mitsubishi electric pre-plumbed unvented mains pressure

MITSUBISHI ELECTRIC PRE-PLUMBED UNVENTED MAINS PRESSURE WATER HEATER
WITH FTC-5 CONTROL SYSTEM FOR USE WITH THE ECODAN
AIR SOURCE HEAT PUMP RANGE
150, 170, 210, 250 and 300 LITRE CAPACITY STANDARD MODELS
210, 250 and 300 LITRE CAPACITY SOLAR MODELS
150 and 170 LITRE CAPACITY SLIMLINE MODELS
IMPORTANT: PLEASE READ AND UNDERSTAND THESE INSTRUCTIONS
BEFORE COMMENCING INSTALLATION. PLEASE LEAVE THIS MANUAL
WITH THE CUSTOMER FOR FUTURE REFERENCE.
1
CONTENTS
INTRODUCTION.....................................................................................................................................2
GENERAL REQUIREMENTS.................................................................................................................4
INSTALLATION – GENERAL.................................................................................................................14
INSTALLATION - DISCHARGE..............................................................................................................17
INSTALLATION - HEAT PUMP PRIMARY CIRCUIT..............................................................................20
INSTALLATION - SOLAR PRIMARY......................................................................................................29
INSTALLATION - IMMERSION HEATER ELECTRICAL SUPPLY.........................................................30
COMMISSIONING..................................................................................................................................31
MAINTENANCE.....................................................................................................................................33
FAULT FINDING & SERVICING.............................................................................................................35
SPARE PARTS.......................................................................................................................................35
USER INSTRUCTIONS..........................................................................................................................38
ENVIROMENTAL INFORMATION..........................................................................................................40
TECHNICAL SUPPORT.........................................................................................................................40
INTRODUCTION
This range of factory pre-plumbed and wired unvented water heaters specifically designed for use with the Mitsubishi Ecodan
Air Source Heat Pump range. The cylinder is manufactured in the UK from top quality materials and meets all the latest relevant
safety and constructional standards. The high grade Duplex stainless steel cylinder offers exceptional strength and corrosion
resistance. Its performance, control system and insulation levels exceed the latest requirements of Building Regulation Part L.
The unvented water heater can be fed directly from the cold water mains supply to the property without the need for separate
feed cisterns or vent pipes. It is supplied fitted with all its necessary inlet and safety controls for compliance with Building
Regulations. Also fitted are primary circulating pumps, a DHW circulation pump, primary to DHW plate to plate heat exchanger,
3 way diverter valve, automatic air vent, primary filling loop and pressure gauge, a cylinder thermal cut-out and Mitsubishi
Electric FTC5 controller. The pumps, motorised valve and thermal controls are supplied pre-wired. A heating and domestic hot
water programmer, The DHW expansion vessel is supplied loose for installation at a convenient position within the property.
An electric immersion heater is also fitted to enable the unit to be heated should the heat pump require supplmentary heating
or be turned off.
NOTE: If using a sealed heating system, adequate provision for expansion within the primary circuit MUST be provided by
fitting a primary circuit expansion vessel. Primary circuit expansion cannot be accommodated within the Air Source Heat
Pump cylinder. Ensure a primary circuit expansion relief valve is fitted to the primary circuit.
The safety valves fitted to the Air Source Heat Pump cylinder protect the water heater only. Failure to provide adequate
primary system pressure relief when using a sealed heating system will invalidate the Heat Pump warranty. Consult the Heat
Pump installation instructions for further advice.
2
IMPORTANT NOTE TO THE INSTALLER
The pre-plumbed cylinder is specifically designed to be installed in conjunction with an air source heat pump. The pre-plumbed
cylinder is available in either STANDARD, SOLAR or SLIMLINE models.
Please read these instructions before commencing installation. Unvented cylinders are a controlled service as defined
inthe latest edition ofthe building regulations and should only be carried out by a competent, qualified installer. The relevant
regulations are:
England and Wales - Building Regulation Part G Section G3
Scotland - Technical Standard Section 4
Northern Ireland - Building Regulation Part F
After installation the Benchmark log book and included commissioning sheets must be completed and left along with thes
instructions with the householder for future reference.
Any water distribution and central heating installation must comply with the relevant recommendations of the current version
of the Regulations and British Standards listed below:
Building Regulations
IEE Requirments for Electrical Installations (BS 7671)
Water Regulations
Manual Handling Operations Regulations
British Standards BS6798, BS5449, BS5540:1, BS5540:2, CP331:3, BS8558, BS7593 and BS7671
Health and Safety Document No. 635
Only qualified and/or competent individuals should install the Ecodan system. Mitsubishi Electric’s notes must not be taken
as overriding statutory obligations.
An annual inspection of the system will be required to ensure safe, long term operation.
The information in this manual is provided to assist generally in the selection of equipment. The responsibility for the selection
and specification of the equipment must however, remain with the installer and any designers or consultants concerned
with the design, specification and installation of the system. Please note: Mitsubishi Electric does not therefore accept any
responsibility for matters of design, selection or specification or for the effectiveness of an installation containing one of its
products unless specifically requested to do so and expressly agreed in writing by Mitsubishi Electric at production stage.
All goods are sold subject to Mitsubishi Electric’s Terms and Conditions of Sale.
Important Note: Included with the Ecodan product is the Mitsubishi Electric user guarantee registration card. Please direct
the end user to register within 3 months of commissioning and ensure they benefit from the applicable standard guarantee
for their Ecodan heat pump and any cylinder or interfacing equipment purchased from Mitsubishi Electric by you as installer.
The guarantee applies where the installation address is in England, Scotland or Wales only and for domestic use.
This registration card should be completed only by the end user/system owner so please ensure that the registration card
reaches them. The registration card is Free Post and is logged by our warranty department. In the unlikely event of failure
of the Ecodan heat pump or any such cylinder or interfacing equipment purchased from Mitsubishi Electric, return of the
card ensures that warranty claims are hassle free. For further information on the Mitsubishi Electric User Guarantee please
contact us by email: ecodan.service@meuk.mee.com or telephone: 0161 866 6064. A sample of the Mitsubishi Electric User
Guarantee registration card is available on request and we can also provide an FAQ sheet to assist your users.
Please Note: If you do not complete and return the registration card then the product will only be guaranteed to the user by
Mitsubishi Electric for 12 months from the date of commissioning.
Our commercial guarantee to your user does not affect your user’s statutory rights or any consumer rights under applicable
national legislation.
3
GENERAL REQUIREMENTS
IMPORTANT: 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 SUPERVISORY 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.
WARNING: Do not switch on if there is a possibility that the water in the heater is frozen.
COMPONENT CHECK LIST
Before commencing installation check that all the components for your Air Source Heat Pump cylinder are contained in the
package. The following components are supplied with your unit :
• Factory fitted
Temperature and Pressure Relief Valve (set at 90°C/10bar)
Immersion heater and over-temperature cut-out
Expansion core unit (comprises expansion valve and check valve)
Tundish
Primary circulating pump (Low Loss Header to Heat Pump return)
Primary circulating pump (Low Loss Header to Heating circuit)
DHW circulating pump
3 Way motorised diverter valve
Primary to DHW plate to plate heat exchanger
Fernox TF1 Compact Magnetic filter
Automatic bypass valve (supplied loose)
Primary circuit filling loop
Primary circuit pressure gauge
Automatic air vent
FTC5 Controller
Solar over-temperature thermal cutout (Solar models only)
• Supplied loose
Mitsubishi Electric CH/DHW Main Controller
Potable water expansion vessel
Cold water combination valve (comprises pressure reducing valve, strainer, check valve)
Automatic differential pressure bypass valve
SITING THE UNIT
The Pre-plumbed cylinder unit must be vertically floor mounted. It can be placed anywhere convenient provided the discharge
pipe(s) from its safety valves can be correctly installed and all pre-fitted ancillary parts can be accessed for servicing and/or
maintenance. Areas that are subject to freezing must be avoided. Ensure that the floor is of sufficient strength to support the
“full” weight of the unit (Table 1, page 5). Pipe runs should be kept as short as possible for maximum economy.
Additional automatic air vents (AAV) (not supplied) may be required at high points in the primary system where pipework is
located above the level of the cylinder.
