Mixergy 90 User guide

Installation and servicing instructions MDC0001
For stainless steel hot water cylinders
Failure to install and maintain this system in accordance with
these instructions will invalidate the manufacturer’s warranty.
Please leave with householder
Mixergy Ltd
2 Canal View
Wharf Farm
Cassington
Oxfordshire
OX29 4DB
V14 07/04/21
®

2
Cylinder details
Technical data
MX number
Your cylinder MX number can be found on the label placed on the front of the cylin-
der.
For all queries, please contact us:
Tel: [phone]
E-Mail: [e-mail]
Max. supply pressure to pressure reducing valve 1 MPa (10 bar)
Operating pressure 0.3 MPa (3 bar)
Expansion vessel charge pressure 0.3 MPa (3 bar)
Expansion relief valve setting 0.6 MPa (6 bar)
P&T relief valve setting (pressure) 0.7 MPa (7 bar)
P&T relief valve setting (temperature) 90 °C
Adjustable temperature range (digital) 50 - 65 °C
Coil max. working pressure (indirect) 0.35 MPa (3.5 bar)
Immersion heater(s) rating 230-240 V~ 2.7-3.0 kW
Immersion heater(s) specification EN 60335-2-73
Immersion heater(s) type 356 mm Incoloy
Thermostat cut-out temperature 80 °C

Contents
Cylinder details 2
Technical data 2
Contents 3
About your cylinder 4
Additional components 5
Model specifications 5
Model specifications 6
Design notes 7
Schematic: Direct 8
Schematic: Indirect/Lite 9
Schematic: Heat pump 10
Installation: general guidelines 12
Installation: electrical 15
Installation: connectivity 22
Discharge pipework 23
Commissioning 28
Commissioning checklist 31
Problem solving 33
Draining the cylinder 35
Replacement parts 35
Servicing 36
Service record 37

4
About your cylinder
The Mixergy cylinder is a hot water storage cylinder which uses
thermal stratification on charge (direct and indirect) and dis-
charge (direct, indirect, lite and heat pump).
This stratification technology allows the Mixergy cylinder to par-
tially heat (or ‘charge’) the water, reducing heat losses, improving
available renewable capacity and allowing for exploitation of smart
tariffs.
For more information on how your cylinder works and how to get
the most out of your system, please refer to the user guide.
15 ˚C
55 ˚C
15 ˚C
55 ˚C

5
Additional components
• Monobloc kit incl. pressure reducing valve, check valve, pres-
sure and temperature relief valve and expansion relief valve
• Tundish
• Expansion vessel incl. mounting bracket and 3/4” x 22mm
adapters
• 3 kW immersion heater(s) 1.3/4” BSP (fitted)
• High limit thermostat (indirect only, fitted)
• 2-port diverter valve V4043H1056 (indirect only)
• Powerline to ethernet adapter TL-PA4010
• Ethernet cable
• User guide
Model specifications
*For heat pump systems with external heat exchangers fitted, add
2 kg to the cylinder weight.
Cylinder
model 90 120 150 180 210 300
Nominal
dia. (mm) 478 478 580 478 580 478 580 478 580 580
Cylinder
height
(mm)
1141 1329 1050 1517 1236 1767 1418 2081 1608 2125
Empty weights (kg)*
Direct 23 28 32 35 37 38 42 40 47 57
Indirect /
Lite -- 32 37 40 42 44 47 47 52 62
Full weights (kg)*
Direct 113 148 162 185 187 218 217 250 262 362
Indirect /
Lite -- 152 167 190 192 224 222 257 267 367

