Zip AquaFlo II AF3090 Mounting instructions

AquaFlo II
Unvented Water Heaters
Issued October 2012
Installation, Maintenance and User Instructions
Please read these instructions carefully before commencing installation.
Please leave these instructions with the end user after installation.
Zip Heaters (UK) Ltd.
14 Bertie Ward Way
Dereham
Norfolk
NR19 1TE
Telephone: [phone]
Fax: [phone]
Web: www.zipindustries.co.uk
The terms ‘Zip’ and ‘InLine’
are registered trademarks
Front cover A5_BookletBack cover

Inside Back cover Inside Front cover

AquaFlo Installation, Maintenance and User Instructions Page 1 of 24 V 2.01 - October / 2012
Contents 1
Description 2
Approvals 2
Safety Information 3
Technical data 4 / 12
Parts List 13
Installation 14
Requirements 14
Installation Site 15
Installing the appliance 15
Electrical connection / circuit diagram 20 / 21
Commissioning 22
Annual servicing 23
Warranty 24
Please read these instructions carefully before commencing installation of the AquaFlo
unvented Water Heater.
Please leave these instructions with the end user after installation.
To ensure you have the latest revision of this instruction manual, please visit
www.zipindustries.co.uk to download the latest copy.
In order to preserve our environment we ask that you dispose of this product correctly.
Please contact Zip Customer Service for advice on 0845 602 4533.

AquaFlo Installation, Maintenance and User Instructions Page 2 of 24 V 2.01 - October / 2012
Equipment Supplied with Cylinder Direct Indirect Solar Twin
Coil
Solar
Direct
Dual Control Thermostat (Indirect Models Only) û  û
Thermostat (High Limit) û û  
Two Port Zone Valve (Indirect Models Only) û  û
Cold Water Inlet Set    
15 x 22 mm Tundish    
Temperature & Pressure Relief Valve    
Expansion Vessel    
Expansion Vessel Bracket    
¾” BSP Female X 22 mm Connection for Expansion Tank    
Immersion Heater(s) - Dependant on size and conguration    
Grommet for Solar Sensor û û  
Instruction Manual    
DESCRIPTION
The corrosion resistant Zip AquaFlo Unvented cylinder is made from Duplex Stainless Steel. It is
highly insulated with environmentally friendly foam enclosed in a rust resistant white steel case.
It is available in Direct and Indirect versions in a family of 7 sizes from 90 – 300 litres. Triple
element options are available on Direct 210 – 300 litre units. Twin Coil and Solar Direct units are
available in 5 sizes from 150 - 300 litres.
To help ensure compliance with the relevant Water and Building Regulations all AquaFlo units
are supplied complete with the necessary safety and control devices needed to connect to the
cold water mains. In order to ensure high ow-rate performance with minimum pressure drop even
in lower pressure areas, pre-adjusted, high quality controls have been selected.
APPROVALS
KIWA approved to UK Water Regulations and UK Building Regulations Part G3 and Part L.
Immersion element / thermostat BEAB / NEMKO approved and CE endorsed.
Storage prior to installation
Zip AquaFlo should be stored upright in a dry area and kept in its original packaging until
immediately prior to installation.
Cold Inlet Set - Connections
Cold Mains In
Balanced Cold Take Off
Cold Supply To Cylinder
Internal Check Valve
Expansion Vessel Take Off
Discharge To Tundish
Expansion Relief Valve
Pressure Reducing Valve (inc.
Line Strainer)
Additional items required (not supplied): Drain for the cold inlet. Isolating valve for the cold feed
supply.