WATER SUPPLY
Bear in mind that the water supply to the property will be supplying both the hot and cold water requirements simultaneously.
It is recommended that the maximum water demand is assessed and the water supply checked to ensure this demand can
be satisfactorily met.
NOTE: A high water pressure will not always guarantee high flow rates.
Wherever possible the cylinder supply pipe should be 22mm. We suggest the minimum supply requirements should be 1.5
bar pressure and 20 litres per minute flow rate. However, at these values outlet flow rates may be poor if several outlets are
used simultaneously. The higher the available pressure and flow rate the better the system performance.
The cylinder has an operating pressure of 3.5 bar which is controlled by the cold water combination valve assembly. The cold
water combination valve assembly can be connected to a maximum inlet pressure of 16 bar.
4
OUTLET/TERMINAL FITTINGS (TAPS, ETC.)
The Pre-plumbed cylinder can be used in conjunction with most types of terminal fittings, plumbing fittings and pipework.
However, the rated pressures of any fittings selected should be checked for compatibility before installation.
NOTE: Accessories, plumbing fittings and pipework should have a rated operating pressure of at least 8 bar.
Outlets situated higher than the cylinder will give outlet pressures lower than that at the unit, a 10m height difference
will result in a 1 bar pressure reduction at the outlet fitting.
LIMITATIONS
The Pre-plumbed cylinder should not be used in association with any of the following:
• Solid fuel boilers or any other boiler in which the energy input is not under effective thermostatic control, unless additional
and appropriate safety measures are installed.
• Ascending spray type bidets or any other class 1 back syphonage risk require that a type A air gap be employed.
• Steam heating plants unless additional and appropriate safety devices are installed.
• Situations where maintenance is likely to be neglected or safety devices tampered with.
• Water supplies that have either inadequate pressure or where the supply may be intermittent.
• Situations where it is not possible to safely pipe away any discharge from the safety valves.
• In areas where the water consistently contains a high proportion of solids, e.g. suspended matter that could block the
strainer unless adequate filtration can be ensured.
OPERATIONAL SUMMARY
Maximum mains supply pressure
Operating pressure
Expansion vessel pressure
Expansion relief valve setting
T&P relief valve setting
Maximum primary circuit pressure
Storage capacity
Weight when full
1.6 MPa (16 bar)
0.35 MPa (3.5 bar)
0.35 MPa (3.5 bar)
0.8 MPa (8 bar)
90°C/1.0 MPa (10 bar) PTEM 510003
0.3 MPa (3 bar)
See Table 1 below
See Table 1 below
OUTLINE SPECIFICATIONS
Outer casing: White pre-painted corrosion resistant steel
Water container: Duplex stainless steel. 100% pressure tested to 1.5 MPa (15 bar).
Thermal insulation: CFC/HCFC free fire retardant expanded polyurethane foam with zero ozone depletion potential. It has a
Global Warming Potential (GWP) of 3.1. Nominal thickness Standard and Solar units 60mm, Slimline units 50mm.
Table 1 - Unit Weights & Standing Heat Loss
Nominal
Capacity
(litres)
Weight of
full unit (kg)
Weight of
unit (kg)
per day (kWh/24h)
per year (kWh/365d)
Standard
150
206
56
1.19
434.4
Standard
170
232
62
1.32
481.8
Standard
210
279
69
1.57
573.1
Standard
250
327
77
1.67
609.6
Standard
300
387
87
1.89
689.9
Solar
210
284
74
1.56
569.4
Solar
250
332
82
1.63
595.0
Solar
300
392
92
1.84
671.6
Slimline
150
204
54
1.45
529.3
Slimline
170
230
60
1.63
595.0
Model Type
Standing Heat Loss
5
Fig 1 - Parts identification
How Water Outlet
Magnetic filter
FTC5 Controller
Expansion Valve
Automatic Air Vent
Low loss header
3 Way motorised
diverter valve
Primary circuit
pressure gauge
Primary circulation
pumps
Immersion heater
housing
Flow sensor
Temperature/Pressure
Relief Valve
Tundish
DHW circulating
pump
Expansion vessel
tapping
Scale Trap
Plate to Plate heat
exchanger
DHW Drain off
point
Primary circuit
drain off point
Solar coil connections
(Solar models only)
6
Solar controls housing
(Solar models only)
Fig 2a - Dimensions - Standard models
Ø 579
691
A
B
D
C
712
E
KEY
A
B
C
D
E
F
F
OVERALL HEIGHT
HEAT PUMP FLOW CONNECTION
TUNSISH OUTLET CONNECTION
HEAT PUMP RETURN CONNECTION
HEATING CIRCUIT FLOW CONNECTION
HEATING CIRCUIT RETRUN CONNECTION
CAPACITY
150
170
210
250
300
A
1113
1239
1491
1743
2057
B
1000
1000
1000
1000
1000
C
493
619
871
1123
1437
D
589
589
589
589
589
E
199
199
199
199
199
F
54
54
54
54
54
7
Fig 2b - Dimensions - Solar models
579
694
A
B
D
C
678
E
F
KEY
A
B
C
D
E
F
G
G
OVERALL HEIGHT
HEAT PUMP FLOW CONNECTION
TUNSISH OUTLET CONNECTION
HEAT PUMP RETURN CONNECTION
HEATING CIRCUIT FLOW CONNECTION
HEATING CIRCUIT RETRUN CONNECTION
SOLAR COIL CONNECTIONS
CAPACITY
210
250
300
A
1497
1749
2064
B
1350
1350
1350
C
877
1129
1444
D
939
939
939
E
549
549
549
F
404
404
404
G
373
373
373
Solar coil specification:
Surface Area: 1.1m2
Coil volume: 5.8 litres
Pressure drop: 3.6 kPa (0.036 bar)
Output rating: 30kW at 80oC flow temperature, 15 litres/minute flow rate
Connections: 22mm compression / 3/4” BSP male
8
Fig 2c - Dimensions - Slimline models
Ø 491
595
A
B
C
600
D
E
F
KEY
A
B
C
D
E
F
OVERALL HEIGHT
HEAT PUMP FLOW CONNECTION
TUNSISH OUTLET CONNECTION
HEAT PUMP RETURN CONNECTION
HEATING CIRCUIT FLOW CONNECTION
HEATING CIRCUIT RETRUN CONNECTION
CAPACITY
150
170
A
1495
1669
B
1051
1051
C
944
1118
D
641
939
E
250
549
F
105
404
9
10
Control Board
(optionally powered
by outdoor unit)
Immersion heater
Vessel
Insulation
DHW circuit
Primary circuit
Mechanical zones
Optional wireles room thermostat and wireless receiver
Electrical data
Weight empty/full (kg)
Materials
Dimensions (mm)
Safety devices
UNIT
Nominal hot water capacity (litres)
Water
STANDARD
170
210
250
300
14.3 - 25.8 - 32.1 - 40.1 l/min
Primary flow rate W50-W85-W112-HW140
Primary - 2 x Grundfos UPS2 25-60, DHW Grundfos
Pump
UPSO 15-60 CIL2
22
Connection size Heating/DHA (mm)
DHW Expansion vessel (litres)
12
18
18
24
24
Charge pressure (MPa (bar))
0.35 (3.5)
Control thermistor (oC)
1-80
0.3 (3.0)
Pressue Relief Valve (MPa (bar))
o
40 - 70
Control thermistor ( C)
Over-temperature cut-out (oC)
80 +/- 5
Temp/Pressure Relief Valve (oC/MPa (bar))
90 / 1.0 (10.0)
Expansion valve (MPa (bar))
0.8 (8.0)
712
712
712
712
712
Width
Depth
691
691
691
691
691
1113
1239
1491
1743
2057
Height
56 / 206 62 / 232 69 / 279 77 / 327 87 / 387
Duplex stainless steel
Type
Expanded polyurethane (PU)
Nominal thickness (mm)
60
Standing heat loss (kWh/24h)
1.19
1.32
1.57
1.67
1.89
Ozone Depletion Potential
zero
Global Warming Potential
3.1
Electrical supply
220 - 240 V ~ , 50Hz
single
Phase
Fuse rating - MCB Size (A)
10
Electrical supply
220 - 240 V ~ , 50Hz
Phase
single
Rating (kW at 240V)
3
Max current (A)
13
Fuse rating - MCB Size (A)
16
DHW and 1 heating zone
PAR-WT50-E controller & PAR-WR51-E receiver
150
Table 2 - STANDARD Cylinder Technical Data
SOLAR
210
250
300
Primary flow rate W50-W85-W112-HW140
