Ecosolar Solar Hot Water System Product guide

Unvented Direct & Indirect Solar
Hot Water Cylinders
Megaflo Product Guide
Contents
Product Specification......................................................................................................................................................................Page 3
Installation and Commissioning Instrucions................................................................................................................................Page 11
Maintenance and Servicing............................................................................................................................................................Page 27
User Guide.......................................................................................................................................................................................Page 36
Product Specification (1)
• Introduction
• Checklist
• General Requirements
• Water Supply
• Power Supply
• The Environment
• Specification and Dimensions
Unvented Hot Water Cylinder
3
Product Specification (1)
THE BENCHMARKtm SCHEME
Benchmarktm places responsibilities on both manufacturers and installers. The purpose is to ensure that customers are provided with the correct
equipment for their needs, that it is installed, commissioned and serviced in accordance with the manufacturer’s instructions by competent
persons and that it meets the requirements of the appropriate Building Regulations. The Benchmarktm Checklist can be used to demonstrate
compliance with Building Regulations and should be provided to the customer for future reference. Installers are required to carry out installation, commissioning and servicing work in accordance with the Benchmarktm Code of Practice which is available from the Heating and Hotwater
Industry Council who manage and promote the Scheme. Visit www.centralheating.co.uk for more information.
IMPORTANT NOTE TO USER: PLEASE REFER TO THE USER GUIDE SECTION ON PAGES 38 FOR IMPORTANT INFORMATION WITH
RESPECT TO THE BENCHMARK SCHEME
Introduction
Congratulations on your purchase of a Megaflo eco Solar unvented water heater. The Megaflo eco Solar 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 which is backed by a Lifetime guarantee* Its performance and insulation levels exceed the latest requirements of
Building Regulation Part L.
The Megaflo eco Solar 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 complete with all its necessary inlet and safety controls, electric immersion heater(s) and, for indirect units, a
cylinder thermostat, thermal cut-out, 2-port motorised valve and wiring centre.
Generally its pressure and flowrate performance will far exceed that from a comparable vented system, thermal store, multipoint instantaneous gas
heater, or combination boiler.
Please read and understand this product guide before starting work.
Please leave this product guide with the user following installation.
Component Checklist
Before commencing installation check that all the components for your Megaflo eco Solar unit are contained in the package. The following
components are supplied as standard with your Megaflo eco Solar unit:
•Factory fitted immersion heater(s) and thermal controls
• Cold Water Inlet Control Kit, comprising of:
• 3 Bar Pressure Reducing Valve (Fig 4) Page 12
• 8 Bar Pressure Relief Valve (Fig 5) Page 13
• Stop cock (Fig 6) Page 13
• Expansion Vessel (including wall mounting bracket)
•Factory fitted Temperature / Pressure Relief Valve (set at 90ºC / 1 Mpa (10bar))
• Tundish (included in Cold Water Combination Valve pack)
•Factory fitted Indirect Thermostat and Thermal cut-out (Indirect units only)
• T&P Relief Valve Insulation Set
• Drain Valve
• Wiring Centre (Indirect units only)
• 2-Port Motorised Valve (Indirect units only)
• Lifting handle
* See Terms and Conditions of guarantee on page 39
4
Unvented Hot Water Cylinder
Important: Please read and understand this product guide before installing the Megaflo eco Solar water heater. Incorrect installation may invalidate
the guarantee. This appliance is not intended for use by persons (including children) with reduced physical, sensory or mental capabilities, or lack of
knowledge and experience, unless they have been given supervision or instruction concerning the use of the appliance by a person responsible for
their safety. The Megaflo eco Solar must be Installed (Section 2), Commissioned (Section 2) and Maintained (Section 3) by a competent installer in
accordance with Building Regulation G3 (England and Wales), Technical Standard P3 (Scotland) or Building Regulation P5 (Northern Ireland) and the
Water Fitting Regulations (England and Wales) or Water Byelaws (Scotland). Following Installation and Commissioning, the operation of the heater
should be explained to the user (Section 4) and this product guide left with them for future reference.
Product Specification (1)
General Requirements
Siting the Megaflo eco (See Figure 1)
The Megaflo eco Solar 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. 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 (refer to Tables 3 and 4 on page 9 for unit weights). Pipe runs should be kept as short as possible for maximum economy.
Access to associated controls, immersion heaters and indirect controls should be possible for servicing and maintenance of the system.
Please do not install valves or pipework (except discharge pipe) within 50mm (2”) of the T&P relief valve to allow your insulation set to be fitted.
The insulation set is important to ensure heat and energy conservation. See section 2 (page 16) for more information.
To aid installation, the Megaflo eco Solar is provided with lifting points located in the base moulding and a lifting handle. The lifting handle should
be fully threaded onto the outlet boss before use. Once the Megaflo eco Solar is suitably positioned the lifting handle should be removed to allow
connection of the outlet pipework. The weights of the units are noted on the tables on page 9, see tables 3 and 4.
Figure 1 - Typical Schematic Installation Details
BALANCED COLD WATER
CONNECTION (IF REQUIRED)
TO HOT OUTLETS
3 BAR PRESSURE
REDUCING VALVE
T&P VALVE
SECONDARY RETURN
TAPPING (IF REQUIRED)
STOP COCK (IF USED
IN THIS POSITION)
AUXILIARY PRIMARY
RETURN
MAINS WATER
SUPPLY
AUXILIARY PRIMARY
FLOW
8 BAR PRESSURE RELIEF VALVE
ELEMENT/CONTROLS
HOUSING
EXPANSION
VESSEL
TUNDISH
SOLAR PRIMARY
RETURN
SOLAR PRIMARY
FLOW
DRAIN COCK
DISCHARGE PIPE
SOLAR CONTROLS
HOUSING
Unvented Hot Water Cylinder
5
Product Specification (1)
Outlet / Terminal Fittings (Taps, Etc.)
The Megaflo eco Solar can be used in conjunction with most types of terminal fittings. It is advantageous in many mixer showers to have balanced
hot and cold water supplies, in these instances the balanced cold water supply should be teed off the supply to the Megaflo eco Solar immediately
after the Cold Water Combination Valve (See Figure 7 page 14). Branches to cold drinking outlets should be taken before the valve.
Outlets situated higher than the Megaflo eco Solar unit will give outlet pressures lower than that at the heater, a 10m height difference will result in
a 0.1 Mpa (1 bar) pressure reduction at the outlet fitting.
NOTE: Accessories should have a rated operating pressure of at least 0.8 MPa (8 bar).
Limitations
The Megaflo eco Solar unvented water heater should not be used in any of the following instances:
•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.
• Gravity circulation primaries.
• Steam heating plant unless additional and appropriate safety devices are installed.
•Ascending spray type bidets or any other Class 5 back syphonage risk requiring that a Type AA, AB, AD or AG air gap be employed.
• 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.
•Areas where the water consistently contains a high proportion of solids, eg. suspended matter that could block the strainer, unless adequate
filtration can be ensured.
• The installation must be carried out in accordance with the relevant requirements of:
•The appropriate Building Regulations: either The Building Regulations (England), The Building Regulations (Scotland) or Building Regulations
(Northern Ireland).
• The Water Fittings Regulations (England and Wales) or Water Byelaws (Scotland).­
Water Supply
Bear in mind that the mains water supply to the property will be supplying both the hot and cold water requirements simultaneously. It is
recommended that the maximum water demand be assessed and the water supply checked to ensure this demand can be met.
NOTE: A high mains water pressure will not always guarantee high flow rates.
Wherever possible the main supply pipe should be in 22mm. The minimum mains water supply requirements should be 0.15 MPa (1.5 bar) working
pressure and 20 litres per minute flowrate.
At these values outlet flowrates may be poor if several outlets are used simultaneously, the higher the available pressure and flowrate the better the
system performance will be.