AquaFlo Installation, Maintenance and User Instructions Page 3 of 24 V 2.01 - October / 2012
SAFETY INFORMATION
WARNING
• Installation, commissioning and maintenance of this appliance must only be carried
outbyacompetentinstallerholdingtheirG3unventedqualication, who will then be
responsible for adhering to all relevant standards and regulations.
• The appliance must be wired to a suitably rated double pole fused spur.
• Electrical installation must comply with IEE regulations.
• Isolate appliance at the main electric supply before opening the heating element cover.
• The connection cable must be 2.5mm2 heat resistant (85°C HOFR) sheathed ex complying
to BS 6141:1981.
• This appliance must be earthed at all times.
• The connecting cable must be adequately secured.
• Check that the power supply is switched off prior to electrical connection.
• The appliance, its wiring and piping must not be modied in any way.
• The appliance must only be used when correctly installed and in perfect working order.
• Maximum water supply pressure 1.0 MPa (10 bar) .
• Explosion hazard. Safety ttings such as the temperature & pressure relief valve must not
be modied.
• The appliance must not be used for any purpose other than that for which it was designed.
• When the appliance has been in use for some time, the ttings may be very hot.
• This appliance must not be used by any person (including children) with limited physical,
sensorial or mental abilities or failing experience and/or knowledge unless they are
supervised by a person responsible for their safety or received instructions about how to
use the appliance. Children should be supervised in order to make sure that they do not play
with the appliance.
• Take care when lifting the Zip AquaFlo. Some units may exceed safe lifting limits. Do not
lift without assistance. The weights of the units are given in the specifications table (see
specications on page 10 to 12)
WARNING:
Indicates a potentially hazardous situation, which, if
not avoided, could result in death and/or serious injury
and/or property damage.
CAUTION: Indicates a potentially hazardous situation, which, if not avoided,
may result in property damage.
IMPORTANT:
PLEASE READ THESE INSTRUCTIONS CAREFULLY.
NOTE THE SAFE OPERATIONAL REQUIREMENTS, WARNINGS AND CAUTIONS. USE THIS PRODUCT CORRECTLY
AND WITH CARE FOR THE PURPOSE FOR WHICH IT IS INTENDED. FAILURE TO DO SO MAY CAUSE DAMAGE
AND/OR PERSONAL INJURY, AND WILL INVALIDATE THE WARRANTY. RETAIN THESE INSTRUCTIONS FOR FUTURE
USE.

AquaFlo Installation, Maintenance and User Instructions Page 4 of 24 V 2.01 - October / 2012
CAUTION!
• In case of malfunction isolate the power supply immediately. In case of leaks also isolate the
water supply. Repairs must only be carried out by Zip Heaters (UK) Ltd or an authorised Zip
service engineer.
• If siting outside the heating envelope of the dwelling such as a garage or outbuilding then
frost protection should be provided and exposed pipework should be insulated.
• The appliance must be completely lled with water before being switched on.
• The appliance must only be used for heating wholesome water.
• Minimum water supply 0.15 MPa (1.5 bar), 20 l/min.
• The Zip AquaFlo is intended for connection to mains supply only. In any other case please
contact Zip on 0845 602 4533 for advice.
Zip Heaters (UK) Ltd. cannot be held liable for any damages caused by failure to observe
these instructions.
TECHNICAL DATA / SPECIFICATION
Maximum water supply pressure to pressure reducing valve ...................1.0 MPa (10 bar)
Note! If supply is above 1.0 MPa (10 bar) a pressure control valve must be used to bring
the pressure under 1.0 MPa (10 bar) before connection to the pressure reducing valve.
Operating pressure ....................................................................................0.3 MPa (3 bar)
Maximum primary pressure (indirects only) ...............................................0.3 MPa (3 bar)
Immersion Elements: Incology construction 1¾” thread, 14” long, loading 3kW @ 240V.
Note! Titanium elements are also available for areas where aggressive water, constant cycling
and high usage are factors. (See parts on page 13).
Heat Exchanger: 22mm low prole, high efciency stainless steel coil-in-coil.
Controls:
• Thermostat adjustable up to 65°C.
• Over temperature safety cut-out. Manually re-settable. Operates at 85°C.
• Expansion relief valve -
0.6 MPa (6 bar) .
• Temperature and pressure relief valve - 90°C and 0.7 MPa (7 bar).
• Pressure reducing valve - 0.3 MPa (3 bar).
• Expansion vessel - pre-charged
0.3 MPa (3 bar) .
• 90 - 150 Ltr units: 12 Ltr vessel.
• 180 - 250 Ltr units: 18 Ltr vessel.
• 300 Ltr units: 24 Ltr vessel.