14.3 - 25.8 - 32.1 - 40.1 l/min
Pump
Primary - 2 x Grundfos UPS2 15-60, DHW Grundfos
UPSO 15-60 CIL2
Connection size Heating/DHA (mm)
22
DHW Expansion vessel (litres)
18
24
24
Charge pressure (MPa (bar))
0.35 (3.5)
Solar coil heating surface (m2)
1.1
o
Control thermistor ( C)
Safety devices
Primary circuit
1 - 80
0.3 (3.0)
Pressue Relief Valve (MPa (bar))
DHW circuit
40 - 70
Control thermistor (oC)
Over-temperature cut-out (oC)
80 +/- 5
Temp/Pressure Relief Valve (oC/MPa (bar))
90 / 1.0 (10.0)
Expansion valve (MPa (bar))
0.8 (8.0)
Width
Dimensions (mm)
678
678
678
694
694
694
Depth
1497
1749
2064
Height
74 / 284 82 / 332 92 / 392
Weight empty/full (kg)
Materials
Cylinder
Duplex stainless steel
Vessel
316L stainless steel
Solar heating coil
Insulation
Expanded polyurethane (PU)
Type
60
Nominal thickness (mm)
Standing heat loss (kWh/24h)
1.56
1.63
1.84
zero
Ozone Depletion Potential
3.1
Global Warming Potential
Electrical data
Control Board (optionally
powered
by outdoor unit
220 - 240 V ~ , 50Hz
Electrical
supply
single
Phase
10
Fuse rating - MCB Size (A)
Immersion heater
220 - 240 V ~ , 50Hz
Electrical supply
single
Phase
3
Rating (kW at 240V)
13
Max current (A)
16
Fuse rating - MCB Size (A)
Mechanical zones
DHW and 1 heating zone
Optional wireles room thermostat and wireless receiver
PAR-WT50-E controller & PAR-WR51-E receiver
UNIT
Nominal hot water capacity (litres)
Water
Table 3 - SOLAR Cylinder Technical Data
11
12
150
SLIMLINE
Duplex stainless steel
Expanded polyurethane (PU)
60
60 / 230
zero
3.1
220 - 240 V ~ , 50Hz
single
10
220 - 240 V ~ , 50Hz
single
3
13
16
DHW and 1 heating zone
PAR-WT50-E controller & PAR-WR51-E receiver
54 / 204
170
14.3 - 25.8 - 32.1 - 40.1 l/min
Primary - 2 x Grundfos UPS2 15-60, DHW Grundfos
UPSO 15-60 CIL2
22
Connection size Heating/DHA (mm)
DHW Expansion vessel (litres)
12
18
Charge pressure (MPa (bar))
0.35 (3.5)
Control thermistor (oC)
1 - 80
Pressue Relief Valve (MPa (bar))
0.3 (3.0)
Control thermistor (oC)
40 - 70
Over-temperature cut-out (oC)
80 +/- 5
Temp/Pressure Relief Valve (oC/MPa (bar))
90 / 1.0 (10.0)
Expansion valve (MPa (bar))
0.8 (8.0)
600
600
Width
595
595
Depth
1495
1669
Height
Primary flow rate W50-W85-W112-HW140
Pump
Type
Nominal thickness (mm)
Standing heat loss (kWh/24h)
Ozone Depletion Potential
Global Warming Potential
Electrical
supply
powered
by outdoor unit
Control Board (optionally
Phase
Fuse rating - MCB Size (A)
Electrical supply
Immersion heater
Phase
Rating (kW at 240V)
Max current (A)
Fuse rating - MCB Size (A)
Vessel
Insulation
DHW circuit
Primary circuit
Mechanical zones
Optional wireles room thermostat and wireless receiver
Electrical data
Weight empty/full (kg)
Materials
Dimensions (mm)
Safety devices
UNIT
Nominal hot water capacity (litres)
Water
Table 4 - SLIMLINE Cylinder Technical Data
Graph 1 - Primary Pump performance curves
13
INSTALLATION – GENERAL
PIPE FITTINGS
The connection points to the heating system are in 22mm copper pipe. The use of appropriately sized COMPRESSION
FITTINGS is recommended when connecting to the pipes. Solder fittings can be used, but extreme care must be taken to
ensure any anciallry components in close proximity are not damaged by heat. Push fit type fittings can be used for connection
to the copper pipes.
The inlet connection to the cold water combination valve is 22mm compression. The cylinder outlet fitting is suitable for
connection to 22mm o/dia pipe (compression nut and olive supplied). The outlet is also threaded 3/4” BSP male parallel
should threaded pipe connections be preferred.
COLD FEED
A 22mm cold water supply is recommended, however, if a 15mm (1/2”) supply exists which provides sufficient flow, this may
be used. More flow noise may be experienced from small bore pipes due to the increased water velocity through them.
A stopcock or servicing valve should be incorporated into the cold water supply to enable the cylinder and its associated
controls to be isolated and serviced.
PRESSURE REDUCING VALVE (Fig 3 below)
The 3.5 bar pressure reducing valve can be connected anywhere on the cold water mains supply prior to the Air Source
Heat Pump cylinder. There is no requirement to site it close to the unit, it can be located at a point where the mains supply
enters the premises if this is more convenient but you must install a non-return valve just after the reducing valve for ease
of maintenance.
Fig 3 - Pressure reducing valve
Fig 4 - Pressure relief valve (8 bar)
Pressure reducing valve
cartridge (3 bar)
Pressure relief valve
discharge connection
Take note of flow
direction
Take note of flow
direction
From cold water
combination
valve
Mains in
Outlet to cylinder
Outlet to cylinder
Pressure relief valve
“TEE” (incorporates
check valve)
22mm compression connection
22mm compression connection
PRESSURE RELIEF VALVE (Fig 4 above)
Should a balanced pressure cold water supply be required to cold water outlets such as thermostatic shower mixer valves or
combination taps, the cold water balanced draw off connection should be taken from between the pressure reducing valve
and the pressure relief valve (see Fig 4 above). Branches to cold drinking water outlets should be taken directly from the
mains supply.
EXPANSION VESSEL
The expansion vessel accommodates expansion that results from heating the water inside the unit. The expansion vessel
is pre-charged at 3.5 bar. The expansion vessel must be connected between the expansion valve (see Fig. 4 above) and
the cylinder by connecting it to the expansion vessel tapping on the cold feed pipe (see Fig 1 for position of tapping). The
location of the expansion vessel should allow access to recharge the pressure as and when necessary, this can be done
using a normal car foot pump. It is recommended that the expansion vessel is adequately supported. An expansion vessel
wall mounting bracket is supplied for this purpose and should be fitted.
TUNDISH
The tundish is supplied factory fitted . Ensure it is not postitioned directly over any electrical device in case any water splashes
occur in the event of a safety valve discharge.
14
DRAIN TAPS
Drain taps are fitted to both the primary system pipework and to the cold water inlet to facilitate draining the unit or indirect
heating circuit for maintenance purposes. It is recommended that the outlet point of the drain pipe work be at least 1 metre
below the level of the heater (this can be achieved by attaching a hose pipe to the drain tap outlet spigot).
HOT WATER OUTLET
Ideally the pipework from the cylinder to the outlet fittings should be in 22mm pipe with short runs of 15mm pipe to showers
and basin taps. Small bore pipe can also be used to suit some taps, but runs should be of minimum length. Pipe sizes may
vary due to system design.
SECONDARY CIRCULATION
If secondary circulation is required it is recommended that it be connected to the cylinder as shown in Fig 5 below via a swept
tee joint into the cold feed to the unit. NOTE: A SECONDARY CIRCULATION CONNECTION AT THIS POINT MUST NOT
BE USED ON SOLAR MODELS AS IT WILL DISTURB THE DEDICATED SOLAR VOLUME OF THE CYLINDER.