The Megaflo eco Solar has an operating pressure of 3 bar which is controlled by the 3 Bar Pressure Reducing Valve. The 3 Bar Pressure Reducing
Valve can be connected to a maximum mains supply pressure of 1.6 MPa (16 bar). The water supply must be of wholesome water quality (Fluid
Category 1 as defined by the Water Supply Regulations 1999).
The Megaflo eco is to be used for the storage of wholesome water (max. 250mg/l chloride).
Electrical Supply
WARNING: THIS APPLIANCE MUST BE EARTHED. IT IS SUITABLE FOR A.C. SUPPLY ONLY. ELECTRICAL INSTALLATION MUST BE CARRIED
OUT BY A COMPETENT ELECTRICIAN AND BE IN ACCORDANCE WITH THE LATEST I.E.E. WIRING REGULATIONS.
ENSURE THE ELECTRICAL SUPPLY IS SWITCHED OFF BEFORE MAKING ANY CONNECTIONS TO THE MEGAFLO ECO SOLAR
The Environment
This product is made from many recyclable materials, therefore at the end of its useful life it 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 HCFC/CFC free polyurethane foam.
6
Unvented Hot Water Cylinder
Product Specification (1)
Specifications and Dimensions
Outline Specifications
Maximum mains water supply pressure (to 3 Bar Pressure )
1.6 MPa (16 bar)
Operating pressure (Pressure reducing valve set pressure – non adjustable) 0.3 MPa (3 bar)
Expansion relief valve set pressure
0.8 MPa (8 bar)
Temperature / Pressure Relief Valve set temp / pressure
90ºC / 1MPa (10 bar)
Immersion heater rating (a.c. supply only)
3kW @ 240V 50Hz
2.8kW @ 230V 50Hz
Outer casing:
White textured plastic coated 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 60mm.
Pipe connections:
All connections accept 22mm outside diameter pipe – compression nuts and olives supplied. Thread rate is 3/ ” BSP male parallel to accept standard
3
/ ” BSP female fittings if required.
4
4
Safety features:
Direct units –
Manually resettable thermal cut-out on each heating element
Factory fitted Temperature / Pressure Relief Valve
Indirect units –
Manually resettable thermal cut-out on heating element
Manually resettable thermal cut-out for primary heating. Must be wired in conjunction with 2-port motorised valve supplied
Factory fitted Temperature / Pressure Relief Valve
The pace of product development is such that we reserve the right to change product specifications without
notice. We do, however, strive to ensure that all information in this leaflet is accurate at the time of publication.
Table 1 - Standing Heat-loss
NOMINAL
CAPACITY
(LITRES)
170
190
210
250
260
300
STANDING HEAT LOSS
PER DAY
(kWh/24h)
1.25
1.32
1.41
1.56
1.63
1.84
PER YEAR
(kWh/24h)
456.25
481.80
514.65
569.40
594.95
671.60
Unvented Hot Water Cylinder
7
Product Specification (1)
600
Fig 2 - Megaflo eco Solar Direct
73
A
27°
30°
47°
414
373
454
C
B
D
45°
600
Fig 3 - Megaflo eco Solar Indirect
73
8
Unvented Hot Water Cylinder
414
373
454
C
F
E
D
A
47°
27°
30°
45°
SIZE
TYPE
170
190
210
210
260
250
300
300
Direct
Indirect
Direct
Indirect
Direct
Indirect
Direct
Indirect
A
1229
1387
1489
1489
1802
1738
2053
2053
B
1103
1167
1444
-
DIMENSIONS
C
794
814
829
949
888
1068
983
1255
(m m )
D
925
1020
1184
1184
1441
1378
1693
1693
E
925
1095
1258
1573
F
735
1039
1142
1438
Product Specification (1)
Table 2 - Dimensions
Table 3 - Direct
UNIT WEIGHT (kg)
SIZE
170
HEAT UP TIMES (mins)
EMPTY
FULL
AUXILLARY
VOLUME (L)
37.8
207.8
120
126
N/A
N/A
150
LOWER (3kW)
UPPER +
LOWER (6kW)
UPPER BOOST
(3kW)
210
42.5
252.5
140
75
60
260
47.3
307.3
170
178
89
60
300
61.5
361.5
200
220
110
60
Table 4 - Indirect
UNIT WEIGHT (kg)
SIZE
EMPTY
FULL
AUXILLARY
VOLUME (L)
AUXILLARY COIL SPECIFICATIONS
SURFACE
(sqm)
HEAT UP
(mins)
RECOVERY
(mins)
RATING
(kW)
190
45.5
235.5
120
0.61
21
14.5
18.0
210
47.5
257.5
120
0.68
21
14.5
18.0
250
56.5
306.5
145
0.73
24.5
20
18.7
300
66.5
366.5
175
0.79
22.5
19
24.5
note
Auxiliary coil heating performance based on a primary flow rate of 15L/min at 80°C.
Temperature rise is from 15°C to 60°C. Heating times using the solar primary circuit will depend on the amount
of solar radiation, sunshine hours, collector panel type, size and orientation so will be variable.
Unvented Hot Water Cylinder
9
Product Specification (1)
10
NOTES.
Unvented Hot Water Cylinder
Product
Specification (1)
Installation and
commissioning Instructions (2)
• General Installation
• Indirect Model
• Direct Model
• Commissioning
Unvented Hot Water Cylinder
11
General Installation
Pipe Fittings
All pipe connections to the Megaflo eco Solar are made via 22mm compression fittings directly to the unit (nuts and olives supplied). The fittings
are also threaded 3/ ” BSP male parallel should threaded pipe connections be required.
4
Cold Water Supply
A 22mm cold water supply is recommended, however, if a 15mm (1/ ”) supply exists which provides sufficient flow (see Section1 Page 6 “Water
Supply”) this may be used. More flow noise may be experienced from small bore pipes due to the increased water velocity through them.
Installation and
commissioning Instructions (2)
2
The Cold Water Inlet Control kit supplied with the Megaflo eco Solar incorporates a full flow isolating valve which will enable the Megaflo eco
Solar to be isolated from the mains supply for maintenance or servicing. To close the valve the blue handle should be turned so that it lies at 90º to
the direction of flow. To open, turn the handle so that it lies parallel to the direction of flow.
3 Bar Pressure Reducing Valve (See Figure 4 )
The 3 Bar Pressure Reducing Valve can be connected anywhere on the cold water mains supply prior to the Megaflo eco Solar unit. 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.
The 3 Bar pressure Reducing Valve can be installed as a complete one-piece unit or incorporating the stopcock see Fig 6. The valve incorporates a
factory set, non-adjustable Pressure Reducer / Strainer and a single Check Valve. The valve can be fitted in any orientation to suit the installation,
however, ensure that the Valve is installed with the direction of flow arrows (stamped on the side of the brass body) pointing towards the Megaflo
eco Solar heater.
If a balanced pressure cold water supply is required to a thermostatic shower mixer valve this may be teed off the supply to the Megaflo eco Solar
immediately after the 3 Bar Pressure Reducing Valve (See Figure 7, page 14).
Figure 4 - 3 Bar Pressure Reducing Valve
Pressure reducing valve
cartridge (3 Bar)
Take note of flow
direction
Mains in
Outlet to Megaflo
eco Solar
22mm compression connection
12
Unvented Hot Water Cylinder
8 Bar Pressure Relief Valve (See Figure 5)
This should be installed between the 3 bar Pressure Reducing Valve and the Megaflo eco Solar cylinder. Should a balanced pressure cold water draw off supply be required
for the cold water outlets, this should be taken off between the 3 bar Pressure Reducing Valve and 8 bar Pressure Relief Valve (see Figure 7, page 14).
Branches to drinking water outlets should be taken before the Pressure Relief Valve to avoid the possibility of warm expanded water being
drawn from the tap.