6
Model specifications
Cylinder
model 90 120 150 180 210 300
Nominal dia.
(mm) 478 478 580 478 580 478 580 478 580 580
Minimum
reheat time
(15 to 65 °C) -
Direct
30 min 30
min
44
min
30
min
44
min
30
min
44
min
30
min
44
min 44 min
Minimum
reheat time
(15 to 65 °C) -
Indirect
12 min
70% charge
reheat time
(15 to 65 °C) -
Direct
73 min 98 min 123 min 147 min 172 min 245 min
70% charge
reheat time
(15 to 65 °C) -
Ind / Lite
-- 14 min 17 min 21 min 23 min 31 min
70% charge
reheat time
(15 to 65 °C)
- HP
4 min 6 min 7 min 9 min 10 min 14 min
100% charge
reheat time
(15 to 65 °C) -
Direct
105 min 140 min 176 min 210 min 246 min 350 min
100% charge
reheat time
(15 to 65 °C) -
Ind / Lite
-- 20 min 25 min 30 min 33 min 45 min
100% charge
reheat time
(15 to 65 °C)
- HP
6 min 9 min 11 min 13 min 15 min 21 min
Lite and heat pump variants do not stratify on charge and
thus only produce useful hot water when charging to a
minimum of 70%

7
Design notes
The Mixergy cylinder is currently available in four basic variations:
• Mixergy Direct - Provides hot water heated by electricity and is
designed primarily for use with off peak electricity.
• Mixergy Indirect / Lite - Provides hot water either by electricity
or an internal primary coil which is designed for use with elec-
tric, gas or oil fired boilers.
In addition, Mixergy cylinders can be fitted with the following op-
tions:
• Dual primary element for use with a third-party PV diverter.
• Embedded PV diverter.
• Heat pump exchanger module for use with heat pumps.
The unit should be handled with care in order to avoid damage. It
should be stored upright in a dry place.
Unvented hot water cylinders must not be used with
solid fuel boilers as the energy source.
All models are factory fitted / supplied with immer-
sion heaters that have built-in thermal cut-outs. Im-
mersion heaters without thermal cut-outs must not
be fitted.
All unvented installations must be fitted with a pres-
sure reducing valve (supplied) and P&T relief valve
(fitted). These must not be removed or used for any
other purposes than what they are designed for.

8
Schematic: Direct
12
1
2
9
8
6
5
4
3
10
12
13
11
1Controller Cold water control monobloc
Cold feed Expansion vessel
Hot draw Heat pump exchanger ports
Primary immersion Tundish and discharge pipe
External probe pocket Pump assembly
P&T valve Cold inlet
-- --
2
3
4
5
6
7
8
9
10
11
12
13
14

9
Schematic: Indirect/Lite
Lite cylinder
variants will
have a lower coil
position and no
pump assembly
or backup
immersion fitted
2
1
9
8
6
7
5
4
3
10
12
13
11
1Controller Cold water control monobloc
Cold feed Expansion vessel
Hot draw Heat pump exchanger ports
Primary immersion Tundish and discharge pipe
External probe pocket Pump assembly
P&T valve Cold inlet
Indirect coil feed/return --
2
3
4
5
6
7
8
9
10
11
12
13
14
7

10
coil or exchanger feed
Indirect/external exchanger units
2-port valve*
Indirect feed
Indirect return
Mixergy cylinder
Hot draw
P&T relief valve
Tundish Discharge pipe
*2-port valve MUST be fitted for heat sources with flow temperatures exceeding 65°C
Drain cock
Expansion vessel
Isolating valve
Cold feed
Cold water control monobloc valve
Check valve
StrainerPressure
reducing valve
Pressure relief valve

11
Installation: general guidelines
The installation area should be able to cope with the weight, in-
coming pipes and discharge pipe when full. Full weights are listed
on page 5 of this booklet.
Positioning of the cylinder
Position of the cylinder should suit the installation; all connections
should be to the front for ease of access. Ensure suitable space is
left for access for repair and/or replacement of immersions and
valves etc. Ensure at-least 300mm of vertical clearance above
the cylinder. Refer to page 5 for cylinder heights and the dia-
gram below for guidelines on space requirements:
Nominal di-
ameter nD
(mm)
Space re-
quirement S
(mm)
470-480 580
In the case of an unvented installation, install of this
product should only be carried out by a “competent
operative” i.e. the installer must have attended a
recognised course in unvented hot water systems or
received appropriate training in their apprenticeship.
All registered operatives should carry an Identifi-
cation Card issued by the institute of Unvented Hot
Water Systems.
550-580 700
S
S
�D
Ensure that any
apertures (such as
loft hatches) that
the cylinder must
pass through, meet
the minimum space
requirement S.

