONTROL
FLOW SWITCH OR
PREPAYMENT CONTACT
LOW PRESSURE
SWITCH
N.O.
N.C.
100R
HALL
EFFECT
SENSOR
COLD WATER
FLOW
METER
NTC10K
PT1000
PT1000
PT1000
DHW FLOW SENSOR
HTG FLOW SENSOR
HTG RETURN SENSOR
OUTDOOR SENSOR
RED
BROWN
BLACK
BROWN
BLACK
BLUE
BLACK
RED
GREY
Safety thermal
switch fitted to
protect low
temperature
heating systems.
(By others).
BLUE
BROWN
630mA
N.O.
N.C.
ROOM STAT
SWITCH
N.O. OR N.C.
DANGER
Ensure the HIU is earthed in accordance with BS EN 7671:2008
For information on outdoor sensors and weather
compensation refer to separate document.

13
3
230VAC MAINS
SUPPLY FUSED AT
3AMP HTG ZONE 1
PROGRAMMABLE
ROOM STAT
2
L
N
E
L
N
EHTG ZONE
VALVE 1
HTG ZONE
VALVE 2
3
HTG ZONE 2
PROGRAMMABLE
ROOM STAT
2
L
N
E
HIU
L
N
E
WIRING CENTRE
FUSE
L
N
E
T1
T2
A safe means of electrically isolating the HIU must be provided.
DANGER
Ensure the HIU is earthed in accordance with BS EN 7671:2008
Figure 15: Wiring diagram for two heating zones
3
230VAC MAINS
SUPPLY FUSED AT
3AMP HTG ZONE 1
PROGRAMMABLE
ROOM STAT
2
L
N
E
L
N
EHTG ZONE
VALVE 1
HIU
L
N
E
WIRING CENTRE
FUSE
L
N
E
T1
T2
Figure 14: Wiring diagram for one heating zone
The wiring schematics within this document are for guidance only and do not constitute system design.
Figure 14 details a single heating zone valve, which may be required on systems where gravitation is a
potential issue.

14
3.8 Pipework and Instrumentation (P & I) Diagram
Figure 16: P & I Diagram
12
5
3
46 7
S1
HM1
HM2
HM
S2 S3
P1
P
HI-MAX INSTANT ID Indirect HIU Legend
1 District Flow
2 District Return
3 Apartment Heating Flow
4 Apartment Heating Safety Valve Discharge
5 DHW Flow
6 DHW Cold Feed
7 Apartment Heating Return
S1 DHW Flow Temperature Sensor
S2 Apartment Heating Flow Temperature Sensor
S3 Apartment Heating Return Temperature Sensor
P1 Apartment Heating Low Pressure Switch
P Pressure Gauge
HM Heat Meter Volumetric Flow Meter
HM1 Heat Meter Flow Temperature Sensor
HM2 Heat Meter Return Temperature Sensor (fitted
within the heat meter volumetric flow meter)
The hydraulic schematics within this document are for guidance only and do not constitute system design.
Some components may not be detailed and connection positions have been moved for clarity purposes.
For clarification of the position of the connections refer to Figure 11 on page 10.

15
S1
HM1
HM2
HM
S2 S3
P1
P
FBP
P
A
Heating Zone 2
Heating Zone 1
Figure 17: HI-MAX INSTANT ID Indirect Units - Hydraulic Schematic -
Radiator System Dynamic balancing valve at the end of each branch to
maintain primary flow pipe temperatures during periods
of no demand. Alternatively enable the pulsed flow
bypass function on the HI-MAX INSTANT.
1
2
3
1 District Return
2 District Flow
3 Cold Water Services
The programmable room thermostat should be
installed in the coldest room in the property where
the only heat source is a radiator without TRV. The
radiator should be fitted with lock shield valves to
avoid it being inadvertently isolated. It will then act
as a system bypass and heat dissipater for the system
when there is a small demand on the system.
The hydraulic schematics within this document are for guidance only and do not constitute system design.
Some components may not be detailed and connection positions have been moved for clarity purposes.
For clarification of the position of the connections refer to Figure 11 on page 10.
When installing the HIU avoid pipe runs that promote gravitation. Where pipes have to be installed
directly up from a heat source consider piping in an anti-gravity loop (ie, a section of pipe that goes down
before it rises up).
Radiator systems should be designed to operate at low system temperatures in order to keep district
return temperatures to a minimum.