Figure 5 - 8 Bar Pressure Relief Valve
Pressure Relief Valve
discharge connection
From cold water
Combination Valve
Outlet to Megaflo
eco Solar
Pressure Relief Valve
“TEE” ( incorporates
Check Valve )
Installation and
commissioning Instructions (2)
Take note of flow
direction
22mm compression connection
Figure 6 - Valve set can be grouped two ways
Stopcock can be grouped with either
3 Bar Pressure Reducing Valve or
8 Bar Pressure Relief valve on the
inlet to either valve only
Stopcock
8 Bar Pressure Relief
Valve
3 Bar Pressure
Reducing Valve
Unvented Hot Water Cylinder
13
14
Unvented Hot Water Cylinder
KEY
MCWS =
HWS =
SC =
DOC =
Mains cold water supply
Hot water service
Stop Cock / Isolating Valve
Drain Off Cock
Isolating/Regulating
Valves, as required
Balanced HWS and
MCWS to bathrooms,
showers, cloakrooms,
etc
DOC
Tundish
Temperature/Pressure
Relief Valve
Balanced cold water
draw-off
Discharge pipe to atmosphere
(see page 18 “Discharge Pipework”)
DOC DOC
Megaflo eco
Solar
HWS supply
Incoming Cold
Water Main
MCWS to Kitchen
(unbalanced cold
mains supply)
Expansion Vessel
SC
DOC
SC
3 Bar Pressure Reducing
Valve incorporating
Pressure Reducing Valve,
Strainer,and Check Valve.
(Stop cock can be fitted
here)
8 Bar Pressure Relief
Valve (combined
Expansion Relief
Valve/Check Valve)
Installation and
commissioning Instructions (2)
Figure 7 - Schematic installation diagram using 3 Bar Pressure Reducing Valve in conjunction
with 8 Bar Pressure Relief Valve
Drain Tap
A drain tap is supplied and should be installed in the cold water supply to the Megaflo eco Solar unit between the 8 Bar Pressure Relief Valve and
the heater at as low a level as possible (see Figure 1, page 5). 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). The drain tap supplied provides very
good water flow control and blanking cap for extra security.
Outlet Pipework
Ideally the pipework from the Megaflo eco Solar 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.
Expansion Vessel
The Expansion Vessel accomodates expansion that results from heating the water inside the unit. The unit is pre-charged at 0.35MPa (3.5Bar).
The Expansion Vessel must be connected between the 8 Bar Pressure Relief Valve and the Megaflo eco Solar cylinder (See Figure 1). The location
of the Expansion Vessel should allow access to re-charge 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.
Secondary Circulation
If a secondary circulation system is required it is recommended that it be connected to the Megaflo eco Solar as shown in Figure 8. To achieve
this the 1/2” BSP Sensor Pocket must be removed. 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 additional expansion volume to the system by fitting an external expansion vessel to the secondary circuit. This should be
done if the capacity of the secondary circuit exceeds 10 litres.
Pipe capacities (copper)
15mm o/d = 0.13 litres per metre run (10 litres = 77m)
22mm o/d = 0.38 litres per metre run (10 litres = 26m)
28mm o/d = 0.55 litres per metre run (10 litres = 18m)
Note:
Secondary circulation is NOT recommended for direct electric units
Figure 8 - Secondary Circulation Connection
Installation and
commissioning Instructions (2)
NOTE: DO NOT USE THE POTABLE WATER EXPANSION VESSEL SUPPLIED WITH THE MEGAFLO ECO SOLAR FOR ANY OTHER
PURPOSE. IT MUST NOT BE USED IN PLACE OF THE SOLAR PRIMARY SYSTEM EXPANSION VESSEL.
TO HOT OUTLETS
CHECK VALVE
SECONDARY RETURN
COLD WATER
INLET
WRAS APPROVED
BRONZE PUMP
Unvented Hot Water Cylinder
15
T&P Relief Valve Insulation
A set of insulating components is supplied with the Megaflo eco Solar water heater and should be installed to gain maximum heat and energy
saving benefits. See Figure 9 (below), for installation instructions.
Warnings
i) Under no circumstances should the factory fitted Temperature /Pressure Relief Valve be removed other than by authorised Heatrae Sadia personnel.
To do so will invalidate any guarantee or claim.
ii) The Cold Water Inlet Control kit must be fitted to the mains water supply to the Megaflo eco Solar unit.
Installation and
commissioning Instructions (2)
iii)No control or safety valves should be tampered with.
iv)Water may drip from the discharge pipe of the pressure relief device (Expansion Valve) and this pipe must be left open to atmosphere. The
discharge pipe should not be blocked or used for any other purpose.
Figure 9 - INSTALLATION OF T&P INSULATION SET
IMPORTANT INFORMATION:
HOW TO INSULATE YOUR T&P RELIEF VALVE
TO SAVE HEAT AND ENERGY A SET OF INSULATING PARTS FOR
THE T&P RELIEF VALVE HAVE BEEN SUPPLIED WITH THIS WATER
HEATER. INSTALL THE HEATER FIRST THEN FIT THE INSULATING
PARTS BY FOLLOWING THE DIAGRAMS BELOW.
B
A
T&P RELIEF
VALVE
DISCHARGE
PIPEWORK
LEFT HAND
INSULATING PIECE
RIGHT HAND
INSULATING PIECE
TUNDISH
D
C
PLASTIC COVER
16
Unvented Hot Water Cylinder
DISCHARGE PIPE
CLIP INTO
PLACE !
The following extract is taken from the latest G3 Regulations
Discharge pipes from safety devices
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.
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
(see Diagram 1).
Note:
To comply with the Water Supply (Water Fittings) Regulations, the tundish should incorporate a suitable air gap.
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
3.55
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); 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 and the worked example.
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)
(b)
(c)
Note:
( d)
1.
2.
Installation and
commissioning Instructions (2)
Tundish
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;
be a separate branch pipe with no sanitary appliances connected to it;
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
be continuously marked with a warning that no sanitary appliances should be connected to the pipe.
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.
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.
Unvented Hot Water Cylinder
17
Discharge Pipework
It is a requirement of Building Regulations 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 Regulations. Building Regulation G3 Requirements and Guidance section 2 (page 17) are reproduced in the following sections.
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.
The water may drip from the discharge pipe of the pressure relief device and that 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.
Installation and
commissioning Instructions (2)
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:
1) Discharge pipe-work D2 can now be a plastic pipe but only pipes that have been tested to a minimum110°C must be used.
2) Discharge pipe D2 can now be plumbed in the soil stack but only soil stacks that can handle temperatures of 99°C or greater should be used.
Table 5 Sizing of copper discharge pipe “D2” for common T&P Relief Valve 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
RESISTANCE CREATED BY
EACH ELBOW OR BEND
G 1/2
15mm
G 3/4
22mm
G1
28mm
22mm
28mm
35mm
28mm
35mm
42mm
35mm
42mm
54mm
UP TO 9m
UP TO 18m
UP TO 27m
UP TO 9m
UP TO 18m
UP TO 27m
UP TO 9m
UP TO 18m
UP TO 27m
0.8m
1.0m
1.4m
1.0m
1.4m
1.7m
1.4m
1.7m
2.3m
Figure 10 - Schematic discharge pipe arrangement
Safety device
(e.g. Temperature
relief valve)
Metal discharge pipe (D1) from
Temperature relief valve to tundish
600mm maximum
Tundish
300mm
minimum
Discharge pipe (D2) from tundish,
with continuous fall. See Building
Regulation G3 section 3.56,
Table 4 and worked example
Discharge below
fixed grating
(Building Regulation
G3 section 3.61 gives
alternative points
of discharge)
Fixed grating
Trapped
gully
18
Unvented Hot Water Cylinder
Worked example of discharge pipe sizing
The example on page 18 is for a G1/ temperature relief valve with a discharge pipe (D2) having 4 No. elbows and length of 7m from the tundish to
the point of discharge.