AquaFlo Installation, Maintenance and User Instructions Page 5 of 24 V 2.01 - October / 2012
Connection Points
AquaFlo Indirect and Solar Compatible
Immersion
Cold Inlet
Primary Coil
T&P Valve
Stat Pocket
Sec Return
Primary Coil
38°
35°
25°
40°
66°
15°
Immersion T&P Valve
Cold Inlet
AquaFlo Direct
45°
15°

AquaFlo Installation, Maintenance and User Instructions Page 6 of 24 V 2.01 - October / 2012
AQUAFLO DIRECT DIMENSIONS
Model AF3090 AF3120 AF3150 AF3180 AF3210 AF3250 AF3300
Nominal Capacity (Litres) 90 120 150 180 210 250 300
Diameter (mm) 545 545 545 545 545 545 545
Height (mm) A727 915 1102 1290 1478 1728 2041
T & P Valve (mm) B515 703 890 1078 1266 1516 1829
Sec. Return (mm) C- - - - 1009 1259 1509
Immersion 2 (mm) D- 519 619 719 819 959 1109
Immersion 1(mm) E242 242 242 242 242 242 242
Cold Inlet (mm) F192 192 192 192 192 192 192
A
B
C
D
E
F

AquaFlo Installation, Maintenance and User Instructions Page 7 of 24 V 2.01 - October / 2012
AQUAFLO INDIRECT DIMENSIONS
Model AF4090 AF4120 AF4150 AF4180 AF4210 AF4250 AF4300
Nominal Capacity (Litres) 90 120 150 180 210 250 300
Diameter (mm) 545 545 545 545 545 545 545
Height (mm) A727 915 1102 1290 1478 1728 2041
T & P Valve (mm) B515 703 890 1078 1266 1516 1829
Sec. Return (mm) C- - - - 1159 1409 1609
Immersion 2 (mm) D- - - - - 959 1109
Stat Pocket (mm) E354 354 394 394 474 569 669
Immersion 1 (mm) F339 339 379 379 414 414 414
Bottom Coil (mm) G299 299 339 374 374 374 374
Cold Inlet (mm) H192 192 192 192 192 192 192

AquaFlo Installation, Maintenance and User Instructions Page 8 of 24 V 2.01 - October / 2012
AQUAFLO SOLAR TWIN COIL DIMENSIONS
Model AF5150 AF5180 AF5210 AF5250 AF5300
Nominal Capacity (Litres) 150 180 210 250 300
Diameter (mm) 545 545 545 545 545
Height (mm) A1102 1290 1478 1728 2041
Solar High Limit Thermostat Pocket (mm) B890 1078 1266 1516 1829
Solar Auxillary Pocket (mm) C890 1078 1266 1516 1829
T & P Valve (mm) D890 1078 1266 1516 1829
Secondary Return (mm) E- - 1159 1409 1609
Boiler Dual Stat Pocket (mm) F706 738 843 918 1043
Immersion 1(mm) G702 734 839 914 1039
Top Coil (mm) H651 675 789 863 989
Solar Sensor Pocket (mm) I354 354 429 429 429
Bottom Coil (mm) J299 299 374 374 374
Cold Inlet (mm) K192 192 192 192 192
A
B
C
D
E
F
G
K
H
J
I