The secondary return pipe should be in 15mm pipe and incorporate a check valve to prevent backflow. A suitable WRAS
approved bronze circulation pump will be required. On large systems, due to the increase in system water content, it may be
necessary to fit an additional expansion vessel to the secondary circuit. This should be done if the capacity of the secondary
circuit exceeds 10 litres.
Fig 5 - Secondary circulation connection
Cold
Swept
Pipe capacity (copper):
supply
tee
15mm O.D. = 0.13 l/m (10 litres = 77m)
22mm O.D. = 0.38 l/m (10 litres = 26m)
28mm O.D. = 0.55 l/m (10 litres = 18m)
Secondary
return
Cold inlet
connection
Check
valve
WARNINGS
Secondary
circulation
pump
i) Under no circumstances should the factory fitted temperature/pressure relief valve be removed other than by authorised
service personnel. To do so will invalidate any guarantee or claim.
ii) The cold water combination valve must be fitted to the mains water supply to the unit.
iii) No control or safety valves should be tampered with.
iv) The discharge pipe should not be blocked or used for any other purpose.
Fig 6 - T&P Relief Valve insulation
B
A
T&P RELIEF
VALVE
DISCHARGE
PIPEWORK
LEFT HAND
INSULATING PIECE
RIGHT HAND
INSULATING PIECE
TUNDISH
D
C
PLASTIC COVER
DISCHARGE PIPE
CLIP INTO
PLACE !
15
16
16
19
17
20
15
Pa
25
27
21
12
26
13
4
2
3
HWS supply
10
24
7
Scale Trap
25
DHW Circulating Pump
26
Flow Sensor
27
Primary Pump
Primary Expansion Vessel
Primary Pressure Relief valve
Magnetic Filter
Primary System Pressure Gauge
3 Way Motorised Diverter Valve
Low Loss Header incorporating ports for
2nd heating zone and alternative heat source
Primary Pump
DHW Drainoff point
11
6
Balanced cold water
draw-off
Discharge pipe to atmosphere
(see page 12 “Installation - Discharge”)
14
22
23
KEY
1
Heat Pump
13
2
Cylinder
14
3
FTC5 Controller
15
4
Immersion heater
16
5
3.5 bar Pressure reducing Valve incorporating
17
Strainer and Check Valve (supplied loose)
18
6
8 bar Expansion Valve and Check Valve
19
7
DHW Expansion Vessel (supplied loose)
20
8
Stop Cock
21
9
Mains Stop Cock
22
10
Tundish
11
Temperature/Pressure relief Valve
23
12
Plate to PLate Heat Exchanger
24
1
18
To space heating
circuit Zone 1
Balanced HWS and
MCWS to bathrooms,
showers, cloakrooms,
etc
Incoming Cold
Water Main
MCWS to Kitchen
(unbalanced cold
mains supply)
Primary circuit draw off point
Automatic Air Vent
Differential Pressure Bypass Valve
(supplied loose
Parts shown within dashed
line are supplied
9
8
5
Fig 7 - Schematic installation diagram
INSTALLATION - DISCHARGE
It is a requirement of Building Regulation G3 that any discharge from an unvented system is conveyed to where it is visible,
but will not cause danger to persons in or about the building. The tundish and discharge pipes should be fitted in accordance
with the requirements and guidance notes of Building Regulation G3. The G3 Requirements and Guidance section 3.50 3.63 are reproduced in the following sections of this manual. For discharge pipe arrangements not covered by G3 Guidance
advice should be sought from your local Building Control Officer. Any discharge pipe connected to the pressure relief devices
(Expansion Valve and Temperature/Pressure Relief Valve) must be installed in a continuously downward direction and in a
frost free environment.
Water may drip from the discharge pipe of the pressure relief device. This pipe must be left open to the atmosphere. The
pressure relief device is to be operated regularly to remove lime deposits and to verify that it is not blocked.
G3 REQUIREMENT
“...there shall be precautions...to ensure that the hot water discharged from safety devices is safely conveyed to where it is
visible but will not cause danger to persons in or about the building.”
Notes:
Discharge pipe-work D2 can now be a plastic pipe but only pipes that have been tested to a minimum 110°C must be used.
Discharge pipe D2 can now be plumbed into the soil stack but only soil stacks that can handle temperatures of 99°C or
greater should be used.
The following extract is taken from the latest G3 Regulations
Discharge pipe D1
3.50 Safety devices such as temperature relief valves or combined temperature and pressure and pressure relief valves
(see paragraphs 3.13 or 3.18) should discharge either directly or by way of a manifold via a short length of metal pipe (D1)
to a tundish.
3.51 The diameter of discharge pipe (D1) should be not less than the nominal outlet size of the temperature relief valve.
3.52 Where a manifold is used it should be sized to accept and discharge the total discharge form the discharge pipes
connected to it.
3.53 Where valves other than the temperature and pressure relief valve from a single unvented hot water system discharge
by way of the same manifold that is used by the safety devices, the manifold should be factory fitted as part of the hot water
storage system unit or package.
Tundish
3.54 The tundish should be vertical, located in the same space as the unvented hot water storage system and be fitted as
close as possible to, and lower than, the valve, with no more than 600mm of pipe between the valve outlet and the tundish
(Fig. 8 & Table 5, page 19).
Note: To comply with the Water Supply (Water Fittings) Regulations, the tundish should incorporate a suitable air gap.
3.55 Any discharge should be visible at the tundish. In addition, where discharges from safety devices may not be apparent,
e.g. in dwellings occupied by people with impaired vision or mobility, consideration should be given to the installation of a
suitable safety device to warn when discharge takes place, e.g. electronically operated.
Discharge pipe D2
3.56 The discharge pipe (D2) from the tundish should:
(a) have a vertical section of pipe at least 300mm long below the tundish before any elbows or bends in the pipework (see
Diagram 1, G3), (Fig. 8, page 19); and
(b) be installed with a continuous fall thereafter of at least 1 in 200.
3.57 The discharge pipe (D2) should be made of:
(a) metal; or
(b) other material that has been demonstrated to be capable of safely withstanding temperatures of the water discharged
and is clearly and permanently marked to identify the product and performance standard (e.g. as specified in the relevant
part of BS 7291).
3.58 The discharge pipe (D2) should 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. for discharge pipes between 9m
and 18m the 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 flow resistance.
(See Diagram 1, Table 1, G3), (Fig. 8 & Table 5, page 19) and the worked example.
17
Note: An alternative approach for sizing discharge pipes would be to follow Annex D, section D.2 of BS 6700:2006 Specification
for design, installation, testing and maintenance of services supplying water for domestic use within buildings and their
curtilages.
3.59 Where a single common discharge pipe serves more than one system, it should be at least one pipe size larger than
the largest individual discharge pipe(D2) to be connected.
3.60 The discharge pipe should not be connected to a soil discharge stack unless it can be demonstrated that that the soil
discharge stack is capable of safely withstanding temperatures of the water discharged, in which case, it should:
(a) contain a mechanical seal, not incorporating a water trap, which allows water into the branch pipe without allowing foul
air from the drain to be ventilated through the tundish;
(b) be a separate branch pipe with no sanitary appliances connected to it;
(c)
if plastic pipes are used as branch pipes carrying discharge from a safety device they should be either polybutalene
(PB) to Class S of BS 7291-2:2006 or cross linked polyethylene (PE-X) to Class S of BS 7291-3:2006; and
(d) be continuously marked with a warning that no sanitary appliances should be connected to the pipe.
Note:
1. Plastic pipes should be joined and assembled with fittings appropriate to the circumstances in which they are used as set
out in BS EN ISO 1043-1.
2. Where pipes cannot be connected to the stack it may be possible to route a dedicated pipe alongside or in close proximity
to the discharge stack.
Termination of discharge pipe
3.61 The discharge pipe (D2) from the tundish should terminate in a safe place where there is no risk to persons in the
vicinity of the discharge.
3.62 Examples of acceptable discharge arrangements are:
(b) to a trapped gully with the end of the pipe below a fixed grating and above the water seal;
(c) downward discharges at 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; and
(d) discharges at high level: e.g. into a metal hopper and metal downpipe 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 system that
would collect such discharges.