2
From Table 5:
Maximum resistance allowed for a straight length of 22mm copper discharge pipe (D2) from a G1/ temperature relief valve is 9m.
2
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/ temperature relief valve equates to 18m.
2
Subtract the resistance of 4 No. 28mm elbows at 1m each = 4m
As the actual length is 7m, a 28mm (D2) copper pipe will be satisfactory.
INDIRECT MODEL
Boiler Selection
The Megaflo eco Solar Indirect models are supplied with an auxiliary heating coil and is suitable for use with most gas or oil fired boilers compatible
with unvented systems i.e. fitted with a temperature control thermostat and thermal cut-out. If in doubt consult the boiler manufacturer. 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 boiler used can either be a sealed system or open vented type, maximum primary circuit pressure
0.3Mpa (3 bar). The primary flow from the boiler MUST be pumped. Gravity circulation will not work due to the special design of the primary heat
exchanger. It is recommended that an air bleed point or automatic air vent is incorporated in the primary return pipework close to the Megaflo eco
Solar unit. The boiler flow temperature should usually be set to 82ºC (maximum flow temperature to primary heat exchanger 89ºC). The boiler
cannot be vented through the Megaflo eco Solar unit.
Indirect Thermal Cut-Out And 2-Port Motorised Valve
To comply with Building Regulations, and to prevent the Megaflo eco Solar from overheating the 2-port motorised valve supplied MUST be fitted to
the primary flow to the indirect coil (see Figure 11 below).
Installation and
commissioning Instructions (2)
Therefore the maximum permitted length equates to: 14m
Figure 11 - Primary connections to indirect units
TO HOT OUTLETS
AIR VENT
(MUST BE AT THE HIGHEST
POINT OF THE SYSTEM)
PRIMARY RETURN
TWO PORT MOTORISED VALVE (SUPPLIED)
COLD WATER INLET
PRIMARY FLOW
SOLAR PRIMARY RETURN
SOLAR PRIMARY FLOW
Unvented Hot Water Cylinder
19
Wiring
Unvented Hot Water Cylinder
All electrical wiring should be carried out by a competent electrician and be in accordance with the latest I.E.E. Wiring Regulations.
Installation and
commissioning Instructions (2)
The Megaflo eco Solar Indirect combined thermostat and thermal cut-out are factory pre-wired. The 2-port motorised valve supplied MUST be
wired in series with the Indirect controls such that the power supply to the valve is interrupted should either the Thermostat or Thermal cut-out
operate. The Figures 13 and 14 (page 21) detail the wiring required between these controls and the motorised valve. Wiring to external controls
is made via the terminal block fitted. The cable should be routed through the aperture in the terminal cover and secured using the cable grip
provided. The Indirect Thermal cut-out MUST NOT be bypassed.
Heating System Controls
The controls provided with the Megaflo eco Solar will ensure the safe operation of the Megaflo eco Solar within a central heating system. Other
controls will be necessary to control the space heating requirements and times that the system is required to function. Depending on the boiler
selected, heating circuit design and controls used it may be beneficial to incorporate a system bypass in the heating system pipework.
The Megaflo eco Solar is compatible with most heating controls, examples of electrical circuits are given in Figures 13 and 14, page 21. However,
other systems may be suitable, refer to the controls manufacturers’ instructions, supplied with the controls selected, for alternative
system wiring schemes.
Immersion Heater(s)
The Megaflo eco Solar indirect units (Indirect models) are supplied with an immersion heater which can be used as an alternative heat source
should the boiler supply need to be isolated from the Megaflo eco Solar unit. The immersion heater is located within the controls housing. Refer to
Section 2, page 22 “Wiring and Operation” for details of wiring and operation of the immersion heater, 210 litre models and above are supplied
with a second blanked off boss which can be used for the connection of a second immersion heater should this be required.
To remove the blanking plug:
Ensure the cylinder is drained of water first. Open the cover to the upper immersion heater boss. Unscrew the brass backnut using the key spanner
provided with the unit. Remove the blanking plate and sealing gasket from the boss.
Fitting additional immersion heater:
Insert the immersion heater and sealing gasket into the upper boss. Ensure that the sealing gasket is not displaced when inserting. It may be helpful
to support the immersion heater using a round shafted screwdriver inserted into one of the thermostat pockets. Hand tighten the brass backnut.
Secure the immersion heater in position by tightening with the key spanner provided. If an additional immersion heater and thermostat assembly is
required order part no. 95:970:554
Figure 12 - Indirect Wiring layout
Control Housing Details
Element Connections
Indirect control
wiring
20
Unvented Hot Water Cylinder
1
2
3
L
N
1.5mm² 3 Core
HOFR sheathed
cable
Figure 13 - 2 port valve in conjunction with a 3 port mid-position valve system (“Y” Plan)
MEGAFLO ECO INDIRECT
THERMAL CONTROLS
(SUPPLIED FITTED)
PROGRAMMER
KEY
Bl
Br
G
O
GY
DHW
HTG
L
N
1
2
HTG
ON
DHW
ON
DHW
OFF
4
5
6
MEGAFLO ECO (DHW) 2-PORT
VALVE (SUPPLIED)
Bl Br G O GY
1
2
3
7
8
9 10 11 12 13 14 15 16
Bl
W G
BLUE
BROWN
GREY
ORANGE
GREEN/YELLOW
DOMESTIC HOT WATER
HEATING
Installation and
commissioning Instructions (2)
3
WIRING CENTRE
(SUPPLIED)
L
N
1
3
2
ROOM STAT
O GY
N
N
L
L
PUMP
BOILER
3-PORT MID POSITION VALVE
NOTES:
1. A DOUBLE POLE ISOLATING SWITCH MUST BE INSTALLED IN THE MAINS SUPPLY.
2. ALL EARTH CONNECTIONS MUST BE LINKED BACK TO THE MAINS EARTH SUPPLY.
3. ASSUMES BASIC BOILER WITH EXTERNAL PUMP.
4. USE COPPER LINKS SUPPLIED TO MAKE CONNECTIONS BETWEEN TERMINALS.
5. DO NOT MOUNT WIRING CENTRE ON CYLINDER.
6. THE ABOVE DIAGRAM IS FOR GUIDANCE ONLY, HEATRAE SADIA ACCEPT NO LIABILITY FOR ANY LOSS OR DAMAGE ARISING FROM ANY ERRORS OR OMISSIONS.
THAT MAY BE INADVERTENTLY CONTAINED WITHIN THIS DIAGRAM. THE VARIOUS EQUIPMENT MANUFACTURERS SHOULD BE CONSULTED TO CONFIRM THE
CORRECT OPERATION OF THEIR PRODUCTS WITHIN THE SYSTEM.
Figure 14 - 2 x 2 port valve system (“S”Plan)
MEGAFLO ECO INDIRECT
THERMAL CONTROLS
(SUPPLIED FITTED)
PROGRAMMER
KEY
Bl
Br
G
O
GY
DHW
HTG
L
N
1
2
HTG
ON
DHW
ON
4
5
MEGAFLO ECO (DHW)
ZONE VALVE
(SUPPLIED)
1
2
3
8
9
10 11 12 13 14 15 16
Br
G
O GY
Bl
Br
G
O GY
BLUE
BROWN
GREY
ORANGE
GREEN/YELLOW
DOMESTIC HOT WATER
HEATING
3
6
7
WIRING CENTRE
(SUPPLIED)
L
N
1
3
2
ROOM STAT
Bl
ZONE VALVE (HTG)
N
L
BOILER
N
L
PUMP
NOTES:
1. A DOUBLE POLE ISOLATING SWITCH MUST BE INSTALLED IN THE MAINS SUPPLY.
2. ALL EARTH CONNECTIONS MUST BE LINKED BACK TO THE MAINS EARTH SUPPLY.
3. USE COPPER LINKS SUPPLIED TO MAKE CONNECTIONS BETWEEN TERMINALS.
4. DO NOT MOUNT WIRING CENTRE ON CYLINDER.
5. THE ABOVE DIAGRAM IS FOR GUIDANCE ONLY, HEATRAE SADIA ACCEPT NO LIABILITY FOR ANY LOSS OR DAMAGE ARISING FROM ANY ERRORS OR OMISSIONS.