16
S1
HM1
HM2
HM
S2 S3
P1
P
FBP
P
Underfloor
Controls
Wiring
Centre
MAV MAV
A
HI-MAX
INSTANT ID
Room
Sensor
A
Towel Rail
Room
Sensor
Room
Sensor
Room
Sensor
Figure 18: HI-MAX INSTANT ID Indirect Units - Hydraulic Schematic -
Underfloor Heating Systems
1
2
3
1 District Return
2 District Flow
3 Cold Water Services
The hydraulic schematics within this document are for guidance only and do not constitute system
design. Some components may not be detailed and connection positions have been moved for clarity purposes.
For clarification of the position of the connections refer to Figure 11 on page 10.
When installing the HIU avoid pipe runs that promote gravitation. Where pipes have to be installed
directly up from a heat source consider piping in an anti-gravity loop (ie, a section of pipe that goes down
before it rises up).
The HI-MAX INSTANT HIU is capable of controlling the temperature to the underfloor heating manifold,
thus removing the need to fit a mixing valve as part of the underfloor heating system. That said, if there are
high temperature circuits in addition to the underfloor heating system, a mixing valve will still be required as
detailed in Figure 18. A high temperature limit thermostat should also be fitted.
Dynamic balancing valve at the end of each branch to
maintain primary flow pipe temperatures during periods
of no demand. Alternatively enable the pulsed flow
bypass function on the HI-MAX INSTANT.
CAUTION
The HI-MAX INSTANT is suitable to run at high or low heating temperatures. To avoid the risk
of inadvertently damaging floors etc, the minimum and maximum temperature range that is
adjustable by the end user MUST be limited by the installer during commissioning.

17
Symbol Description Symbol Description Symbol Description
AAV
P
T
S1
S2 S3 S4
Aqua
Stat
Centrifugal fan
Air intake Pump Compressor Pressure Reducing Valve Isolation Valve Lock Shield Valve Non Return Valve Strainer Double Reg. Valve Orifice Plate Commissioning Station Flow Setter Automatic Bypass Valve Safety Valve T & P Valve 3 Port Motorised Valve 2 Port Motorised Valve
Thermostatic Mixing Valve UFH 4 way valve Drain Cock Angle pattern Drain Cock Expansion Vessel Automatic Air Vent Air Separator Pressure Gauge Assembly Thermometer Tundish Temperature Sensor Temperature Sensor Temperature Sensor Temperature Sensor
Aqua Stat Thermostat
Immersion Heater
Thermostatic Radiator Valve Radiator Lock Shield Valve Filling Loop
Flexible Connection
Symbol Description
S5
S6
Temperature Sensor Temperature Sensor
Flow Switch Flow Meter
H
MHeat Meter
Room Stat
Angle Pattern 2 Port Zone Thermostatic Control Valve
3 Port Bypass Thermostatic Control Valve
2 Port Zone Thermostatic Control Valve
STCV
STCV
STCV
Thermostatic Control Valve Sensor
STCV
Programmable Room Thermostat
Run Back Timer
£Pre Payment Unit
Needle Valve
Air Separator
oCCombined Isolation & Check
Valve with Thermometer
Safety Discharge Vessel
Auto Balancing Valve
Dynamic Balancing Valve
HepvO dry trap
Double Check Valve Pressure independent control & balancing valve
Honeywell SMILE controller
STW10WE Room Stat
Stop Cock
smartfit Smartfit Wiring Centre
Combined Auto balancing & on/off zone valve
Relay
Flushing and Filling Points
Return Temperature Limiter
Table 4: P & I diagram legend
3.9 P & I diagram legend

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Figure 19: District Heating - Demarcation
3.10 District Heating Schemes - Demarcation
• Large community heating or district heating systems can be extensive networks covering large demographic
areas. They can be added to later and also linked to other schemes to form an even larger network. As such it is
important that the Mechanical and Electrical Designer takes this into consideration when planning and designing a
suitable system.
• A key consideration for the designer is that of demarcation. It is important that demarcation lines are as clear as
possible to ensure that the responsibility for the maintenance and the up keep of the complete system is easily
understood by all stakeholders. Demarcation is important for small community heating schemes as well as larger
networks.
• Utilising centralised plantrooms in large buildings and separate substations for smaller buildings are
recommended. The use of plate heat exchangers in these plantrooms and substations not only creates clear
demarcation lines that separate the main network from each individual building or estate, they also act as a
pressure break.
• The use of pressure breaks within the network means that taller buildings do not effect the pressure at which other
parts of the network have to work.
• Where plate heat exchangers are deployed, there will be a need for secondary distribution pumps and
pressurisation equipment to be installed.
EC Energy Centre
CPR Central Plantroom
SS Substation
EC CPR CPR
SS
The hydraulic schematics within this document are for guidance only and do not constitute system design.
Some components may not be detailed for clarity purposes.