AquaFlo Installation, Maintenance and User Instructions Page 9 of 24 V 2.01 - October / 2012
AQUAFLO SOLAR DIRECT DIMENSIONS (FIG. B)
Model AF6150 AF6180 AF6210 AF6250 AF6300
Nominal Capacity (Litres) 150 180 210 250 300
Diameter (mm) 545 545 545 545 545
Height (mm) A1102 1290 1478 1728 2041
Solar High Limit Thermostat Pocket (mm) B890 1078 1266 1516 1829
Solar Auxillary Pocket (mm) C890 1078 1266 1516 1829
T & P Valve (mm) D890 1078 1266 1516 1829
Sec. Return (mm) E- - 1159 1409 1609
Immersion 2 (mm) F619 719 819 959 1109
Immersion 1(mm) G399 454 509 584 679
Solar Sensor Pocket (mm) H354 354 429 429 429
Bottom Coil (mm) I299 299 374 374 374
Cold Inlet (mm) J192 192 192 192 192
A
B
C
D
E
F
G
H
I
J

AquaFlo Installation, Maintenance and User Instructions Page 10 of 24 V 2.01 - October / 2012
Standing
Loss
(kWh/day)
High level
Immersion
Elements
Low level
Immersion
Elements
Boost
re-heat
(Minutes)
Heat up 9kW
(Minutes Apxrox.)
Heat up 6kW
(Minutes Apxrox.)
Heat up 3kW
(Minutes)
Vol within
10oC of Set Temp.
(Litres)
Weight Full
(kg)
Weight
Empty
(kg)
Height
(mm) x 545 Diam.
Storage Capacity
(Litres)
Model
AQUAFLO DIRECT SPECIFICATIONS
1.07
0
1
-
-
-
76.0
73
111
21
727
90
AF3090
1.23
1
1
58.0
-
-
103.0
102
146
26
915
120
AF3120
1.41
1
1
72.0
-
-
134.0
133
183
33
1102
150
AF3150
1.53
1
1
82.0
-
-
164.0
163
218
38
1290
180
AF3180
1.80
1
1
96.0
-
-
203.0
194
251
41
1478
210
AF3210
2.15
1
1
117.0
-
-
248.0
236
296
46
1728
250
AF3250
2.28
1
1
145.0
-
-
323.0
288
355
55
2041
300
AF3300
1.41
0 or 1
3 or 2
72.0#
57
73
134.0
133
183
33
1102
150
AF3150S*
1.53
0 or 1
3 or 2
82.0#
67
88
164.0
163
218
38
1290
180
AF3180S*
1.80
0 or 1
3 or 2
96.0#
80
108
203.0
194
251
41
1478
210
AF3210S*
2.15
0 or 1
3 or 2
117.0#
95
130
248.0
236
296
46
1728
250
AF3250S*
2.28
0 or 1
3 or 2
145.0#
120
168
323.0
288
355
55
2041
300
AF3300S*
* Supplied with 3 elements and 4 bosses - 3 at low level and 1 at high level. Additional elements are available for
installation in the 4th boss. # If using high level element.

AquaFlo Installation, Maintenance and User Instructions Page 11 of 24 V 2.01 - October / 2012
AQUAFLO INDIRECT SPECIFICATIONS
Model
AF4090 AF4120 AF4150 AF4180 AF4210 AF4250 AF4300
Storage Capacity
(Litres) 88 118 148 178 208 248 297
Height
(mm) x 545 Diameter 727 915 1102 1290 1478 1728 2041
Weight Empty
(kg) 23 30 38 42 45 51 60
Weight Full
(kg) 111 148 186 220 253 299 357
Vol Within 10oC of Set Temperature
(Litres) 74 105 132 160 188 232 285
Heat up 14.2 20.0 22.0 26.2 31.2 33.0 41.0
Re-heat (minutes)
Following 70% draw off 12.0 16.0 17.2 20.4 22.0 25.0 34.0
Indirect Heat Exchanger
(kW) 16.46 16.46 18.55 18.55 18.55 22.00 22.00
Boost
re-heat
(Minutes)
- - - - - 117.0 145.0
Low level Immersion
Elements 1111111
High level Immersion
Elements 0000011
Standing Loss
(kWh/day) 1.07 1.23 1.41 1.53 1.80 2.15 2.28