12
Installation: general guidelines
Unvented installations
In the case of an unvented installation, installers should ensure
incoming mains pressure is less than 1 MPa (10 bar) and at-least 0.1
MPa (1 bar) with a minimum flow rate of 5 L/min. Local authority
approval for installation of unvented systems must be granted.
Use of flux and sterilisation
Excessive use of flux can damage the unit and especially the valves
and expansion vessel (if supplied). Avoid over-use and ensure the
system is fully flushed of any debris or flux after connection. If a full
sterilisation of all the pipework including the cylinder is required
then a complete drain down and flush of the unit is essential. A
simple flush through with water is not adequate in removing all
sterilising solution within the cylinder. Under no circumstances
should sterilising solution be left in the cylinder any longer than re-
quired (seek dosage requirements from chemical manufacturer).
Pipework and cold water control group
The unit should be piped in with a nominal 22mm pipe to ensure
adequate flow rate. The unit is supplied with a monobloc pressure
reducing valve that has a set pressure of 3.0 bar. The valve also
consists of a serviceable strainer, non return valve, expansion relief
valve, connection for an expansion vessel and balanced cold feed
supply. We would strongly recommend fitting an isolating valve
(not supplied) prior to the monobloc valve for ease of maintenance
at a later date. Under no circumstances should an isolating valve
be fitted between the expansion valve and the storage cylinder.
Fitting a drain valve
Please ensure that a drain valve is fitted to the lowest part of the
unit, The drain valve must be fitted as low as possible so that at
least 80% of the cylinder’s total capacity can be drained off.
Connecting the hot draw
It is recommended that a 90° elbow be fitted within 100 mm of
the hot draw to minimize heat losses due to thermosiphoning.

13
Installation: general guidelines
The relief valves are only to be used for relief dis-
charge purposes. No valves should be fitted between
the relief valves and the cylinder.
Indirect units and electrical wiring
On Indirect Units, where a coil is fitted to the cylinder, the supplied
two port motorized zone valve must be fitted in accordance with
the instruction details supplied for the appropriate installation.
Maximum working pressure of the coils is 3.5 Bar. All electrical
wiring to electronics, zone valve and immersion heaters must be
earthed and to current IEE Wiring Regulations.
Positioning the tundish
The tundish, which shows visible discharge from the relief valves, is
to be in a prominent, visible and safe position away from any elec-
trical devices. See discharge and safety devices on page 26.
Checking the P&T relief valve
The pressure and temperature relief valve is set at 7 bar and 90°C
and is factory fitted and sealed prior to dispatch. Whilst we en-
deavour to make sure there are no leaks from the seal, we would
advise checking the connection as the valve may have been dis-
rupted in transit.
Fitting the expansion vessel
The expansion vessel should be checked and if required charged
at 3.0 bar. The vessel should be mounted securely to the wall or
sufficient support with the fixing kit supplied. The connection
should be made between the vessel and monobloc kit.
The electrical supply to the controller and any addi-
tional immersion heaters must be installed by a quali-
fied electrician.

14
Installation: electrical
External wiring
Mixergy cylinders come supplied with cable included. The pur-
pose and installation requirements for each cable are given below.
Layout of the internal junctions within the controller are also given
should replacement cables be required.
Supply
The white 3-core (L,N,E) cable labelled ‘supply’ must be connected
to the household’s peak supply via a dedicated 16A MCB protected
circuit with a 20A DP switch. This is the primary power supply for
the control electronics and is used to power the immersion when
the cylinder is set to heat in direct mode.
Timer control
The black 3-core (L,N,E) cable labelled ‘timer control’ can be used
to integrate the Mixergy cylinder with any existing timers or con-
trollers i.e. economy 7 timer or a hive controller. See ‘External con-
troller wiring’ on page 18 for more details on wiring in an exter-
nal controller. This cable detects a 240VAC signal and instructs the
cylinder to heat unless otherwise disabled in software.
Indirect control
The white 4-core (COM, NO, NC, E) cable labelled ‘indirect control’
can be used to provide an indirect control signal for the purpose
of making a call for heat to a boiler/heat pump. When the cylinder
makes a call for heat in indirect/heat pump mode, the controller
will switch the incoming supply at COM from NC to NO. This signal
can be a maximum of 240VAC, 13A. For further details on indirect
wiring please refer to “Indirect wiring” on page 15. For further
details on heat pump wiring, please refer to manual MDC0008.
ENSURE ALL ELECTRICAL SUPPLIES ARE SWITCHED
OFF BEFORE MAKING ANY CONNECTION TO THE
UNIT. ELECTRICAL INSTALLATION MUST BE CARRIED
OUT BY COMPETENT ELECTRICIAN AND BE IN AC-
CORDANCE WITH THE LATEST I.E.E. REGULATIONS.
Both the timer control cable and indirect control
cable are attached to volt free contacts within the
controller and can be safely left tucked away if not
required.