19
Figure 20: District Heating - Pressure Break
3.11 District Heating Schemes - Pressure Breaks
• On tall buildings and extensive networks it is recommended to install pressure breaks.
• Pressure breaks can be installed in the central plantroom located in the basement as shown in Figure 20 or if the
building is very tall pressure break(s) may have to be installed on a floor part way up the building.
• If the plantroom is on the rooftop, a pressure break part way down the building may be required to protect the
lower floors from high static pressures.
• A means of isolating the pressure break for service and maintenance purposes is recommended.
The hydraulic schematics within this document are for guidance only and do not constitute system design.
Some components may not be detailed for clarity purposes.

20
4. Description of the product
4.1 General description
The Heatrae Sadia HI-MAX INSTANT hydraulic interface
units (HIUs) are a series of wall mounted units that
interface with a community heating system to produce
domestic hot water instantaneously using plate heat
exchanger technology. The apartment's heating system
is indirectly heated through a plate heat exchanger
within the HIU, this separates the community heating
system from the apartment's heating system.
There are two models in the range:
HI-MAX INSTANT ID 5-60 (DHW outputs from 5kW to
62.8 kW using 85OC primary flow).
HI-MAX INSTANT ID 5-80 (DHW outputs from 5kW to
78.75 kW using 85OC primary flow).
The unit is supplied complete with all the necessary
safety and control devices needed to allow connection
to the cold water mains and district heating system.
All these components are preset and should not be
tampered with.
The unit is pre-wired and pre-plumbed to allow quick
and easy connection to the "in-apartment" services.
The unit is supplied packed and can be ordered in
three parts so that the unit can be installed in three
phases. The three parts are:
• 1st fix rail / stand-off assembly
• HIU
• HIU casing set
Phase 1 - 1st Fix. This involves fixing into position the
first fix rail / stand-off assembly and piping all systems
to it, ie the community heating system, cold water
services, hot water outlets and heating flow and return
pipework. There is also a connection point for the
apartment heating safety valve discharge pipe. This
allows the installer to carry out all of the plumbing work
in one visit.
As the 1st fix rail incorporates a series of isolation
valves, once the systems are plumbed in, the pipework
can be flushed, filled and tested.
The first fix rail also incorporates the electrical cable
entry point to the unit. This allows the electrician to
route cables to the unit, with the final termination of
cables taking place in phase 2.
Phase 2 - 2nd Fix. When the site build programme
permits, the installer can fit the HIU to the 1st fix rail.
This entails fixing the HIU to the first fix rail, connecting
the isolation valves to the unit, filling and deaerating
the unit and then wiring up and commissioning.
Phase 3 - 3rd Fix. Once the unit is commissioned
the casings can be removed from their protective
packaging and fitted.
4.2 Operation principle
The HI-MAX INSTANT range of HIUs all produce
domestic hot water in the same way, ie instantaneously
through a plate heat exchanger.
The hot water and heating temperatures programmed
in the unit are factory set to 55OC and 60OC respectively,
but can be adjusted to suit the installation design.
The domestic hot water is set to an optimum
setting of 55OC in the factory in accordance
with the recommendations of HSE HSG274. It is
recommended that this isn't adjusted because
lower temperatures increase the risk of bacterial
growth within the hot water system and higher
temperatures increase the risks associated with
scalding. Higher temperature also increase the rate
of scale formation within the hot water system.
4.2.1 The heart of the unit
At the heart of the HI-MAX INSTANT HIU is a PID
(Proportional Integral Derivative) controller which
both monitors and regulates the heating and hot
water systems in order to optimise performance. PID
controllers regulate the rate of change of an output,
the time intervals that the changes (outputs) take place
and the results are then constantly monitored and
adjusted accordingly to be as close as possible.
4.2.2 DHW Operation
As hot water is drawn off, the flow of water is sensed
by the flow sensor within the cold feed section of the
return hydroblock. The PID controller then activates
the diverter to send primary water (district heating
flow) through the DHW plate heat exchanger. At the
same time, the DHW temperature is monitored by
the DHW temperature sensor located in the flow
hydroblock on the left hand side of the unit. The
PID controller modulates the pressure independent
control valve (PICV) to achieve and maintain the DHW
set temperature. The more hot water that is drawn off,
the more the PICV will open to allow more district heat
through the HIU.
Figure 21: Indirect HIU plate heat exchangers
DHW Plate Heat
Exchanger
Heating Plate
Heat Exchanger