ESP Ecocent 200L User manual

ESP ECOCENT 200&300L
Installation and Operation Manual

WARNING !
READ THIS BEFORE INSTALLING THE
UNIT.
All un-vented water heating systems above 15 litres (this includes the ESP Ecocent Hot water ASHPs)
MUST be installed to meet the requirements of the local area Building Regulations. It is a legal
requirement that the local Building Control Officer be notified of any proposed installation of un-vented
water heating systems over15 litre capacity.
Furthermore, it must be fitted by an installer who has successfully completed a recognised course in the
installation of un-vented heating systems such as CITB and be familiar with installing the Ecocent unit.
Failure to properly fit the unit may affect its safety, efficiency and invalidate any guarantee.
Safety requirements in the UK call for an expansion space (internal or external),safety devices to prevent
the stored water exceeding 100°C, and pipe work to convey discharged hot water safely away from the
safety devices.
THE UNIT MUST BE INSTALLED, COMMISSIONED AND MAINTAINED 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 UNIT SHOULD BE
EXPLAINED TO THE USER AND THESE INSTRUCTIONS LEFT WITH THEM FOR FUTURE REFERENCE.

Contents
1.0 Preface
2.0 General Notes
2.1 Safety Precaution Notes
2.2 Installation Notes
2.3 Operating Notes
2.4 Notes on Moving and Repairing the Unit
2.5 Operation Notes
2.6 General Requirements
3.0 Component Checklist
4.0 Positioning the Unit
4.1 Some notes on Ducting
4.2 Water Supply
4.3 Outlet/Terminal fittings (Taps etc.)
4.4 Limitations
4.5 Hot Water ASHP Package
4.6 Basic system schematic
5.0 Specification
5.1 Appearance
5.2 Dimensions
5.3 Performance
5.3.1 Performance assumptions
5.4 DHW Recovery Times
6.0 Installation
6.1 Installation Diagram
6.2 Indirect Thermal cut-out (dual stat) and 2-Port Motorised Valve
6.3 Pipe fittings
6.4 Cold Water Supply
6.5 Cold Water Combination Valve
6.6 Drain-Off Cock
6.7 Outlet Pipe Work
6.8 Secondary Circulation of DHW
6.9 TPRV
6.10 Warnings
6.11 Discharge Pipe Work
6.12 Expansion Vessel
6.13 G3 Requirement
6.14 G3 Guidance Section
7.0 How to connect to the Heat Pump
7.1 Vacuum and filling refrigerants
7.2 Controller System Test
7.3 Preparing for refrigerants
7.4 Insulation Treatment
7.5 Wiring
7.6 Earthing
7.7 Unit System Controls
7.8 Immersion Heater

8.0 Operation
8.1 Control panel explanation
8.2 Display Explanation
8.3 Using the Control Panel
8.3.1 Before running the unit
8.3.2 Mode Selection
8.3.3 Setting the Clock
8.3.4 Setting the timers
8.3.5 Vacation Mode
8.3.6 Electric Heating Mode
8.3.7 Fan Mode Settings
8.3.8 Locking the keyboard
8.3.9 Parameters
9.0 Maintenance Requirements
9.1 Checking the operation of safety valves
9.2 Cleaning the Strainer
9.3 Draining the Unit
9.4 Descaling the immersion heater
9.5 Refilling the system
9.6 Log Book
9.7 Maintenance Requirements
10.0 Faults
10.1 Simple Fault Finding
11.0 Warranty
11.1 Guarantee Terms
12.0 Environmental Information
13.0 Spare Parts
13.1 Exploded View
Appendix 1. PCB Layouts.

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ESP400-10-200L and 300L
1.0 Preface:
This manual includes the necessary information about installation and maintenance of the Ecocent. Please read
this manual carefully before you install or carry out maintenance on the unit.
When installing the unit, please carry out the work strictly in accordance with the manual, relevant Regulations
and good practice.
Please do not switch the unit on until you are sure that it has been properly installed, electrically, mechanically,
hydraulically and that there is water in the system.
The installer should explain to the end user how to operate and maintain the unit before handing over the unit to
the end user. Also, the installer should advise the end user to read the manual fully before operating the unit and
leave this manual with end user.
Further, improper installation, operation and/or maintenance, and failure to maintain the unit as per this manual
will invalidate any unit warranty or guarantee.
The manual may be altered and/or updated in any way at the sole discretion of the supplier and/or ESP without
notice.
2.0 General Notes:
2.1 Safety Precaution notes
Below you will find information that is critical for the safe and proper installation and the use of the unit. Please
make sure that you understand the contents to help avoid the risk of injury or damage to the unit/other property.
2.2 Installation Notes:
Professional
&qualified
installer
is required
The heat pump must only be installed by asuitably qualified
engineer. Failure to ensure this can cause damage to the
unit and may cause serious injury. The warranty on the unit
will also be invalidated if asuitably qualified engineer is not
engaged to install it.
Earthing
required
Please make sure that the unit and power supply are
soundly earthed.
Refrigerant
If you are installing the unit in asmall room, please give full
consideration to adequate ventilation being available in the
event of arefrigerant leak.
Installation
Site
Do not install the unit near to agas installation. This unit is
designed to be installed inside abuilding.
Site
consideration
Ensure that this unit is installed on asolid level floor. Make
sure that you have asuitable facility to cater for disposal of
condensate from the condensate drain on the unit.
Circuit
Breaker
Make sure that this unit is connected to the power supply via
afused switched spur and suitably sized MCB for the
domestic ring main.
Unit Upright
The unit must be installed level across the whole diameter.
Failure to install the unit level will mean that condensate can
spill over the lip of the cylinder.

