Fabdec EXCELSIOR User manual

Water heating systems
March 2014
Installation Manual
EXCELSIOR Unvented Water Heater
EXCELSIOR®

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Contents
Section: Title: Page:
1 Introduction 3
1.1 Specifier’s Guide 3
1.2 Standard Equipment 4
2 Dimensions & Performance 4
2.1 Excelsior Direct & Indirect Internal 5
2.2 Excelsior Direct & Indirect External 6
2.3 Excelsior Solar Range 7
2.4 Excelsior Heat Pump Range 8
2.5 Excelsior Buffer Range 9
2.6 Excelsior Horizontal Direct Range 9
2.7 Excelsior Horizontal Indirect Range 10
3 Installation Instructions 11
3.1 Installation Requirements 11 -13
3.2 Recommended Installation Schematics 14 - 15
3.3 Wiring Instructions 16 - 18
3.4 Tundish 18
3.5 Discharge Pipework 19 - 20
3.6 Commissioning 21
4 Warranty 22
5 Servicing & Maintenance 23
6 Fault Finding 24
7 Spare Parts 25
8 Disposal 25
9 Commissioning Checklist 26
10 Service Record 27
11 Contact Information Rear cover

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1. Introduction
The Excelsior unvented water heater is a high quality stainless steel unvented cylinder which can provide hot water from a
cold mains water supply of between 1.5 bar and 16 bar.
The indirect heat exchanger surfaces are designed to provide a rapid heat up time. The unit comes complete with all the
necessary safety equipment to comply with legislation governing the installation of such systems.
The Excelsior Solar and Heat Pump unvented water heaters have been designed for use with all solar panels and ground
or air source heat pump systems requiring a storage and heating vessel (please ensure compatibility prior to installation)."
1.1 Specifier’s Guide
The Law & Unvented
It is legal to fit an unvented unit into any property."
There is no longer a requirement to have an old-fashioned ‘Tank in the Roof’ system.
The Benefits of Excelsior
Duplex stainless steel
High quality finish
Low heat loss for maximum economy
No sacrificial anode - low maintenance
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The Benefits of Unvented Systems
The Excelsior fills a bath in minutes and can run two at the same time
The Excelsior can work off electricity (Economy 7) or alternative energy systems*
A power shower without the noisy pump
No tanks in the roof
No ball cocks to jam or leak
All your water, hot and cold, direct from the mains
Site the Excelsior unvented water heater wherever convenient*
*not suitable for solid fuel boilers. *refer to ‘Siting the Excelsior unit’ in section 3.1
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Excelsior Solar
The Excelsior solar range is available in many vessel capacities, in both direct (electric) or indirect models. Each cylinder
has been specifically designed for use with an alternative energy heating system and includes a large corrugated coil heat
exchanger that provides optimum heat transfer from the alternative heat source to the water in the cylinder.
The Excelsior solar unvented water heater should only be used as part of a solar installation and configured as shown.
Additional safety devices may be required if the cylinder is operated with other heat sources.
Excelsior Heat Pump
The Excelsior Heat Pump range has been specifically designed to optimise the output from the heat pump. It is fitted with
a corrugated coil heat exchanger that has a larger diameter than that used on the standard Excelsior cylinders.
Always ensure the correct type of cylinder is paired with the renewable heat source. Failure to do this may result
in the system being inefficient and in extreme cases cause failure of components. Consult the heat pump/solar
installation manual prior to cylinder installation.

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1.2 Standard Equipment
Check that all the components of your Excelsior unit are contained in the kit prior to installation.
Your Excelsior should include the following:
3kW heating element - incorporating control thermostat and re-settable safety cut-out
Combination (control) valve comprising:
Line strainer, non-return (check) valve, pressure reducing valve & expansion relief valve
Tundish - 15mm female x 22mm female
Temperature/Pressure relief valve - set at 90°C and 7 bar pressure (factory fitted)
Cylinder thermostat - temperature control setting 30-70°C (indirect units only)
Thermal cut-out - set to operate at 82°C +/-5°C (indirect units only)
Expansion vessel - with capacity to suit vessel size (external expansion units only)
Motorised valve (indirect units only)
2. Dimensions and Performance
The diagrams on the following pages show the standard range of Excelsior vessels.
All dimensions are in millimeters unless otherwise stated. (Tolerance +/- 10mm)
All unvented installations must comply with local building regulations.
England & Wales: G3 Building Regulations
Scotland: Technical Standard P3
Northern Ireland: Building Regulation P5"
Excelsior coil data is based on a max primary flow temperature of 80°C.
Water flow and return temperature differential of 20°C.
It is recommended that the back pressure in the coil is restricted to 0.3bar. (See table below for flow rates)
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Note: The vessel working volume is the gross volume minus the displaced volume of any coil heat exchanger or
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2.1 Excelsior Direct and Indirect Cylinders-Internal