15
Installation: electrical
Indirect wiring
Mixergy indirect cylinders can be wired into both S-plan and
Y-plan heating configurations. Please use the following instruc-
tions for reference.
These instructions are given as a generic reference,
specific timer/smart controller and central heating
valve wiring may vary.
Indirect and external controller wiring
Indirect cylinders are wired via the cable labelled ‘indirect control’.
Full schematics are given on page 16 and page 17. All
conductors of this cable must be safely terminated when
an indirect installation is made. If a direct installation is made
it is recommended to leave this cable tucked away in case it is
required for a subsequent heat pump installation.
Wiring with 2 port zone valve (S-plan)
• Connect a 3A fused supply live to the indirect control cable
BLACK.
• Connect 3A supply neutral to both valves BLUE.
• Connect 3A supply earth to the indirect control cable YELLOW/
GREEN.
• Connect the 2 port valve BROWN cable to the indirect control
cable BROWN.
Wiring with 3 port mid position valve and 2 port zone valve
(Y-plan)
• Connect a 3A fused supply live to the indirect control cable
BLACK.
• Connect 3A supply neutral to both valves BLUE.
• Connect 3A supply earth to the indirect control cable YELLOW/
GREEN.
• Connect the 2 port valve BROWN cable to the indirect control
cable BROWN.
• Connect the 3 port valve GREY cable to the indirect control
cable GREY.
• Connect the 3 port valve ORANGE cable to the 2 port valve
ORANGE cable.

16
Installation: electrical (S-PLAN)
L N E
MIXERGY INDIRECT
CONTROL CABLE
SINGLE* CHANNEL
TIMER CONTROLLER
N
L
1
2
3
4
BLACK
GREEN
GREEN
GREEN
BLUE
BLUE
WHITE
WIRING CENTRE
WHITE
BROWN
BROWN ORANGE
TO BOILER SL
DHW 2-PORT
HEATING 2-PORT
BROWN ORANGE
TO 10
L
N
E
SL
3A FUSED SUPPLY
BOILER
12345678910
2 PORT VALVE
(DHW)
SINGLE* CHANNEL
TIMER CONTROLLER
INDIRECT CONTROL
CABLE
2 PORT VALVE
(HEATING)
3A SUPPLY
PROTECTIVE EARTH
PROTECTIVE EARTH
PROTECTIVE EARTH
WIRING CENTRE (NOT SUPPLIED)
BOILER/INDIRECT SOURCE
INDIRECT RELAY
HIGH LIMIT STAT
MIXERGY FACTORY WIRING
PERM. LIVE
GND
P.E
P.E
N
L
1
2
3
4
BLACK
GREEN
BROWN
GREY
S-PLAN SCHEMATIC VIEW
S-PLAN PICTORAL VIEW
*In the case of a dual channel timer controller, connect timer terminal 4 to terminal 5 of the wiring centre. Connect terminal 3 to timer control cable if required (page 18)