AquaFlo Installation, Maintenance and User Instructions Page 12 of 24 V 2.01 - October / 2012
* Re-heat times based on BS12897 parameters with an 80°C primary ow at 15 l/min.
# Using Indirect heat exchanger.
Actual performance when installed will vary considerably dependant on the rate of solar or other
renewable input, number of panels etc.
AQUAFLO SOLAR COMPATIBLE SPECIFICATIONS
SOLAR TWIN COIL SOLAR DIRECT
Model
AF5150 AF5180 AF5210 AF5250 AF5300 AF6150 AF6180 AF6210 AF6250 AF6300
Storage
Capacity
(Litres)
147 177 207 247 297 148 178 207 248 298
Height
(mm) x 545 Dia. 1102 1290 1478 1728 2041 1102 1290 1478 1728 2041
Weight Empty
(kg) 40 45 48 53 63 38 42 45 51 60
Weight Full
(kg) 187 222 255 300 359 186 220 253 299 358
Volume within 10°C
of Set Temperature
(Litres)
132 160 188 232 285 132 160 188 232 285
Heat up (minutes)
1 x 3kW Immersion 54.1 82.7 97.9 113.9 164.3 114.0 136.8 159.6 182.4 225
Re-heat (minutes)
1 x 3kW Immersion 37.9 57.9 68.5 79.7 115.0 79.8 95.8 111.7 127.7 159.6
Indirect
Heat Exchanger
(kW)
18.55 18.55 22.00 22.00 22.00 - - - - -
Solar Heat
Exchanger
(kW)
16.46 18.55 18.55 22.00 22.00 16.46 18.55 18.55 22.00 22.00
Dedicated Solar
Capacity
(Litres)
50 60 70 90 100 50 60 70 90 100
Recovery
solar
(Minutes)
25.0* 26.3* 31.2* 33.0* 41.0* 25.0* 26.3* 31.2* 33.0* 41.0*
Boost re-heat
(Minutes) 12.0# 14.8# 15.5# 20.0# 25.0# 72.0 82.0 96.0 117.0 145.0
Low level
Immersion
Elements
0000011111
High level
Immersion
Elements
1111111111
Standing Loss
(kWh/day) 1.41 1.53 1.80 2.15 2.28 1.41 1.53 1.80 2.15 2.28

AquaFlo Installation, Maintenance and User Instructions Page 13 of 24 V 2.01 - October / 2012
Item Part. No. Description
1SA20001 Cold Water Inlet Set
2SA20002 15mm x 22mm Tundish
3SA20003 Temperature & Pressure Relief Valve
4
SA20004 Expansion Vessel - 12 Litre (including bracket)
SA20005 Expansion Vessel - 18 Litre (including bracket)
SA20006 Expansion Vessel - 24 Litre (including bracket)
5SA20007 Immersion Heater 3 kW
5SA20015 Immersion Heater 3 kW Titanium (optional)
6SA20008 Immersion Heater Dual Stat
SA20014 Solar High Limit Stat. (Not Shown)
7SA20011 2 Port Valve
SA20013 Non Self Resseting Thermostat (High Limit). (Not Shown)
SA20010 Separate Expansion Vessel Bracket. (Not Shown)
PARTS LIST
Expansion
Vessel with
Wall Bracket
Temperature &
Pressure Relief
Valve
Drain Via Cold Inlet
(not supplied)
Dual
Stat
Tundish
From cold
Inlet Set
take off
DONOTtshutoffvalvebetween
Cylinder and Expansion Valve
Isolating Valve
(not supplied)
Pressure Reducing Valve
Balanced Cold Connection
Non Return Valve
2 Port Valve
Pump
(not supplied)
Secondary
Return
Hot Outlet
Non Return Valve
(not supplied)
Cold
Main
Boiler Flow
Boiler Return
Expansion Relief Valve
1
2
3
4
5
6
7