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2.2 Excelsior Direct and Indirect Cylinders-External

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2.3 Excelsior Solar Range

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2.4 Excelsior Heat Pump Range

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2.5 Excelsior Buffer Range
2.6 Excelsior Horizontal Direct Range

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2.7 Excelsior Horizontal Indirect Range

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3. Installation Instructions
3.1 Installation Requirements
WARNING: UNDER NO CIRCUMSTANCES MUST THE FACTORY FITTED TEMPERATURE PRESSURE RELIEF VALVE BE
REMOVED. THIS WILL INVALIDATE ANY GUARANTEE OR CLAIM. THE COLD-WATER INLET VALVE ASSEMBLY MUST BE
FITTED OR THE EXCELSIOR UNIT WILL NOT PERFORM SATISFACTORILY.
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DO NOT ATTEMPT TO VENT THE PRIMARY CIRCUIT THROUGH THE EXCELSIOR UNIT."
ALL EXTERNAL HEAT SOURCES SHOULD BE INSTALLED TO MANUFACTURERS INSTRUCTIONS AND THE PRIMARY CIRCUIT
THROUGH THE EXCELSIOR UNIT MUST BE PUMPED.
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Benchmark Scheme Checklist"
Benchmark 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. The Benchmark Code of Practice is available from the Heating and Hot
Water Industry Council, who manage and promote the scheme.Visit www.centralheating.co.uk for more information.
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Please ensure that the installer has fully completed the Benchmark Checklist on the inside back pages of the installation
instructions supplied with the product 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).
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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 Benchmark Checklist.
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Siting the Excelsior unit
Note: Excelsior cylinders are designed for indoor use only
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The unit can be placed anywhere convenient. Since it is connected directly to the mains water supply it is equally efficient
on any floor – ground, first or second. Avoid areas that may be subject to frost.Try to keep pipe runs as short as possible
for maximum economy, especially hot water discharge pipes running down from the Excelsior unit."
The unit can be fitted into a conventional airing cupboard and does not require any additional insulation.
The water supply to the cylinder should be potable water direct from a public mains supply with any water treatment
equipment functioning correctly.
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Vertical cylinders
If installing a vertical cylinder, ensure it is fixed securely in an upright position for correct operation.
Horizontal cylinders
If installing a horizontal cylinder, ensure it is fixed securely with the temperature and pressure relief valve positioned at the
top for correct operation.
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Storage & Handling"
If the cylinder is not being installed immediately, it should remain in its protective wrapping with all pipe end protective
caps in place to prevent damage.
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Connecting the Water Supply"
Pipework is not supplied."
All pipework should be installed using good plumbing practice. We recommend 22mm mains cold water supply is used."
Install a stop cock valve before the cold water inlet assembly on the incoming mains water supply so the unit can be
isolated if required.