3.63 The discharge would consist of high temperature water and steam. Asphalt, roofing felt and non-metallic rainwater
goods may be damaged by such discharges.
Worked example of discharge pipe sizing
Fig. 7, page 19: shows a G1/2 temperature relief valve with a discharge pipe (D2) having 4 No. elbows and length of 7m from
the tundish to the point of discharge.
From Table 5, page 19:
Maximum resistance allowed for a straight length of 22mm copper discharge pipe (D2) from a G1/2
temperature relief valve is 9.0m.
Subtract the resistance for 4 No. 22mm elbows at 0.8m each = 3.2m
Therefore the permitted length equates to: 5.8m
5.8m is less than the actual length of 7m therefore calculate the next largest size.
Maximum resistance allowed for a straight length of 28mm pipe (D2) from a G1/2 temperature relief valves equates to 18m.
Subtract the resistance of 4 No. 28mm elbows at 1.0m each = 4.0m
Therefore the maximum permitted length equates to: 14m
As the actual length is 7m, a 28mm (D2) copper pipe will be satisfactory.
WARNINGS:
• Under no circumstances should the factory fitted temperature/pressure relief valve be removed other than by a competent
person. To do so will invalidate any guarantee or claim.
• The cold water combination valve assembly must be fitted on the water supply to the Pre-plumbed cylinder.
• No control or safety valves should be tampered with or used for any other purpose.
• The discharge pipe should not be blocked or used for any other purpose.
• The tundish should not be located adjacent to any electrical components.
18
Table 5 - Sizing of copper discharge pipe (D2) for common temperature relief valve outlet sizes
VALVE OUTLET SIZE
MINIMUM SIZE OF
DISCHARGE PIPE
D1
MINIMUM SIZE OF
DISCHARGE PIPE
D2 FROM TUNDISH
MAXIMUM
RESISTANCE
ALLOWED,
EXPRESSED AS
A LENGTH OF
STRAIGHT PIPE (i.e.
NO ELBOWS OR
BENDS)
G 1/2
15mm
22mm
28mm
35mm
UP TO 9m
UP TO 18m
UP TO 27m
0.8m
1.0m
1.4m
G 3/4
22mm
28mm
35mm
42mm
UP TO 9m
UP TO 18m
UP TO 27m
1.0m
1.4m
1.7m
G1
28mm
35mm
42mm
54mm
UP TO 9m
UP TO 18m
UP TO 27m
1.4m
1.7m
2.3m
RESISTANCE
CREATED BY EACH
ELBOW OR BEND
NOTE: The above table is based on copper tube. Plastic pipes may be of different bore and resistance. Sizes and maximum
lengths of plastic should be calculated using data prepared for the type of pipe being used.
Fig. 8: Typical discharge pipe arrangement (extract from Building Regulation G3 Guidance section 3.5)
Safety device
(e.g. Temperature
relief valve)
Metal discharge pipe (D1) from
Temperature relief valve to tundish
Tundish
600mm maximum
300mm
minimum
Discharge below
fixed grating
(Building Regulation
G3 section 3.61 gives
alternative points
of discharge)
Fixed grating
Discharge pipe (D2 from tundish,
with continuous fall. See Building
Regulation G3 section 3.56,
Table 4 and worked example)
Trapped
gully
19
INSTALLATION - HEAT PUMP PRIMARY CIRCUIT
HEAT PUMP SELECTION
• The Pre-plumbed cylinders are suitable for use with the Mitsubishi Electric Ecodan Air Source heat pumps listed in Table
6 below
• If in doubt consult Mitsubishi Electric for further advice.
• Solid fuel boilers or any other boiler in which the energy input is not under effective thermostatic control unless additional
and appropriate safety measures are installed should NOT be used.
• The primary circuit can either be a sealed system or open vented type, maximum primary circuit pressure 3 bar.
• The primary flow from the heat pump MUST be pumped. Gravity circulation will not work due to the special design of the
primary heat exchanger.
• The heat pump cannot be vented through the Pre-plumbed cylinder unit.
Table 6
Cylinder/HP Matrix
Heat pump output kW
150Std
170Std
5
X
X
8.5
X
X
X
X
X
X
X
X
X
X
11.2
14
210Std
250Std
300Std
150Slim 170Slim 210Solar 250Solar 300Solar
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
WATER QUALITY AND SYSTEM PREPARATION
General
The water in both primary and DHW circuits should be clean and with a pH value of 6.5 to 8.0
The following values should not be exceeded in the water supply conditions:
Calcium: 100mg/L
Ca hardness: 250mg/L
Chlorine: 100mg/L
Chloride: 250mg/L
Copper: 0.3mg/L
Iron/Manganese: 0.5mg/L
Other constituents should comply with European Directive 98/83 EC
In known hard water areas, to minimise any scaling the stored DHW temperature should be restricted to 60oC
Anti-freeze
Anti-freeze solutions MUST use propylene glycol with a toxicity rating of Class 1 as listed in the Clinical Toxicology of
Commercial Products, 5th Edition
Note:
1. Ethylene glycol is toxic and MUST NOT be used in the primary water ciruit in case of any cross contamination of the
potable water circuit
2. For 2 zone valve ON/OFF control, propylene glycol MUST be used
New and Existing Installations (primary water circuit)
Before connecting the outdoor unit, thoroughly cleanse the primary pipework of building debris, solder, fluxes, etc. using a
suitable chemical cleansing agent.
Flush the system to remove the chemical cleanser
For all packaged model systems add a combined inhibitor and anti-freeze solution to prevent damage to the pipework and
system components.
For split model systems the responsible installer should decide if anti-freeze solution is necessary for each site’s conditions.
Corrosion inhibitor however should always be used.
When using chemical cleansers and inhibitors always follow the manufacturer’s instructions and ensure the product is
appropriate for the materials used in the water circuit.
Minimum amount of water required in the space heating circuit and required flow rates
Outdoor heat pump unit
Min water content
Required flow rate PUHZ-W50
40 litres
14.3 L/min
PUHZ-W85
60 litres
25.8 L/min
PUHZ-W112
80 litres
32.1 L/min
PUHZ-HW140
100 litres
40.1 L/min
20
MAIN CONTROLLER FLOW RATE LOOK UP
The main controller can now show you the flow rates by using Request Code 540 in the Service Menu.
WIRING
All electrical wiring should be carried out by a competent electrician and be in accordance with the latest I.E.E. Wiring
Regulations.
The Pre-plumbed cylinder thermal controls, primary circulating pumps are factory pre-wired. Further wiring will be required
between the FTC5 controller, the programmer, room temperature sensor and the Heat Pump. Additional controls and wiring
will be required if a second CH zone is to be fitted to the instalation.
Any thermal controls and over-temperature thermal cut-outs MUST NOT be bypassed.
The mains supply must be via a double pole isolating switch with a contact separation of at least 3mm in both poles. The
supply must be fused 10 amp. A supply cable of 1.0 to 1.5mm2 cross sectional area should be used.
THIS APPLIANCE MUST BE EARTHED
HEATING SYSTEM CONTROLS
The controls provided with the Air Source Heat Pump pre-plumbed cylinder will ensure the safe operation of the unit within
a central heating system.
Connection to the various system components is made via the FTC5 Controller fitted to the front of the Pre-plumbed cylinder,
refer to the Manual supplied for the FTC5 Controller and the terminal identification labels within the FTC5 Controller to aid
in connecting the various external system components such as the mains supply, programmer and heat pump. The wiring
to the external components is made using flexible cable, this should be secured using the integral cable grips located in the
FTC5 Controller.