AquaFlo Installation, Maintenance and User Instructions Page 14 of 24 V 2.01 - October / 2012
INSTALLATION
Installation prerequisites
Zip Aquao should only be installed by a competent installer holding their G3 unvented
qualication. The installation of this product is also notiable under the national building
regulations.
The electrical installation including earthing and cross bonding must comply with the current
IEE regulations and any Local Authority requirements.
Requirements
Zip AquaFlo is capable of delivering over 50 litres per minute when connected to a suitable
mains supply. The high quality inlet control set with its 0.3 MPa (3 bar) operating pressure
has been designed to make the most of what is available, however the performance of any
unvented system is only as good as the water supply.
In unvented systems both hot and cold services are supplied simultaneously from the mains so
the maximum possible on-site water demand must be assessed and the water supply should
be tested to ensure it can meet these requirements.
If necessary consult the local water supplier regarding the likely pressure and ow rate
availability.
It is important that site pressure readings are taken under dynamic ow conditions,
high pressures under zero ow conditions are not necessarily indicative of satisfactory
performance. A minimum of 0.15 MPa (1.5 bar) at 20 l/m ow should be available.
Where mains inlet pressures are likely to exceed 1.2 MPa (12 bar) then an additional upstream
pressure reducing device should be tted.
A minimum of 22mm supply pipe-work should ideally be provided and existing ½” (15mm)
cold mains pipe-work may need to be upgraded. Hard water treatment should be considered in
areas where the calcium carbonate content is greater than 200ppm, if required adjust cylinder
temperature to below 60°C.
This Cylinder should only be installed by a competent installer holding their G3 unvented
qualication. The installation of this product is also notiable under the national building
regulations.
The electrical installation including earthing and cross bonding must comply with the current
IEE regulations and any Local Authority requirements.
Connecting units in parallel
Multiple AquaFlo units can be connected together in parallel for applications where higher
storage capacity is required. To connect in parallel, each AquaFlo should be provided with a
separate cold supply while the hot outlets are connected to a common pipeline.
Secondary return
All AquaFlo units are suitable for use with secondary return systems. A dedicated secondary
return connection is provided with a capacity of 210 litres and above. On smaller sizes the
secondary return can be connected to the incoming supply. Always check that the kW loading
available on direct units is sufcient to recover the heat loss in the secondary circuit in addition
to any hot water drawn off.

AquaFlo Installation, Maintenance and User Instructions Page 15 of 24 V 2.01 - October / 2012
INSTALLATION SITE
Zip AquaFlo can be positioned more or less anywhere in the building but it should be
remembered that for every 1 meter that an outlet is above the AquaFlo, the pressure will be
reduced by 0.01 MPa (0.1 bar). If siting outside the heated envelope of the dwelling such as
in a garage or outbuilding then frost protection should be provided and exposed pipe work
should be insulated.
Zip AquaFlo must be supported on a at base (intended for oor standing) capable of
supporting the weight of the cylinder when full. The minimum recommended cupboard size is
650mm square.
It’s important that consideration is given to access for maintenance of the valves.
The immersion heaters are 375mm long and access space should be provided for possible
future replacement.
INSTALLING THE APPLIANCE
Cylinder connections
All plumbing connections should be made to Zip AquaFlo and its safety devices using the
15mm or 22mm compression ttings, nuts and olives supplied.
Cylinder relief valve connections
Safety relief valve connections should not be used for any other purpose and no valve should be
tted between the expansion relief valve and the storage cylinder.
Cold mains pipework
Run the cold main through the building to the place where the AquaFlo is to be installed. Take
care not to run the cold pipe near hot water or heating pipe work so that the heat pick up is
minimized. Identify the cold water supply pipe and t an isolating valve (not supplied).
A 22mm BS1010 stopcock can typically be used but a 22mm quarter turn full bore valve would
be better as it does not restrict the ow as much. Do not use “screwdriver slot” or similar
valves.
Make the connection to the cold feed of the cylinder and incorporate a drain valve (not supplied).
Position the inlet control just above the Temperature & Pressure Relief Valve (TPRV) mounted
on the side of the cylinder. This ensures that the cylinder does not have to be drained down in
order to service the inlet control set. Ensure that the arrow points in the direction of the water
ow. Select a suitable position for the expansion vessel. Mount it to the wall using the bracket
provided.
A ¾” BSP female x 22mm compression connection is provided to connect the expansion vessel
to the 22mm pipe.
Balanced cold connection
If there are to be showers, bidets or monobloc taps in the installation then a balanced cold supply