17
L N E
MIXERGY INDIRECT
CONTROL CABLE
SINGLE* CHANNEL
TIMER CONTROLLER
N
L
1
2
3
4
BLACK
GREEN
GREEN
GREEN
BLUE
BLUE
WHITE
WIRING CENTRE
WHITE
BROWN
BROWN ORANGE
TO BOILER SL
DHW 2-PORT
HEATING 2-PORT
BROWN ORANGE
TO 10
L
N
E
SL
3A FUSED SUPPLY
BOILER
12345678910
2 PORT VALVE
(DHW)
SINGLE* CHANNEL
TIMER CONTROLLER
INDIRECT CONTROL
CABLE
2 PORT VALVE
(HEATING)
3A SUPPLY
PROTECTIVE EARTH
PROTECTIVE EARTH
PROTECTIVE EARTH
WIRING CENTRE (NOT SUPPLIED)
BOILER/INDIRECT SOURCE
INDIRECT RELAY
HIGH LIMIT STAT
MIXERGY FACTORY WIRING
PERM. LIVE
GND
P.E
P.E
N
L
1
2
3
4
BLACK
GREEN
BROWN
GREY
S-PLAN SCHEMATIC VIEW
S-PLAN PICTORAL VIEW
WIRING CENTRE
MIDPOS 3-PORT
L NE
MIXERGY INDIRECT
CONTROL CABLE
SINGLE* CHANNEL
TIMER CONTROLLER
N
L
1
2
3
4
BLACK GREY
GREEN
GREEN
GREEN
BLUE
BLUE
WHITE
GREY
BROWN
BROWN ORANGE
TO BOILER SL
DHW 2-PORT
WHITE ORANGE
TO 10
L
N
E
SL
3A FUSED SUPPLY
BOILER
12345678910
INDIRECT CONTROL
CABLE
BLACK
GREEN
BROWN
GREY
Y-PLAN SCHEMATIC VIEW
Y-PLAN PICTORAL VIEW
PROTECTIVE EARTH
BOILER/INDIRECT SOURCE
INDIRECT RELAY
HIGH LIMIT STAT
MIXERGY FACTORY WIRING
2 PORT VALVE
(DHW)
3A SUPPLY
PROTECTIVE EARTH
P.E
P.E
PROTECTIVE EARTH
PERM. LIVE
GND
WIRING CENTRE (NOT SUPPLIED)
3 PORT VALVE
SINGLE* CHANNEL
TIMER CONTROLLER
N
L
1
2
3
4
Installation: electrical (Y-Plan)
*In the case of a dual channel timer controller, connect timer terminal 4 to terminal 5 of the wiring centre. Connect terminal 3 to timer control cable if required (page 18)

18
Installation: electrical
External controller wiring
Mixergy systems can be connected to an external controller using
the timer control cable as follows:
• Connect the brown (L) cable to the external controller ‘DHW
ON’ junction.
• Connect the blue (N) cable to external controller neutral.
• Connect the yellow/green (E) cable to ground.
The timer control cable should only be connected
when the user does not wish to control their system
using the Mixergy app. The timer control cable is not
required if the user wishes to control via. the Mixergy
app.
3-5A SUPPLY
EN LLNE
Mixergy Solar PV

19
Installation: electrical
PV diverters
If your Mixergy cylinder is equipped for use with a third-party PV
diverter, a dual immersion will be fitted to replace the primary im-
mersion shown in the schematics on page 8 and page 9.
This immersion will come factory wired into the Mixergy system
with an additional 3-core (L+N+E) cable labelled ‘solar feed’ that
should be wired into your PV diverter as specified by the manu-
facturer. If a replacement cable is required, please use the wiring
diagram below for reference.
Ensure both supplies are isolated before performing
work. Check continuity between immersion contacts
before wiring. DO NOT CONNECT SOLAR PV AND
MAINS LIVE OR NEUTRAL TOGETHER.
EN
LL
NE
Mixergy Solar PV

20
Installation: connectivity
Installing the powerline adapter
The Mixergy cylinder requires internet connectivity to allow for full
control of the system. Connection to the cylinder can be made
using the provided ethernet to powerline adapter.
If an existing HomePlug AV powerline network is
installed at the property, it is recommended to pair
the cylinder with the existing network to avoid inter-
ference problems as per page 29. Powerline con-
nectivity between the cylinder and internet router is
only possible in houses where both the cylinder and
adapter are powered from the same electrical phase.
1. Plug the powerline adapter into a wall socket within 2m of the
internet router.
2. Plug the powerline adapter into the internet router using the
included 2m ethernet cable.
1
2