Fig 9 - Optional 2 zone control pack - plumbing schematic
Fig 10 - 2 zone control pack - component wiring
Primary Flow
Secondary Z1 Flow
TBO.1 5-6 (OUT3)
Secondary Z2 Flow
TBO.4 1-2 (OUT13)
Secondary Z2 Return
Primary Return
Secondary Z1 Return
TBO.1 1-2 (OUT1)
21
Fig 11 - 2 zone control pack - temperature sensor wiring
Primary Flow
Secondary Z1 Flow
Secondary Z2 Flow
TB1.2 3-4 (THW6)
TB1.2 7-8 (THW8)
TB1.2 9-10 (THW9)
Secondary Z2 Return
Primary Return
Secondary Z1 Return
TB1.2 5-6 (THW7)
Fig 12 - 2 zone control pack - dip switch settings
SW2-7 - ON
SW3-6 - ON
22
Fig 13 - Optional 2 zone twin temperature control pack - plumbing schematic
Fig 14 - Optional 2 zone twin temperature control pack - component wiring
Secondary Z1 Flow
Mixing Valve
TBO.1 3-4 (OUT2)
Secondary Z2 Flow
TBO.1 5-6 (OUT3)
TBO.2 1-2-3 (OUT5)
Secondary Z2 Return
Secondary Z1 Return
23
Fig 15 - Optional 2 zone twin temperature control pack - sensor wiring
TB1.2 3-4 (THW6)
Secondary Z1 Flow
Mixing Valve
Secondary Z2 Flow
TB1.2 7-8 (THW8)
Secondary Z2 Return
Secondary Z1 Return
TB1.2 9-10 (THW9)
TB1.2 5-6 (THW7)
Fig 16 - Optional 2 zone twin temperature control pack - dip switch settings
SW2-7 - ON
24
Fig 17 - Wiring of Motorised Mixing valve
TO RIGHT HAND
PRIMARY PUMP
TO LEFT HAND
PRIMARY PUMP
(CABLE WITH
WHITE ID TAG)
Fig 18 - Schematic of Motorised Mixing Valve hydraulic connections
BLUE
DHW PUMP
CONNECTION TO
PCB BY MEANS OF
RED JST PLUG
CONNECTOR TO
SOCKET CNP1
BROWN
BLUE
BROWN
BLUE
TO 3 WAY VALVE
ACTUATOR HEAD
ALL EARTH CONDUCTOR CONNECTIONS
TO BE MADE TO EARTHING SCREWS ON
FTC-5 CONTROLLER REAR CHASSIS
BLACK
BROWN
TO DHW
CIRCULATING PUMP
FLOW AND RETURN
SENSORS
CONNECTION TO
PCB BY MEANS OF
RED JST PLUG
CONNECTOR TO
TANK SENSOR
CONNECTION TO
PCB BY MEANS OF
WHITE JST PLUG
CONNECTOR TO
SOCKET CNW5
Fig 19 - Factory made conections to FTC5
controller PCB
TO RETURN SENSOR
(SENSOR TO BE
INSERTED IN
POCKET ON
RETURN PIPE)
BLACK SLEEVING
WHITE
TO FLOW SENSOR
ASSEMBLY
BROWN
GREEN
TO TANK SENSOR
(SENSOR TO BE
INSERTED IN SPARE
POCKET ON
ELEMENT PLATE)
TO FLOW SENSOR
(SENSOR TO BE
INSERTED IN
POCKET ON FLOW
PIPE) GREY
SLEEVING
25
26
27
28
SOLAR PRIMARY
CONNECTION TO THE SOLAR PRIMARY CIRCUIT
The lower coil of the Solar models must be connected to a fully pumped solar primary circuit. The connections are suitable
for a 22mm copper pipe direct to compression fittings provided. The connections are also threaded 3/4” BSP male parallel
should BSP connections be required.
The solar primary circuit must have its own dedicated circulating pump, thermal and safety controls which must be installed
as per the manufacturer’s instructions.
CONTROL OF SOLAR PRIMARY CIRCUIT
Temperature control of the Solar models when heated by a solar thermal system must be carried out using a suitable proprietary solar differential temperature controller. The cylinder temperature sensing probe (usually supplied with the solar
differential temperature controller) should be inserted into the pocket provided on the cylinder and its cable secured using
the cable clamp supplied.
The solar controller and solar primary circulation pump must be wired via the over-temperature cut-out mounted in the lower
solar controls housing (see Fig 20). This will ensure that the heat input to the solar coil is interrupted in the event of the
cylinder over-heating. There must also be suitable Check (non-return) valves installed in the solar primary flow and return to
prevent the possibility of any thermo-syphoning if the solar circulation is stopped.
Connection to the solar differential temperature controller should be in accordance with the manufacturer’s instructions. The
controller should be set to give a recommended cylinder temperature of approx. 60°C otherwise nuisance operation of the
thermal cut-outs may occur.
Fig 20 - Solar thermal cut-out wiring
SOLAR CUT-OUT
(LOWER) TERMINAL
HOUSING
SOLAR
THERMAL
CUT-OUT
SOLAR
CONTROLLER
POWER SUPPLY TO
SOLAR CONTROLLER
L
N
29
IMMERSION HEATER
The pre-plumbed cylinder units are supplied fitted with an immersion heater which can be used to supplement the Air Source
Heat Pump heating input. The immersion heater is located within the controls housing. Refer to Fig 21 below for details of wiring
of the immersion heater. The mains supply circuit to the immersion heater must be protected by a suitable fuse and
double pole isolating switch with a contact separation of at least 3mm in both poles. THE IMMERSION HEATER MUST
BE EARTHED.The supply cable for the immersion heater must be aminimum of 1.5mm2 3 core HOFR sheathed.
DO NOT BYPASS THE THERMAL CUT-OUT IN ANY CIRCUMSTANCES
Fig 21 - Immersion heater wiring
EARTH SCREW ON FTC-5
CONTROLLER BACKPLATE
GREEN / YELLOW
BROWN
FTC5 CONTROLLER
BLUE
ECB
1
3
2
4
RED
TO PLUG REFERENCE
CNIH ORN ON FTC-5
PCB
IMMERSION HEATER
MAINS SUPPLY CABLE
1.5mm2 3 CORE HOFR
CABLE
BLUE
ORANGE
ORANGE
IHC
1/L1 3/L2 5/L3
A1
2/T1 4/T2 6/T3
A2
BROWN
BLUE
GREEN / YELLOW
IMMERSION
HEATER TERMINAL
HOUSING
B
THERMAL
CUT-OUT
A
EARTH
CONNECTION
30
COMMISSIONING
At the time of commissioning, please ensure a Commissioning Checklist is completed for the installation.
FILLING THE UNIT WITH WATER
•
•
•
•
•
•
•
BEFORE FILLING CHECK AND TIGHTEN ALL MECHANICAL JOINTS AND CONNECTIONS IN CASE THESE HAVE
LOOSENED DURING TRANSIT.
Check expansion vessel pre-charge pressure. The vessel is supplied precharged to 3.5 bar to match the control pressure
of the pressure reducing valve. The precharge pressure is checked using a car tyre gauge by unscrewing the plastic
cap opposite the water connection.
Check all connections for tightness including the immersion heater(s). An immersion heater key spanner is supplied for
this purpose.
Ensure the drain cock is CLOSED.
Open a hot tap furthest from the cylinder.
Open the cylinder isolating valve to fill the unit. When water flows from the tap, allow to run for a few minutes to thoroughly
flush through any residue, dirt or swarf, then close the tap.
Open successive hot taps to purge the system of air.
SYSTEM CHECKS
•
•
•
•
•
Check all water connections for leaks and rectify as necessary.
Turn off water supply to the cylinder.
Remove the pressure reducing valve head work to access the strainer mesh, clean and re-fit.
Manually open, for a few seconds, each relief valve in turn, checking that water is discharged and runs freely through
the tundish and out at the discharge point.
Ensure that the valve(s) reseat satisfactorily.
DOMESTIC HOT WATER (DHW) CIRCULATION
Ensure the DHW circulation pump is set to speed setting II to ensure optimum DHW heating performance. Failure to
do so can result in excessive use of the back-up immersion heater or lower storage temperatures than required.
PRIMARY CIRCUIT
Fill the primary circuit following the Air Source Heat Pump commissioning instructions. Vent any trapped air. Check the primary
system for leaks and rectify as necessary. Flush the primary system in accordance with the instructions on Page 20 and add
a suitable inhibitor and anti-freeze solution when re-filling.
Switch on the electrical supply to the Air Source Heat Pump and immersion heater. Programme the Air Source Heat Pump
controller as detailed in the fitting and user instructions supplied with the controller. Set the controller for hot water operation
only. After a short delay the primary pump on the return to the Heat Pump and the DHW pump should run and the Heat Pump
operate. The temperature of the primary flow to the cylinder should increase, if it does not, check for a wiring or piping error.