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Cold Water Valve"
The combined cold water valve (supplied) can be connected anywhere on the cold water mains prior to the unit. It can be
located at a point near to where the mains supply enters the premises if this is more convenient. When installing the cold
water valve, ensure that the arrow is pointing in the same direction as the mains water supply flow when connecting (see
figures 5 and 6). "
The cold water balancing port, on the valve, allows you to connect the cold water mains to the rest of the property thus
giving balanced pressure throughout.If this facility is not required leave the cap on.
Check Water Pressure & Flow Rates
Fabdec suggests 1.5 bar pressure & 20 litres/minute flow rate to be the minimum requirements for satisfactory operation.
The unit will still operate below this, but it will not be possible to run two or more outlets at the same time.
The mains supply must not exceed 3 bar. If it does a special pressure-reducing valve will be required.
Consideration should be given to the routing of the discharge pipe and the location of the solar panel or alternative energy
source where applicable.
Drain Tap
A drain tap to drain the unit must be fitted to the cold-water inlet pipe between the Excelsior cylinder and the cold water
valve assembly at its lowest level possible (see figures 2, 3 and 5).
Pipework to Taps
Ideally a 22mm pipe should supply the outlets throughout the property with short lengths (max 1 metre) runs of 15mm
going to baths, showers, and basin taps. Smaller bore pipe can be used to suit taps.
Taps & Fittings
All taps and fittings incorporated into the unvented system should have a rated operating pressure of 7 bar or above.
Inlet Group
The inlet group will vary depending on whether the vessel is fitted as internal or external expansion (see figures 2, 3, 5
and 6).
Primary Circuit
The motorised valve supplied and the thermal cut-out (high limit stat) must be fitted to the primary flow (Use compression
fittings only).
Operation of the cut-out & motorised valve
To comply with regulations and to prevent the temperature reaching 100°C the thermal cut-out supplied must be fitted.
The thermal cut-out is wired in series to the cylinder thermostat. When the thermal cut-out senses an abnormal rise in
temperature in the primary flow the electrical supply to the motorised valve will be cut and the valve will return to the
closed position. This will cut-off the primary water from the boiler to the indirect coil in the cylinder.
If the thermal cut-out operates it must be reset manually. Check the cylinder stat and/or boiler stat.
Primary Circuit (Excelsior Solar)
Excelsior solar cylinders are suitable for connecting to a solar collector system and, where a twin coil is present (indirect)
to a gas or oil central heating boiler.
WARNING: SOLID FUEL OR WOOD BURNING BOILERS AND GRAVITY CIRCULATION SYSTEMS MUST NOT
BE USED ON THE PRIMARY CIRCUIT OF AN UNVENTED HOT WATER SYSTEM.
The cylinder should be installed in accordance with the solar installation instructions for connection to the primary flow and
return.
The Excelsior Solar range must only be connected to solar installations containing a hydraulic station with two non-return
valves (one in the flow to the collector and one in the return). This will prevent thermal siphoning of the heat transfer fluid
when the pump is switched off.
Where two non-return valves are not present or a hydraulic station is not used in the solar system, a second two-port valve
must be installed into the flow of the solar coil and wired to the lower two-port valve.
The Excelsior Solar is supplied with one two-port motorised valve which should be connected in the flow to the auxiliary
coil and wired to the upper twin thermostat of the cylinder.
Solar pump: The lower twin thermostat should be connected in line with the solar pump power supply.
The factory fitted temperature and pressure relief valve should not be removed from the cylinder or tampered
with in any way. The valve is pre-calibrated to open at 7 bar or 90°C and any attempt to adjust it will invalidate the
warranty and could affect the safety performance of the unit.

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Secondary Return (where applicable)
Some Excelsior cylinders are fitted with a secondary return connection. Secondary circuit connections must be made to
the cylinder in accordance with the recommended installation diagram. A drain cock (not supplied) should be fitted in the
cold water inlet to facilitate draining of the cylinder (see Figure 1). A swept tee* is needed for all indirect models if
secondary circulation is required and is fitted as per the illustration. A non-return valve* must also be fitted to prevent
backflow. A pump* will be required to circulate the hot water. The return feed is in 15mm pipe and all work can be done on
site. *not supplied
IMPORTANT: IF A SECONDARY CIRCULATION CIRCUIT IS INSTALLED THEN A LARGER EXPANSION VESSEL
MAY BE REQUIRED TO HANDLE THE INCREASE IN WATER VOLUME. CALCULATE THE ADDITIONAL WATER
VOLUME AND CONTACT OUR CUSTOMER SERVICES DEPARTMENT REGARDING SUITABLE VESSEL SIZES.
Figure 1. Secondary Return
External Expansion Vessel (where applicable)
This smaller tank is connected to the cold-water inlet side of the vessel. Mount the tank according to separate
manufacturer’s instructions provided with the external expansion vessel.
A suitable expansion vessel with a pre-charge pressure of 3.5 bar is supplied with Excelsior cylinders with external
expansion.
The expansion vessel should be Tee’d off between the pressure relief valve and the cylinder (see figure 2) and should
always be positioned with the entry point at the bottom. Installation should always be by means of a standard T connector
ensuring no other valve is between this and the cylinder. Adjust the pressure to 3.0 - 3.5 bar.

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3.2 Recommended Installation Schematics
Figure 2. Installation Schematic – External Expansion
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Figure 3. Installation Schematic – Internal Expansion
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Figure 4. Combination Valve
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Figure 5. Inlet Group – External Expansion"
Figure 6. Inlet Group – Internal Expansion"
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3.3 Wiring Instructions"
WARNING: ALL ELECTRICAL WIRING SHOULD BE CARRIED OUT BY A COMPETENT ELECTRICAL
CONTRACTOR AND MUST CONFORM TO THE LATEST IEE WIRING REGULATIONS. DO NOT SWITCH THE
POWER ON UNTIL THE UNIT HAS BEEN FILLED WITH WATER AND ALL WIRING HAS BEEN EARTHED. "
(SEE FIGURES 7, 8, 9 & 10)
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Figure 7. S Plan Wiring Diagram
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Figure 8. Y Plan Wiring Diagram