THAT MAY BE INADVERTENTLY CONTAINED WITHIN THIS DIAGRAM. THE VARIOUS EQUIPMENT MANUFACTURERS SHOULD BE CONSULTED TO CONFIRM THE
CORRECT OPERATION OF THEIR PRODUCTS WITHIN THE SYSTEM.
Unvented Hot Water Cylinder
21
Direct Model
Immersion Heater(s)
The Megaflo eco Solar Direct is supplied with either one (D models) or two (DD models) factory fitted immersion heaters. Each immersion heater is
rated 3kW at 240V.
Installation and
commissioning Instructions (2)
To remove the immersion heater:
Open the cover to the upper immersion heater. Disconnect the two wires to element tabs, pull out the two thermostat capillaries (remember which
way round they go) and move out of the way. Unscrew the brass backnut using the key spanner provided. Remove the immersion heater assembly
and sealing gasket from the boss.
Replacement:
Insert the immersion heater and sealing gasket into the required boss. Ensure that the sealing gasket is not displaced when inserting. It may be
helpful to support the immersion heater using a round shafted screwdriver inserted into the thermostat pocket. Hand tighten the brass backnut.
Secure the immersion heater in position by tightening with the key spanner provided. Replace the thermostat capillaries, spiral one in first (making
sure capillary tubes do not touch element legs). Reconnect element wires from thermostat.
If an additional immersion heater is required order part no. 95:970:554.
Wiring (See Figure 16)
All electrical wiring should be carried out by a competent electrician and be in accordance with the latest I.E.E. Wiring Regulations. Each circuit
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(s) should be wired in accordance with Figure 15, page 23 . The immersion heaters MUST be earthed. The supply cable should
be 1.5mm2 3 core HOFR sheathed and must be routed through the cable gland provided with the outer sheath of the cable firmly secured by
tightening the screw on the cable gland. Replace the immersion heater cover(s) before operating ensuring that the threaded edge clip is in position
to provide a suitable thread for the cover screw.
DO NOT OPERATE THE IMMERSION HEATER(S) UNTIL THE MEGAFLO ECO SOLAR HAS BEEN FILLED WITH WATER.
Operation
See Figure 16, page 23 for details on how to adjust the temperature setting of the heater. The thermostat incorporates a thermal cut-out that will
switch off the immersion heater in the event of a thermostat failure. The thermal cut-out reset button position is indicated on Figure 16, page 23.
DO NOT BYPASS THE THERMAL CUT-OUT IN ANY CIRCUMSTANCES.
Access to Control Unit:
LUGS
Disconnect from mains supply before removing any covers.
Removing the Control Cover:
• Unscrew the large screw using a flat ended screw driver.
• Lift from bottom of cover at point indicated until cover comes
away freely
Replacing the Control Cover:
LIFT OFF
• Tilt and align the top 2 lugs in the holes indicated
• Firmly press the cover until it “snaps” back in place.
• Tighten the large screw ( DO NOT OVER TIGHTEN ).
LIFT FROM THIS POINT
REPLACE
22
Unvented Hot Water Cylinder
Safety
DO NOT BYPASS THE THERMAL CUT-OUT(S) IN ANY CIRCUMSTANCES
DISCONNECT FROM THE MAINS SUPPLY BEFORE REMOVING ANY COVERS
NEVER ATTEMPT TO REPLACE AN IMMERSION HEATER OTHER THAN WITH THE RECOMMENDED Heatrae Sadia MEGAFLO ECO SOLAR SPARE
PART
Figure 15 - Schematic wiring diagram - Direct immersion heaters, with adjustment details
Direct Wiring Layout
Installation and
commissioning Instructions (2)
N
L
1.5mm² 3 Core
HOFR sheathed
cable
Figure 16 - Adjustment details
THERMAL CUT-OUT RESET BUTTON
SPINDLE POSITIONS
= MINIMUM TEMP
= MAXIMUM TEMP
= APPROX 60 °C
ROTATE SPINDLE CLOCKWISE
FOR TEMPERATURE INCREASE
AND COUNTER CLOCKWISE
FOR TEMPERATURE DECREASE
TEMPERATURE ADJUSTING
SPINDLE
Unvented Hot Water Cylinder
23
sOLAR primary
cONNECTION TO THE sOLAR PRIMARY CIRCUIT
The lower (Solar) coil of the Megaflo eco Solar 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.
Installation and
commissioning Instructions (2)
CONTROL OF SOLAR PRIMARY CIRCUIT
Temperature control of the Megaflo eco Solar 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 Megaflo eco Solar (see figure 17 ) 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 Figure 17). 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.
The Megaflo eco Solar cylinders are fitted with two additional sensor pockets for use with solar controllers. A second 10mm pocket is supplied
within the bottom Solar Control assembly and a 8mm pocket is supplied near the T&P valve, this pocket can be removed and used as a secondary circulation connection if needed, on Indirect models only
Figure 17 - Solar wiring layout
THERMAL CUT-OUT
PROBE
CONTROL ASSEMBLY
SOLAR CONTROLLER
POWER SUPPLY TO
SOLAR CONTROLLER
L
N
E
24
Unvented Hot Water Cylinder
Commissioning
Filling and flushing the Megaflo eco Solar
Ensure that all fittings and immersion heaters are correctly fitted and tightened. An immersion heater key spanner is provided to aid in tightening
the immersion heater(s).
i)Open a hot tap furthest from the Megaflo eco Solar.
ii)Open the isolating valve on the 3 Bar Pressure Reducing Valve by turning the blue handle on the stop cock (if fitted in this position) so that it lies
parallel to the direction of flow. Open the mains stop cock to fill the unit. When water issues from the tap, allow to run for a few minutes to
thoroughly flush through any residue, dirt or swarf, then close tap.
iii)Open successive hot taps to purge any air from the system.
iv)Check all connections for leaks and rectify as necessary.
v)The Strainer housed within the 3 Bar Pressure Reducing Valve should be cleaned to remove any debris that may have been flushed through the
main supply pipe. Refer to Section 3, Page 28 for instructions on how to do this.
ii)Repeat for the 8 Bar Pressure Relief Valve (see Figures 5 and 6, page 13).
NOTE: The water discharged may be very hot
Indirect Units (Solar Primary Circuit)
Fill the solar primary circuit following the instructions provided with the solar hydraulic controls. The cylinder temperature control sensor probe
supplied with the solar differential temperature controller must be inserted into the pocket in the lower controls housing and its cable securely
clamped. Heating by the solar primary circuit is controlled by the solar differential temperature controller, refer to the manufacturer’s installation
instructions for details of how to set up and commission the solar primary circuit. The solar controller should be programmed to give a maximum
storage temperature in the Megaflo eco Solar of 70oC although 60oC is recommended to minimise scaling.
Direct Units
Switch on the electrical supply to the immersion heater(s) and allow the unit to heat up. Check that the thermostat operates correctly. A storage
temperature of approx. 60ºC is recommended. If necessary the temperature can be adjusted by inserting a flat bladed screwdriver in the adjustment
knob on top of the immersion heater thermostat and rotating clockwise (see Figure 16, page 23). The full adjustment represents a temperature
range of between 12º and 68ºC. Check that no water is discharged from either the Expansion Valve or Temperature and Pressure Relief Valve during
the heating cycle.