Allow the unit to heat up.
Select the heating only function on the controller. Both primary pumps should run and the Heat Pump operates. The primary
flow to the cylinder primary pipework manifold and the radiator circuit should become hot, if it does not check for a wiring or
piping error.
The minimum hot water setting is 40 °C. The maximum hot water setting is 60 °C. In hard water areas a maximum of 60 oC
is recommended.
When the heating and hot water temperatures are reached, the pumps should stop running and the Heat Pump stop operating.
Check that no water is discharged from either the expansion valve or temperature and pressure relief valve during the
heating cycle. If the user temperatures or “On” and “Off” times have been adjusted for commissioning purposes, the controller
should be reset to the desired settings. The operation of the controller should be demonstrated to the user and the controller
installation and user instructions left with them for future reference.
AUTOMATIC SYSTEM BY-PASS
An automatic differential bypass valve is supplied loose with the cylinder. This should be installed between the primary flow
and the primary return to the main space heating zone from the Low Loss Header such that a minimum flow rate can be
maintained through the Heat Pump in the event of the heating circuit being satisfied. See Graph 2 on page 32 for setting
details for the valve
31
Graph 2 - Bypass valve pressure vs volume
32
MAINTENANCE
MAINTENANCE REQUIREMENTS
Unvented hot water systems have a continuing maintenance requirement in order to ensure safe working and optimum
performance. It is essential that the relief valve(s) are periodically inspected and manually opened to ensure no blockage
has occurred in the valves or discharge pipework. Similarly cleaning of the strainer element and replacement of the air in the
expansion vessel will help to prevent possible operational faults.
The maintenance checks described below should be performed by a competent person on a regular basis, e.g. annually to
coincide with Heat Pump maintenance.
After any maintenance, please complete the relevant service interval record documentation for the installation.
INSPECTION
The immersion heater boss can be used as an access for inspecting the cylinder internally.
SAFETY VALVE OPERATION
Manually operate the temperature/pressure relief valve for a few seconds. Check water is discharged and that it flows freely
through the tundish and discharge pipework. Check valve reseats correctly when released. NOTE: Water discharged may
be very hot!
Repeat the above procedure for the expansion relief valve.
STRAINER
Turn off the cold water supply, Heat Pump and immersion heater. The lowest hot water tap should then be opened to depressurise
the system. Remove the pressure reducing cartridge to access the strainer mesh. Wash any particulate matter from the
strainer under clean water. Re-assemble ensuring the seal is correctly fitted. DO NOT use any other type of sealant.
DESCALING IMMERSION HEATER(S)
Before removing the immersion heater, the unit must be drained. Ensure the water, electrical supply and Heat Pump are OFF
before draining. Attach a hosepipe to the drain cock having sufficient length to take water to a suitable discharge point below
the level of the unit. Open a hot tap close to the unit and open the drain cock to drain the unit.
IMMERSION HEATER REMOVAL
Open the cover to the immersion heater housing and disconnect wiring from immersion heater over-temperature cut-out.
Remove the over-temperature cutout by pulling from the terminal connections on the immersion heater. Unscrew immersion
heater backnut and remove immersion heater from the unit. A key spanner is supplied with the cylinder unit for easy removal/
tightening of the backnut(s). Over time, the immersion heater gasket may become stuck to the mating surface. To break
the seal, insert a round bladed screwdriver into one of the pockets on the immersion heater and gently lever up and down.
Carefully remove any scale from the surface of the element. DO NOT use a sharp implement as damage to the element
surface could be caused. Ensure sealing surfaces are clean and seals are undamaged, if in doubt fit a new gasket.
Replace immersion heater ensuring the (right angled) element hangs vertically downwards towards the base of the unit. It
may be helpful to support the immersion heater using a round bladed screwdriver inserted into one of the thermal control
pockets whilst the backnut is tightened. Replace over-temperature cutout rod into pocket. Replace the immersion heater
over-temperature cutout by carefully plugging the two male spade terminations on the underside of the thermostat head into
the corresponding terminations on the element. Rewire, check, close and secure immersion heater housing cover.
EXPANSION VESSEL CHARGE PRESSURE
Remove the dust cap on top of the vessel. Check the charge pressure using a tyre pressure gauge. The pressure (with system
de-pressurised) should be 0.35MPa (3.5 bar). If it is lower than the required setting it should be re-charged using a tyre pump
(Schrader valve type). DO NOT OVER-CHARGE. Re-check the pressure and when correct replace the dust cap.
RE-COMMISSIONING
Check all electrical and plumbing connections are secure. Close the drain cock. With a hot tap open, turn on the cold water
supply and allow unit to refill. DO NOT switch on the immersion heater or Heat Pump until the unit is full. When water flows
from the hot tap, allow to flow for a short while to purge air and flush through any disturbed particles. Close hot tap and then
open successive hot taps in the system to purge any air. When completely full and purged, check system for leaks. The
heating source (immersion heater and Heat Pump) can then be switched on.
33
CLEANING THE FERNOX TF-1 COMPACT MAGNETIC FILTER
Note: There is no need to remove the cap of the TF-1 filter for cleaning
Close the isolating valves either side of the TF-1 magnetic filter. Remove the magnetic core by pulling upwards. Wait 30 seconds
for any collected particles to settle in the filter body. Open the lower isolating valve then open the drain valve, collect any fluid
and debris in a suitable container. Close the drain valve and open the upper isolating valve. Vent any trapped air from the
filter by opening the air bleed screw on the cap. If necessary, re-pressurise the system using the filling loop fitted to the unit.
Should the cap need to be removed a spanner is provided in the accessory kit for this purpose. When replacing the cap a
new ‘o’ ring should be used, this is also provided in the kit. Air can be vented by opening the bleed screw in the centre of the
air vent valve, the complete valve does not need to be removed. Should the valve be removed a replacement ‘o’ ring should
be used (provided in accessory kit) when re-assembling.
SERVICE LOG BOOK
On completion of any maintenance or service of the pre-plumbed cylinder, the Service Log Book should be filled in to record
the actions taken and the date the work was undertaken.
Fig 22 - Fernox TF-1 Compact Magnetic Filter assembly
CAUTION: CONTAINS STRONG MAGNETIC FIELDS
IF YOU HAVE AN IMPLANTED CARDIAC DEVICE EXTRA
CAUTION SHOULD BE TAKEN WHEN HANDLING THE
TF-1 COMPACT FILTER AND MAGNETIC CORE
AIR VENT
MAGNET
ISOLATING VALVES
( 2 OFF )
INLET / OUTLET PORT
FILTER BODY CAP
FILTER BODY
DRAIN VALVE (DO NOT
REMOVE)
CAP AND KEY
34
ISOLATING VALVE
SEALING WASHERS
( 2 OFF )
FAULT FINDING & SERVICING
IMPORTANT
• After servicing, complete the relevant Service Interval Record for the installation.
• Servicing should only be carried out by competent persons in the installation and maintenance of unvented water heating
systems.
• Any spare parts used MUST be authorised Mitsubishi Electric parts.
• Disconnect the electrical supply before removing any electrical equipment covers.
• NEVER bypass any thermal controls or operate system without the necessary safety valves.
• Water contained in the Air Source Heat Pump pre-plumbed cylinder may be very hot, especially following a thermal control
failure. Caution must be taken when drawing water from the unit.
Table 4 - Fault Finding Table
FAULT
No hot water flow
Water from hot taps
is cold
Water discharges from
Expansion Valve
Water discharges from
T&P Relief Valve
Milky water
POSSIBLE CAUSE
REMEDY
1. Mains supply off.
2. Check and open stock cock.
2. Strainer blocked.
2. Turn off water supply. Remove strainer and clean (see
maintanance section).
3. Cold water combination valve incorrectly fitted.
3. Check and refit as required.
1. BACK UP immersion heater not switched on.
1. Check and switch on.
2. BACK UP immersion heater thermal cut-out
has operated.
2. Check. Reset by pushing button.
3. Programmer set to Central Heating only.
3. Check. Set to Domestic Hot Water programme.
4. Air Source Heat Pump not working.
4. Check heat pump operation. If fault is suspected, consult
heat pump instructions.