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Fitting the immersion heaters
The heating element is fitted with a control thermostat which allows the water temperature to be set and a thermal cut-out
for safety (see Figure 9). The unit is designed to screw into the 1!" boss fitted to the unit. An ‘O’ ring is supplied as the
seal and must be fitted against the flange of the element. Take care not to cross thread and DO NOT use any other
type of seal.
Replacement elements can be obtained through your authorised service agent.
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Immersion Heater (Excelsior Solar)"
Secondary circuit connections MUST be made to the cylinder in accordance with the recommended installation diagram. A
drain cock* should be fitted in the cold water inlet to facilitate draining of the cylinder. * Not supplied.
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IMPORTANT: ENSURE THAT THE IMMERSION HEATER THERMOSTAT IS SET TO A MAXIMUM OF 60°C."
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Figure 9. Immersion Heater Connections and Control Thermostat Settings
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Fitting the twin thermostat
Figure 10. Cylinder Thermostat & Thermal Cut-out Connections
(Refer to wiring diagrams for correct installations)

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Two Port Valve
The two port valve should be wired to the thermostat (see Figure 7 or 8 depending on required configuration). Connect the
live supply to the thermo cut-out and connect the brown wire of the two port valve to terminal 1on the thermostat (see
Figure 11). Earth and Neutral supplies can be connected directly to the valve. The orange wire of the two port valve should
be connected to the central heating boiler and the cylinder thermostat set to 60°C. The power supply to the pump station
should be connected via the lower valve
Figure 11. Twin thermostat wiring
3.4 Tundish
The tundish supplied must be fitted so it is visible to the occupier. The discharge pipe must be 22mm copper pipe.
Regulations do not permit more than 3 x 90-degree bends between the Excelsior unit and the outflow. Between the
temperature & pressure relief valve and the first 90-degree bend there must be a fall of at least 300mm. The fall of the
pipework must be continuous and the pipe should terminate in the gully or be bent backwards onto an outside wall, in a
place where discharge cannot be injurious to persons.
If you need to site the Excelsior unit in the middle of the house your discharge pipe to the tundish can be as far away as
9m, which in most cases is enough to run the final discharge point. After 9m, increase the pipe size to a greater diameter
than 22mm and accordingly for subsequent 9m lengths, (see table 1).
Figure 12. Tundish Installation
IMPORTANT: REGULAR CHECKS SHOULD BE CARRIED OUT TO ENSURE THAT THE EXPANSION VESSEL IS ALWAYS
CORRECTLY PRESSURISED TO 3.5 BAR.

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3.5 Discharge Pipework#
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.’
G3 Guidance Section 3.5
The discharge pipe (D1) from the vessel up to and including tundish is generally supplied by the manufacturer of the hot
water storage system. Where otherwise the installation should include the discharge pipe(s) (D1) from the safety
device(s). In either case 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 safety device, with no more than 600mm of pipe between
the valve outlet and the tundish (See Figure 13).
The discharge pipe (D2)
The discharge pipe (D2) from the tundish should:
Have a vertical section of pipe at least 300mm long below the tundish before any elbows or bends in the pipework (see
Figure13).
Be installed with a continuous fall of at least 1 in 200 thereafter.
The discharge pipe (D2) should be made of metal or 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 7291-1:2006 Thermostatic pipes and fittings for hot and
cold water for domestic purposes and heating installations in buildings, General Requirements).
Termination of discharge pipe
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.
Examples of acceptable discharge arrangements are:
To a trapped gully with the end of the pipe below a fixed grating and above the water seal.
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.
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.
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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
The example below is for 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 1: (overleaf)
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Maximum resistance allowed for a straight length of 22mm copper discharge pipe (D2) from G1/2 temperature relief valve
is 9m. Subtract the resistance for 4 No 22mm elbows at 0.8m each = 3.2m, therefore the permitted length equates to
5.8m. This is less than the actual length of 7m therefore calculate the next largest size.
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Maximum resistance allowed for a straight length of 28mm pipe (D2) from a G1/2 temperature relief valve equates to 18m
Subtract the resistance of 4 No 28mm elbows at 1m each = 4m.
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Therefore the maximum permitted length equates to 14m. As the actual length is 7m a 28mm (D2) copper pipe will be
satisfactory.
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Figure 13. Typical discharge pipe arrangement"
IMPORTANT: THE DISCHARGE WILL CONSIST OF SCALDING WATER AND STEAM. ASPHALT, ROOFING FELT AND NON-
METALLIC RAINWATER GOODS MAY BE DAMAGED BY SUCH DISCHARGES.
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Table 1.Sizing of copper discharge pipe (D2) for common temperature & pressure relief valve sizes
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