Installation and
commissioning Instructions (2)
Check the operation of the Safety Valves
i)Slowly, manually open (turn black knob on end counter-clockwise), for a few seconds, the Temperature and Pressure Relief Valve (T&P Valve)
situated on the Megaflo eco Solar unit (see Figure 1, page 5). Check water discharged runs freely away through the tundish and discharge
pipework. Close valve, ensure water flow stops and valve reseats correctly.
Indirect Units
Fill the indirect (primary) circuit following the boiler manufacturer’s commissioning instructions. To ensure the primary heating coil in the Megaflo
eco Solar is filled the 2-port motorised valve (supplied) should be manually opened by moving the lever on the motor housing to the MAN OPEN
position. When the primary circuit is full return the lever to the AUTO position. Vent any trapped air by opening the air bleed.
Switch on the boiler, ensure the programmer is set to Domestic Hot Water. Allow the Megaflo eco Solar unit to heat up and check that the indirect
thermostat and 2-port motorised valve operate correctly. A storage temperature of approx. 60ºC is recommended. If necessary the temperature can
be adjusted by inserting a flat bladed screwdriver in the adjustment knob (located on the front of the thermostat mounting bracket see Figure 16,
page 23 ) and rotating clockwise to increase the temperature or counter clockwise to reduce the temperature. The minimum thermostat setting is
12ºC. The adjustment range on the combined thermostat and thermal cut-out is 12°C-68°C
Check that no water is discharged from either the Expansion Valve or Temperature and Pressure Relief Valve during the heating cycle.
Benchmarktm Log Book
On completion of the installation and commissioning procedures detailed in this Product Guide the BenchmarkTM “Installation, Commissioning
and Service Record Log, pages 34 and 35” should be completed and signed off by the competent installer or commissioning engineer in the
relevant sections. The various system features, location of system controls, user instructions and what to do in the event of a system failure should
be explained to the customer. The customer should then countersign the BenchmarkTM commissioning checklist (page 34) to accept completion.
The Service Record should be filled in when any subsequent service or maintenance operation is carried out on the Megaflo eco Solar unit (See
Maintenance and Servicing, page 35).
Unvented Hot Water Cylinder
25
Installation and
commissioning Instructions (2)
notes.
26
Unvented Hot Water Cylinder
maintenance and
servicing (3)
• Maintenance
• Fault Finding
• Servicing
• Spares
• Benchmark
Unvented Hot Water Cylinder
27
Maintenance
Maintenance requirements
To ensure the continued optimum performance of the Megaflo eco Solar it should be regularly maintained. This is of particular importance in
hard water areas or where the water supply contains particulate matter. Maintenance should be carried out by a competent person and any
replacement parts used should be authorised Megaflo eco Solar spare parts. It is recommended that maintenance is carried out every 12 months
and includes the checks detailed below.
In hard water areas consideration should be given to periodically descaling the immersion heater elements. To do this the Megaflo eco Solar unit
will need to be drained, details below list how to drain the unit and remove the immersion heater(s).
Check operation of Safety Valves
Slowly open the Temperature and Pressure Relief Valve by twisting its cap 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: The water discharged may be very hot.
Repeat the procedure for the 8 Bar Pressure Relief Valve.
Clean the strainer
The strainer is incorporated within the Pressure Reducing Valve housing of the Cold Water Combination Valve (see Figure 17, page 31). To inspect
and clean the strainer:
i)Turn off the isolating valve on the 3 Bar Pressure Reducing Valve by turning the blue handle (if fitted in this position) so it lies 90º to the direction
of flow or main stop cock to the house.
ii)Open the lowest hot tap in the system to relieve the system pressure.
iii)Using a spanner unscrew the pressure reducing cartridge and remove the moulded housing. The strainer will be removed with the cartridge.
iv)Wash any particulate matter from the strainer under clean running water.
v) Replace the strainer and screw the Pressure Reducing Valve cartridge into the moulded housing.
vi)Close hot tap, turn on isolating valve by turning handle so it lies parallel to the direction of flow. Check for leaks.
maintenance and
servicing (3)
Draining the Megaflo eco Solar unit
Switch off the electrical supply to the immersion heater(s) and shut down the boiler on indirect units. Turn off the mains water supply
to the Megaflo eco Solar unit. Attach a hosepipe to the drain cock having sufficient length to take water to a suitable discharge point below the
level of the unit, at least one metre below the unit is recommended. Open hot water tap nearest to the Megaflo eco Solar to relieve the system
pressure. Open drain cock. If water fails to drain from the Megaflo eco Solar vent the unit by manually opening the Temperature / Pressure Relief
Valve.
Descaling immersion heater(s)
Open the cover(s) to the immersion heater housing(s) and disconnect wiring from immersion heater(s). Remove the thermostat capillaries, 2 or
4 depending on which unit being serviced. Unscrew immersion heater backnut(s) and remove immersion heater from the unit. A key spanner is
supplied with the Megaflo eco Solar unit for easy removal / tightening of the immersion heater(s). Over time the immersion heater gasket may
become stuck to the mating surface. To break the seal insert a round shafted 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(s). 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(s) ensuring the lower (right angled) element hangs vertically downwards towards the base of the unit. It may be helpful
to support the immersion heater using a round shafted screwdriver inserted into one of the thermostat pockets whilst the backnut is tightened.
Replace the thermostat(s) by carefully plugging the two male spade terminations into the corresponding terminations on the element.
Rewire the immersion heater(s) in accordance with Figure12, page 20 or Figure 15, page 23. Close and secure terminal cover(s).
Expansion Vessel Charge Pressure
Remove the dust cap from the top of the expansion vessel. Check the charge pressure using a tyre pressure gauge. The charge pressure (with the
system depressurised) should be 0.3MPa (3 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.
Refilling system
DO NOT switch on the immersion heater(s) or boiler until the system has been completely refilled.
Close the drain tap. With the hot tap open, turn on mains water supply. When water flows from the hot tap allow to flow for a short while to
purge air and to flush through any disturbed particles. Close hot tap and then open successive hot taps in system to purge any air. The electrical
supply can now be switched on.
BenchmarkTM
On completion of any maintenance or service of the Megaflo eco Solar, the BenchmarkTM “Installation, Commissioning and Service Record”
should be filled in to record the actions taken and the date the work was undertaken. (Section 3, page 34 & 35)
28
Unvented Hot Water Cylinder
Fault finding
The Fault Finding chart (Table 6) will enable operational faults to be identified and their possible causes rectified. Any work carried out on the
Megaflo eco Solar 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 the Megaflo eco Solar Service Department ,Section 4, page 40.
Table 6 - Fault Finding Chart
FAULT
N o ho t w ate r flow
W a ter from hot tap s is c o ld
POSSIBLE CAUSE
REMEDY
1. M a in s w a t e r s u pp ly o ff.
1 . C h ec k and op en s top c oc k .
2. S tra in er bloc k e d.
2 . Turn o ff w a ter s u pp ly . R em ove s tra in er
a nd c le an (s ee page 28).
3. C old W ater C om bination
V alve inc orrec tly fitted .
3 . C h ec k and refit as re qu ired .
1. B A C K U P im m e rs ion h ea te r
no t s w itc hed on.
1 . C h ec k and s w itc h o n.
2. B A C K U P im m e rs ion h ea te r 2 . C h ec k . R e s e t b y pu s h in g bu tto n.
(Figure 16, page 23)
the rm al c ut-ou t h as ope rated .
3 . C h ec k . S e t to a D o m e s tic H ot W a te r
p ro gra m m e.
4. IN D IR E C T boiler no t
w ork ing .
4 . C h ec k boiler op eration . If fau lt is
s us pec ted c on s ult bo iler m an ufac turer's
ins tru c tions .
5. IN D IR E C T th erm a l c ut-ou t
ha s op era te d.
5 . C h ec k . R e s e t b y pu s h in g bu tto n on c u t-
6. IN D IR E C T m oto ris e d va lve
no t c on ne c ted c orrec tly .