AquaFlo Installation, Maintenance and User Instructions Page 16 of 24 V 2.01 - October / 2012
is a requirement. There is a 22mm balanced connection on the inlet control set that must be
used for this purpose.
Hot water pipework
Run the rst part of the hot water distribution pipework in 22mm. This can be reduced to
15 mm and 10 mm as appropriate for the type of tap etc.. Your aim should be to reduce the
volume of the hot draw off pipework to a practical minimum so that the time taken for the hot
water is as quick as possible.
Do not use monobloc mixer tap or showers if the balanced cold connection is not provided. This
arrangement will back pressurise the unit and result in discharge.
Primary coil connections (Indirect Only)
Compression connections are provided for the primary circuit which must be positively pumped.
Primary ow and return connections are interchangeable to suit site conditions without affecting
reheat times.
Sealed or vented primary circuits can be used, to comply with normal installation practice the
primary pressure should not exceed 0.3 MPa (3 bar) although the coil in AquaFlo is suitable for up
to 0.7 MPa (7 bar) if required. The boiler may be Gas, Electric, Oil etc but must be under effective
thermostatic control. Zip AquaFlo is not intended for use with uncontrolled heat sources such as
some AGA’s, back boilers, solid fuel stoves etc. The two port zone valve should be installed into
the primary ow pipework leading to the coil ow inlet. The direction of ow arrow should be
towards the primary ow connection. On twin coil cylinders an extra thermostat boss is provided.
Secondary circulation
Where secondary circulation is required a circulator suitable for wholesome water should be
used in conjunction with a non return valve to prevent back ow.
It may be necessary to incorporate an extra expansion vessel into the circuit to accommodate
the increased system water volume in larger secondary circulation systems. Where off peak
electrical tariffs are being used then secondary circulation should be avoided. A secondary
return boss is tted as standard on 210, 250 & 300 litre. On smaller sizes tee into the cold feed
pipe above the drain.
Immersion heaters
As a requirement of Building regulations the AquaFlo immersion heaters are tted with thermal
cut-out in addition to the normal control thermostat. To help ensure correct replacement the
immersion heaters have a special 1
¾ ” thread. They are of a low noise Incoloy construction and
rated at 3kW at 240V. Replacement immersion heaters should be purchased from Zip Heaters
otherwise the product warranty may be affected. Note! Titanium elements are also available for
areas with aggressive water, constant cycling and high usage. (See parts on page 13).
Undernocircumstancesshouldimmersionheaterswithoutthermalcut-outsbettedto
Zip AquaFlo.
The o-ring on the head of the immersion heater should be correctly positioned and lubricated
before tting. Screw in until hand-tight then gently tighten as the o-ring will seal easily.