5. Thermal cut-out has operated.
5. Check. Reset by pushing button on cut-out. Check
operation of DHW thermal sensor
6. DHW circulating pump not connected
correctly.
6. Check wiring and/or plumbing connections to DHW
circulating pump. Check isolating valves are open
1. INTERMITTENTLY
Expansion vessel charge pressure has reduced
below 3.5bar.
1. See Maintance section for re-charging procedure.
2. CONTINUALLY
a. Cold water combination valve pressure
reducer not working correctly.
b. Expansion valve seat damaged.
2a. Check pressure from cold water combination valve. If
greater than 3.6 bar, replace pressure reducer cartridge.
2b. Remove expansion valve cartridge. Check condition of
seat. If necessary, fit new expansion valve cartridge.
1. Thermal control failure. NOTE water will be
very hot.
1. Switch off power to immersion heater(s) and /or shut down
Heat Pump. DO NOT turn off water supply. When discharge
stops check all thermal controls, replace if faulty.
1. Oxygenated water.
1. Water from a pressurised system releases oxygen
bubbles when flowing. The milkiness will disappear after
a short while.
SPARE PARTS
A full range of spare parts are available for the Mitsubishi Air Source Heat Pump pre-plumbed cylinder range (see Table 7,
page 36). Refer to the technical data label on the unit to identify the model installed and ensure the correct part is ordered.
You will need to quote the serial number which is printed on the data label.
FAULT FINDING
The fault finding chart (above) will enable operational faults to be identified and their possible causes rectified. Any work carried
out on this unvented water heater and its associated controls MUST be carried out by a competent installer for unvented
water heating systems. In case of doubt contact Service Support (see contact details on back page).
WARNING
DO NOT TAMPER WITH ANY OF THE SAFETY VALVES OR CONTROLS SUPPLIED WITH THE PRE-PLUMBED CYLINDER
AS THIS WILL INVALIDATE ANY GUARANTEE.
35
Table 7 - Spares list
36
DESCRIPTION
PART NO.
1
Immersion heater (including terminal shroud and gasket)
95602002
2
Immersion heater gasket
95611026
3
Immersion heater backnut
95605204
4
Immersion heater key spanner
95605205
5
Tundish
95607881
6
Expansion Valve (6 bar)
95605206
7
Expansion valve core housing (incorporating check valve)
95605207
8
Temperature / pressure relief valve
95605209
9
DHW Expansion vessel 12 litre ( 150 litre models)
95970022
10
DHW Expansion vessel 18 litre ( 170 and 210 litre models)
95970023
11
DHW Expansion vessel 24 litre (250 and 300 litre models)
95970024
12
Pressure Reducing Valve (3.5 bar)
95605211
13
Nut and olive pack (4 of each)
95970026
14
TSRU immersion heater over-temperature cutout
95602003
15
Differential bypass valve
95605208
16
Primary circulating pump
95970027
17
DHW circulating pump
54HSHDHW
18
Filling loop
95970029
19
Automatic air vent
95970032
20
Primary system pressure gauge
95970033
21
Drain valve
95605210
22
Terminal shroud
95970034
23
Flow sensor assembly
54HSHFS-SEN
24
Plate to plate heat exchanger
54HSHPHEX
25
Plate to plate heat exchanger insulation set
95970037
26
Terminal box cover (Standard and Solar models)
95970038
27
Terminal box cover (Slimline models)
95970039
28
Fernox TF1 magnetic filter
95970061
29
Primary pump isolating valve
95605212
30
DHW pump isolating valve
95605213
31
Scale trap assembly
95970062
32
3 way motorised diverter valve - Actuator head
54HSH3WV-ACT
33
3 way motorised diverter valve - Valve body
54HSH3WV-VLV
34
Flow temperture sensor assembly
PAC-TH011-E
35
Return temperature sensor assembly
PAC-TH011-E
36
DHW tank thermal sensor assembly
PAC-TH011TK-E
37
Solar sensor pocket assembly including gasket (Solar models only)
95970025
38
Solar thermal over-temperature cutout (Solar models only)
95970060
Fig 23 - Spares Diagram
28
7
20
6
19
8
32
33
5
29
17
16
30
23
24
25
31
21
26
Fig 24 - Pressure Reducing valve 3.5 bar
27
Fig 25 - Element spares
26 27
14
3
22
1
2
Cold Mains
Connection (22mm)
Outlet Connection
(22mm)
37
USER INSTRUCTIONS
WARNINGS
IF WATER ISSUES FROM THE TEMPERATURE/PRESSURE RELIEF VALVE ON THE PRE-PLUMBED CYLINDER,
SHUT DOWN THE HEAT PUMP AND IMMERSION HEATER. DO NOT TURN OFF ANY WATER SUPPLY. CONTACT A
COMPETENT INSTALLER FOR UNVENTED WATER HEATERS TO CHECK THE SYSTEM.
DO NOT TAMPER WITH ANY OF THE SAFETY VALVES FITTED TO THE PRE-PLUMBED CYLINDER. IF A FAULT IS
SUSPECTED, CONTACT A COMPETENT INSTALLER.
COMMISSIONING RECORD
Please ensure that the installer has fully completed a Commissioning Checklist and Record for the installation and that you
have signed it to say that you have received a full and clear explanation of its operation. The installer is legally required to
complete a commissioning checklist as a means of complying with the appropriate Building Regulations (England and Wales).
All installations must be notified to Local Area Building Control either directly or through a Competent Persons Scheme. A
Building Regulations Compliance Certificate will then be issued to the customer who should, on receipt, write the Notification
Number on the Commissioning Checklist.
This product should be serviced regularly to optimise its safety, efficiency and performance. The service engineer should
complete the relevant Service Record document after each service.
TEMPERATURE CONTROLS IMMERSION HEATER
The hot water storage temperature is set on the Programmer, the water temperature is sensed by means of a thermistor sensor
located in a pocket on the immersion heater assembly. This should be set to give a water storage temperature of approx. 55°
to 60°C. The immersion heater assembly is also fitted with an over-temperature cut-out. Access to the temperature sensor
and over-temperature cut-out can be made by opening the immersion heater cover - DISCONNECT THE ELECTRICAL
SUPPLY BEFORE OPENING THE COVER.
DO NOT bypass the thermal cut-out(s) in any circumstances.
HEATING BY HEAT PUMP The space heating control temperature and the operating times for heating and hot water are set using the remotely mounted
controller. The optimum temperatures and times will have been set during commissioning. Should the temperatures or timings
need to be altered, refer to the installation and user instructions leaflet supplied with the controller for the method of adjustment.
FLOW PERFORMANCE
When initially opening hot outlets a small surge in flow may be noticed as pressures stabilise. This is quite normal with
unvented systems. In some areas cloudiness may be noticed in the hot water. This is due to aeration of the water is quite
normal and will quickly clear.
OPERATIONAL FAULTS
Operational faults and their possible causes are detailed in the Fault Finding section (page 35) of this manual. It is recommended
that faults should be checked by a competent installer.
The air volume within the expansion vessel will periodically require recharging to ensure expanded water is accommodated
within the unit. A discharge of water INTERMITTENTLY from the expansion valve will indicate the air volume has reduced to
a point where it can no longer accommodate the expansion.
38
39
ENVIRONMENTAL
Products are manufactured from many recyclable materials. At the end of their useful life they should be disposed of at a
Local Authority Recycling Centre in order to realise the full environmental benefits.
Insulation is by means of an approved CFC/HCFC free polyurethane foam with an ozone depletion factor of zero.
Telephone: 01707 282880
After Sales Service: 0161 866 6089
Email: heating@meuk.mee.com
Web: heating.mitsubishielectric.co.uk
UNITED KINGDOM
Mitsubishi Electric Europe
Living Environmental Systems Division
Travellers Lane
Hatfield
Hertfordshire
AL10 8XB
General Enquiries
Telephone: 01707 282880
Fax: 01707 278881
IRELAND
Mitsubishi Electric Europe
Westgate Business Park
Ballymount
Dublin 24
Ireland
Telephone: Dublin (01) 419 8800 Fax: Dublin (01) 419 8890 International code: 00 3531
36006282_issue_1
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