6 . C h ec k w iring a nd/o r p lu m bin g
c on nec tio ns to m otoris e d valve (s e e F ig 13
and 14).
7. SOLAR, Insufficient solar
gain with no auxiliary heating
switched.
7. Check auxiliary heat source is switched on and
is controlled to provide heat gain if no solar
output is available
1. INTERMITTENTLY
Air volume has reduced within
the expansion vessel
1. See Page 28 for details on how to test and
recharge
o ut. C h ec k op eration of ind ire c t
therm o s ta t (Figure 16, page 23 ).
2. C O N TIN U A L LY
W a ter dis c harg es from t h e
T&P Relief valve intermittently
W a ter dis c harg es from the
T&P Relief valve continually
a. 3 B a r P r e s s u r e R e d u c i n g
Valve not working correctly
2 a. C hec k pre s s ure from 3 Bar Presssure
Reducing Valve. If grea ter than 3 b ar
rep lac e P re s s ure R ed uc er c artridge .
b. E x p an s ion V alve s ea t
da m ag ed .
2 b. R em o ve E x p ans io n Relief c artrid ge from
8 Bar Pressure Relief valve and check seating. If
necessary fit new cartridge
1. Air volume in Megaflo eco has
reduced
1. S ee P a g e 3 8 ( O p e r a t i o n a l F a u l t s
s e c tio n for re-c h arging )
2. 8 Bar expansion relief valve
faulty
2. C h e c k v a l v e a n d r e p l a c e i f n e c e s s a r y
1. Th erm a l c ontro l failu re
N O TE w ater w ill b e ve ry ho t.
maintenance and
servicing (3)
W a ter dis c harg es from
E x pa ns io n V alve
3. IN D IR E C T prog ram m e r s et
to C en tra l H ea tin g on ly .
1 . S w itc h off pow e r to im m e rs ion h ea te r(s )
a nd s hu t d ow n b oile r. D O N O T turn o ff
w ate r s up ply . W h en d is c h arge s top s
c he c k a ll th erm a l c on tro ls , rep lac e if fa ulty .
M ilk y w ater
1. O x y ge na te d w ate r.
1 . W ate r from a p res s uris e d s y s tem
releases oxygen bubbles when
fl o w i n g . T h e m i l k i n e s s w i l l
dissappear after a short while
Unvented Hot Water Cylinder
29
Servicing
Important
i)Servicing should only be carried by authorised heateam engineers, Agents or by installers competent in the installation and maintenance of
unvented water heating systems.
ii)Any spare parts used MUST be authorised Megaflo eco Solar parts.
iii)Disconnect the electrical supply before removing any electrical equipment covers.
iv)NEVER bypass any thermal controls or operate system without the necessary safety valves.
v)Water contained in the Megaflo eco Solar unit may be very hot, especially following a thermal control failure. Caution must be taken when
drawing water from the unit.
Spares
maintenance and
servicing (3)
Spare parts
A full range of spare parts are available for the Megaflo eco Solar range. Refer to the Technical Data label on the unit to identify the model
installed and ensure the correct part is ordered.
30
Description Cold Water Inlet Control Kit - Complete
Part no.
95:605:894
3 Bar Pressure Reducing Valve - Complete
Strainer Mesh
3 Bar Pressure Reducing Valve Cartridge
95:605:886
95:605:889
95:695:891
8 Bar Pressure Relief Valve - Complete
8 Bar Expansion Relief Cartridge
8 Bar Pressure Relief Tee with Check Valve
Check Valve Cartridge
90:605:893
95:605:888
95:605:887
95:605:890
Stopcock 95:605:885
Immersion Heater Backnut
Immersion Heater Gasket
Immersion Heater Key
Immersion Heater Blanking Plug
Titanium Immersion Heater - Upper
Titanium Immersion Heater - Lower
Direct Combined Thermostat / Thermal Cut-Out
Tundish
95:607:940
95:611:822
95:607:861
95:605:881
95:606:989
95:606:988
95:612:717
95:605:838
Direct Titanium Control Cover
Mounting Plate (Direct)
3 way Terminal Block (Direct)
3 way Terminal Block (Solar) 95:614:119
95:607:929
95:607:932
95:607:939
Insulation Set ( T & P Relief Valve )
95:607:922
Indirect Accessory Kit (210L, 250L & 300L)
Mounting Plate (Indirect)
Indirect Control Cover
6 way Terminal Block
2 Port Motorised Valve (22mm Connections )
Incoloy Immersion Heater - Lower
Titanium Immersion Heater - Upper
Indirect Combined Thermostat and Cut-out
95:970:554
95:607:931
95:614:118
95:607:933
95:605:819
95:606:984
95:606:985
95:612:716
Temperature / Pressure Relief Valve
Set of Compression Nuts and Olives
Drain Valve 1/4 Turn
Mounting Plate, Solar
1/2”BSP Sensor Pocket Assembly Short
Twin Solar Temperature Pocket
Expansion Vessel (24 Litre)
Solar Thermal Cut-Out
95:605:810
95:607:838
95:605:051
95:607:937
95:607:938
95:606:990
95:607:612
95:612:698
Unvented Hot Water Cylinder
Figure 18 - Exploded View of 3 Bar Inlet Control Valve
Pressure Reducing
Valve Cartridge (3 Bar)
95:605:891
Strainer Mesh
95:605:889
3 Bar Pressure Reducing Valve - Complete
95:605:886
Figure 19 - Exploded View of 8 Bar Pressure Relief Valve
Expansion Relief Cartridge
95:605:888
Check Valve Cartridge
95:605:890
maintenance and
servicing (3)
8 Bar Pressure Relief Tee
with Check Valve
95:605:887
8 Bar Pressure Relief Valve, Complete
95:605:893
Stopcock, Can Be Used Either with
3 Bar Inlet Control Valve or 8 Bar
Pressure Relief Valve
95605885
Figure 20 - Exploded View of Stopcock
Unvented Hot Water Cylinder
31
Figure 21: Indirect Exploded View
1/2”BSP Sensor Pocket Assembly Short
95:607:938
B
C
B
C
A
A
Indirect Combined
Thermostat and
Thermal Cut-Out
95:612:716
maintenance and
servicing (3)
Terminal cover
95:614:118
Direct Combined
Thermostat and
Thermal Cut-Out
95:612:717
Mounting Plate (Indirect)
95:607:929
B
6 Way Terminal Block
95:607:933
Gasket
95:611:822
Backnut
95:607:940
Terminal cover
95:614:118
Incoloy Immersion
Heater, Lower
95:606:984
Mounting Plate (Solar)
95:607:937
Solar Thermal Cut-Out
95:612:698
A
Gasket
95:611:822
Backnut
95:607:940
32
Unvented Hot Water Cylinder
Twin Solar Temperature
Probe Pocket Plate
95:606:990
3 Way Terminal Block
95:607:939
Figure22: Direct Exploded View
D
C
1/2”BSP Sensor Pocket Assembly Short
95:607:938
B
D
A
Mounting Plate (Direct)
95:607:929
Direct Combined
Thermostat and
Thermal Cut-Out
95:612:717
C
Terminal cover
95:614:119
Terminal cover
95:614:119
Backnut
95:607:940
Three Way Terminal Block
95:607:932
Gasket
95:611:822
Mounting Plate (Direct)
95:607:929
Backnut
95:607:940
Direct Combined
Thermostat and
Thermal Cut-Out
95:612:717
maintenance and
servicing (3)
Titanium Immersion
Heater (Upper)
95:606:989
Gasket
95:611:822
B
Titanium Immersion
Heater (Lower)
Three Way Terminal Block
95:606:988
95:607:932
A
See Figure 21 for Solar Control parts (page 32)
Unvented Hot Water Cylinder
33
maintenance and
servicing (3)
34
Unvented Hot Water Cylinder
maintenance and
servicing (3)
Unvented Hot Water Cylinder
35
Spares Stockists
Electric Water Heating Co.