AquaFlo Installation, Maintenance and User Instructions Page 17 of 24 V 2.01 - October / 2012
The electrical supply to each immersion heater must be fused at 13A via a double pole isolating
switch to BS 3456. The cable must be 2.5mm2 heat resistant (85°C HOFR) sheathed ex
complying to BS 6141:1981. Do not operate the immersion heater/s until the unit is full of water.
If any sterilisation liquid is in the cylinder do not operate the immersion heater/s as this will
cause premature failure.
The electrical supply must be from a fused supply compliant with local regulations and tted
by a suitably qualied Electrician.
Energy cutout and cylinder thermostat (Indirect Only)
As a requirement of Building regulations the AquaFlo units are tted with a thermal cut-out in
addition to the normal control thermostat. This unit should be tted to the dedicated boss on
the cylinder and wired to the two port valve controlling the primary ow (see wiring diagram).
AquaFlo unvented indirect Twin coil solar
Indirect twin coil units can be installed in two separate formats:
1. In a solar powered system with a fossil fuel boiler.
2. In a system with two independent fossil fuel boilers.
With either format it is essential the overall installation meets all current legislation including,
in particular, the high limit isolation requirements of Building Regulation G3. This document is
designed to assist in achieving this aim.
Upper coil
The upper coil is connected to the fossil fuel boiler as per the instructions for the AquaFlo single
coil model with the Dual Control thermostat inserted into the middle stat pocket. The wiring
requirements are as depicted in this guide.
Lower coil: Solar Installation
In a solar powered system the lower coil is connected to the solar heat source. Either primary
coil connection may be utilised as the ow or return. The solar cylinder sensor, supplied as part
of the solar controls, inserts into the lower stat pocket with the supplied grommet. It is necessary
to mount the solar pump in the return pipework with the two port valve (supplied with the
cylinder) installed between the cylinder and the pump.
This valve is of the powered open, sprung closed design and is wired through the high limit stat
which inserts into the upper stat pocket. Two wiring options for high limit isolation are provided
in this guide. The control thermostat is not required in a solar installation.
The remaining upper stat pocket is for the use of a sensor often supplied with a solar control
package which may then provide via display on the solar control panel indication of the water
temperature in the cylinder. NB: not all solar control packs provide this facility.
Lower coil: Two Boiler Installation
Where the lower coil is to be used with a fossil fuel boiler, the pipework requirements are as
per that of a Stainless Indirect single coil cylinder described earlier in this book. However the
electrical requirements mean the control thermostat inserts into the lower tank stat pocket to
control the boiler input and the limit stat into the upper tank stat pocket. The two port valve may
be installed into either the ow or return pipework. Wiring of the controls are as per the wiring
diagram in this guide.

AquaFlo Installation, Maintenance and User Instructions Page 18 of 24 V 2.01 - October / 2012
Discharge arrangement
General guidance is provide by the diagram on page 19, extracted from the G3 Building
Regulation Guidance. This guidance is available as a free of charge download of the G3
Approved Document from www.planningportal.gov.uk.
The discharge from both the Temperature relief and expansion relief valves can be joined
together via a 15mm end feed Tee.
It is important that any discharge water does not collect in this pipe-work and can run freely to
the tundish. The tundish should be mounted in a vertical and visible position located in the same
space as the unvented hot water storage system and be tted as close as possible and within
600mm of the safety device e.g. the temperature relief valve. The discharge pipe-work from the
tundish must be routed in accordance with Part G3 of the Building Regulations.
The discharge pipes and tundish should be installed in a visible location away from any electrical
devices, should terminate in a safe place where there is no risk to persons in the vicinity of the
discharge, be of metal and:
• Be at least one pipe size larger than the nominal outlet size of the safety device unless its
total equivalent hydraulic resistance exceeds that of a straight pipe 9m long i.e. discharge
pipes between 9m and 18m equivalent resistance length should be at least two sizes
larger than the nominal outlet size of the safety device, between 18 and 27m
at least 3 sizes larger, and so on. Bends must be taken into account in calculating the
ow resistance.
An alternative approach for sizing discharge pipes would be to follow BS6700
Specication for design installation, testing and maintenance of services supplying water
for domestic use within buildings and their curtilages.
• Have a vertical section of pipe at least 300mm long, below the tundish before any elbows
or bends in the pipework.
• Be installed with a continuous fall.
• It is preferable for the discharge to be visible at both the tundish and the nal point of
discharge but where this is not possible or practically difcult there should be clear
visibility at one or other of these locations.
Examples of acceptable discharge arrangements are:
• Ideally below the xed grating and above the water seal in a trapped gulley.
• Downward discharges at a low level; i.e. up to 100mm above external surfaces such as
car parks, hard standings, grassed areas etc. are acceptable providing that a wire cage or
similar guard is positioned to prevent contact whilst maintaining visibility.
• Discharges at a high level; e.g. in to metal hopper and metal down pipe with the end of
the discharge pipe clearly visible or onto a roof capable of withstanding high temperature
discharges of water and 3m from any plastic guttering systems that would collect such
discharges.