2 Horsecroft Place
Pinnacles
Harlow
Essex
CM19 5BT
Tel: 0845 0553811
E-Mail: sales@ewh.co.uk
SPD
Special Product Division
Units 9 & 10
Hexagon Business Centre
Springfield Road
Hayes
Middlesex
UB40 0TY
Tel: 0208 5730574
Parts Center
Network 65 Business Park
Bentley Wood Way
Burnley
Lancashire
BB11 5ST
Tel: 01282 834403
www.partscenter.co.uk
Newey & Eyre
Specialist Products Division
Please Contact your Local Branch
user guide (4)
UK Spares Ltd
Tower Lane
Warmley
Bristol
BS30 8XT
Tel:0117 961 6670
36
William Wilson Ltd
Unit 3A
780 South Street
Whiteinch
Glasgow
G14 0SY
Tel: 0141 434 1530
Unvented Hot Water Cylinder
user guide (4)
• User Instructions
• Guarantee
• Customer Service
Unvented Hot Water Cylinder
37
IMPORTANT LEGAL REQUIREMENT FOR INSTALLERS
Megaflo eco Solar, a trading name of Heatrae Sadia Heating, a licensed member of the BenchmarkTM Scheme which
aims to improve the standards of installation and commissioning of domestic heating and hot water systems in the
UK and to encourage regular servicing to optimise safety, efficiency and performance. is managed and promoted by
the Heating and Hotwater Industry Council. For more information visit www.centralheating.co.uk. Please ensure that
the installer has fully completed the Checklist on Page 34 of this manual 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 Checklist. This product should be serviced regularly to optimise its safety, efficiency and performance.
The service engineer should complete the relevant Service Record on the Checklist after each service. The Checklist
may be required in the event of any warranty work.
User Instructions
Warnings
IF WATER DISCHARGES FROM THE TEMPERATURE / PRESSURE RELIEF VALVE ON THE MEGAFLO ECO SOLAR UNIT REFER
TO PAGE 29 (TABLE 6) FIRST FOR GUIDANCE. IF THIS DOES NOT RECTIFY THE FAULT SWITCH OFF ELECTRICAL SUPPLY TO
THE IMMERSION HEATER(S) [ DIRECT UNITS ] OR SHUT DOWN THE BOILER [ INDIRECT UNITS ]. DO NOT TURN OFF THE
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 MEGAFLO ECO SOLAR SYSTEM, IF A FAULT IS
SUSPECTED CONTACT A COMPETENT INSTALLER.
SOLAR PRIMARY CIRCUIT
Temperature control when heating by the solar primary circuit will be controlled by the external solar differential temperature
controller. The controller should be set to give a water storage temperature of approx. 60oC, however it can be set to other
temperatures. This will usually have been done during installation. A maximum of 70oC is recommended to avoid nuisance
operation of the thermal cut-outs fitted to the unit. Adjustment is made at the solar differential temperature controller, refer to the
manufacturer’s instructions for details of how to make any adjustments.
Changes to the operating temperature differential set points can affect the efficiency of the operation of the solar heating circuit, it is
recommended that any changes made are carried out by a competent solar water heating installation engineer.
Immersion Heaters
A combined thermostat and thermal cut-out is provided for each immersion heater. The thermostat is factory set to give a water
storage temperature of approx. 60ºC, however it can be set to control between 12ºC and 68ºC. This will usually have been done
during installation. Adjustments can only be made by opening the terminal cover(s), DO NOT remove the cover(s) without first
switching off the electrical supply. The temperature adjustment is made by inserting a flat bladed screwdriver in the slot in the
disc on top of the thermostat and rotating (see Figure 16, page 23).
If in any doubt consult a competent electrician.
Indirect units (CL models) are fitted with an Indirect Thermostat which controls a 2-port motorised valve and hence the temperature
of the water in the Megaflo eco Solar unit. The thermostat is factory set to give a water storage temperature of approx. 60ºC,
however it can be set to control between 12ºC and 68ºC, this will usually have been done during installation. Adjustments can only
be made by opening the terminal cover. DO NOT REMOVE THE COVER WITHOUT FIRST SWITCHING OFF THE ELECTRICAL
SUPPLY. Temperature adjustment is made by inserting a flat bladed screwdriver in the adjustment knob located on the front of the
thermostat mounting bracket (see Figure 16, page 23 ) and rotating. At the minimum position the temperature will be approx. 12ºC.
If in any doubt consult a competent electrician.
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 and does not indicate a fault. In some areas a 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
user guide (4)
Operational faults and their possible causes are detailed in Table 6, page 29 . It is recommended that faults should be checked by a
competent installer.
The air volume within the expansion vessel will periodically require re-charging to ensure expanded water is accommodated within
the hot water system. A discharge of water INTERMITTENTLY from the Expansion Valve will indicate the air volume in the Expansion
Vessel has reduced to a point where it can no longer accommodate the water expansion.
If after following the above actions water still discharges from the Expansion Relief Valve further advice should be sought from a
competent installer or the heateam service department.
38
Unvented Hot Water Cylinder
Lifetime Guarantee Terms and Conditions
WARNING: Should the factory fitted temperature and pressure relief valve be tampered with or removed your guarantee will be
invalidated. Neither the Distributor nor Manufacturer shall be responsible for any consequential damage howsoever caused.
Guarantee Terms
Heatrae Sadia guarantees the Megaflo eco Solar against faulty manufacture or materials for a period of two years from the date
of purchase including parts and labour. This two year guarantee is extended to five years for the cold water control valve and to
lifetime* for the stainless steel inner vessel in domestic properties and to 30 years for the stainless steel inner vessel in commercial
buildings.
These guarantees are valid provided that:
The Megaflo eco Solar has been installed by a competent installer and as per the instructions contained in the installation manual and all relevant
Codes of Practice and Regulations in force at the time of installation.
Any disinfection has been carried out in accordance with BS 6700.
The Megaflo eco Solar has not been modified in any way other than by heateam approved engineers.
The Megaflo eco Solar has only been used for the storage of wholesome water (max. 250mg/l chloride).
The Megaflo eco Solar has not been subjected to frost, nor has it been tampered with or been subjected to misuse or neglect.
No factory fitted parts have been removed for unauthorised repair or replacement.
The BenchmarkTM Commissioning Checklist and Service Record included in this product Guide has been completed.
Regular maintenance has been carried out by a competent person in accordance with the requirements set out in the maintenance section of the
installation manual and any replacement parts used should be authorised Heatrae Sadia Megaflo spare parts. Annual Services are available from
heateam, the service division of Heatrae Sadia. Please contact heateam on Tel: 0844 871 1535 for further details.
Within 60 days of purchase the owner completes and returns the certificate supplied to register the product. Evidence of purchase and date of
supply must be submitted upon making a claim.
This guarantee is not valid for installations outside the United Kingdom.
For installations outside of the United Kingdom, please contact either the Megaflo Export Department on Tel: +44 1603 420271 or Baxi
International on Tel: +44 1926 478323 for further details of the guarantee terms and conditions applicable. This guarantee does not affect your
statutory rights.
The unit is not guaranteed against damage due to frost. This guarantee does not affect your statutory rights.
*Lifetime is defined as for as long as the original owner who purchased the Megaflo eco Solar / New Home continues to own the
property. If the owner sells the property, the new owner (and any future owners) will receive a 30 year warranty from the time the
original owner purchased the Megaflo eco Solar or new property with Megaflo eco Solar installed.
user guide (4)
Unvented Hot Water Cylinder
39
Customer service
Telephone:
0844 8711535
Facsimile:
0844 8711528
E-mail:
megafloservice@heateam.co.uk
Megaflo
Hurricane Way
Norwich
Norfolk
NR6 6EA
© 2010
36006063_issue_04