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ESP400-10-200L and 300L
2.3 Operating Notes:
2.4 Notes on Moving and Repairing the Unit:
Caution
This unit has ahigh centre of gravity. This unit must be
strapped to prevent it falling over when in transit.
Suitably
qualified
engineer
When moving the unit or carrying out repair work please be
sure to use only asuitably qualified engineer.
Do NOT
Do NOT try to install, move or repair the unit yourself –it is
NOT worthwhile running the risk of injury.
Transporting
the Unit
The unit must be transported in the vertical position. It can
be tilted up to 60° from the horizontal axis.
2.5 Operation Notes:
2.6 General Requirements:
IMPORTANT: PLEASE READ AND UNDERSTAND THESE INSTRUCTIONS BEFORE INSTALLING
THE ESP Ecocent (“DHW ASHP” or “unit”). INCORRECT INSTALLATION WILL INVALIDATE ANY
GUARANTEE.
PLEASE NOTE THAT THERE ARE ESSENTIALLY 2 UNITS COMBINED INTO ONE IN THE ESP
ECOCENT AND YOU MUST BE SURE TO UNDERSTAND BOTH ELEMENTS - THE INDIRECT HOT
WATER CYLINDER AND THE AIR SOURCE HEAT PUMP. PLEASE ALSO NOTE THE ECOCENT
CAN BE INSTALLED IN EITHER A VENTED OR UNVENTED SYSTEM.
3.0 Component Checklist:
Before commencing installation of the unit, check that all the components for your unit are contained in the
package. The following components are supplied as standard with any unit being installed in a
“mains pressure” configuration:
• Factory fitted immersion heater (s) and thermal controls.
• Cold Water Combination Valve (comprises Pressure Reducing Valve, Strainer, and Check Valve).
• Expansion Core Unit (comprises Check Valve and Expansion Valve).
• Temperature/Pressure Relief Valve (set at 90 - 95°C/1 Mpa (7bar).
• Tundish (included in Cold Water Combination Valve pack).
Do NOT
Do not push anything into the fan blades when running and
make sure that children cannot access the unit or play close
to the unit.
Shut off the
power
supply
If there is an unusual sound or smell coming from the unit,
immediately shut off the power supply and call your
installation engineer.
Siting the
Unit
The unit must only be installed indoors –the unit is neither
designed for, nor suitable for, installation outside. The Unit
needs to be sited where the ambient temperature never
goes below 5degrees. If the unit is to be left unused for any
significant period of time during which the ambient
temperature could cause the unit or pipe work from the unit
to freeze, it should be drained down.
Shut off the
power
When cleaning the unit, shut off the power supply.
You MUST
You must use asuitable power supply that is appropriately
fused.

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ESP400-10-200L and 300L
• Factory fitted Indirect Thermostat and Thermal Cut-out.
4.0 Positioning The Unit:
The unit must be vertically floor mounted. It can be placed anywhere convenient provided that the discharge
pipe(s) from its safety valves and air handling duct work can be correctly installed. Areas that are subject to
freezing must be avoided. Ensure that the floor is of sufficient strength to support the weight of the unit
when full with water. Pipe run lengths should be kept as short as possible for maximum economy and
efficiency: the use of secondary returns should be avoided. Access to associated controls, immersion heaters and
indirect controls must be possible for servicing and maintenance of the unit. Please do not install valves or pipe
work (except a discharge pipe) within 50mm (2”) of the T&P relief valve to allow insulation to be fitted. The
insulation is important to avoid heat loss.
Consideration must be given to the use of insulated ducting to carry air to and from the unit. Insulated ducting
must be used where condensate may form on the duct work.
IMPORTANT NOTE: DO NOT SITE THE UNIT IN THE SAME ROOM AS AN OPEN FLUED
APPLIANCE OR A ROOM WHERE AN OPEN FLUED APPLIANCE TAKES ITS COMBUSTION AIR
FROM, UNLESS THE MATTER HAS BEEN CAREFULLY CONSIDERED AND ADEQUATE
DUCTING AND VENTILATION HAS BEEN PROVIDED FOR THE UNIT (THE DHW ASHP) AND THAT
THE OPEN FLUED APPLIANCE IS FULLY CATERED FOR IN TERMS OF A SUITABLE AIR SUPPLY.
Please be sure to use appropriate lifting equipment when moving the unit.
Some things to be considered when positioning the unit:
Waste heat is useful heat.
The Ecocent works by harvesting ‘waste’ heat from areas where there is a build up of unwanted heat.
Traditionally, moist, warm air is expelled from building by mechanical means or by opening windows. The
Ecocent uses this waste heat to heat hot water. Air can be ducted from areas such as Bathrooms, Kitchen and, in
a commercial environment, Server Rooms to the Ecocent via 150mm insulated ducting. In a domestic
environment, this could include areas of high solar gain. The resultant cold, dry air is ejected from the building
via more insulated 150mm ducting. Alternatively, the Ecocent can be installed in areas where there is a build
up of heat negating the need for input ducting and the cold air can then be vented outside the building via
ducting.
Always be sure to site the unit and arrange the duct work to maximise the use of available waste heat. This will
allow the Ecocent to operate at maximum efficiently.
The secondary coils in the Ecocent enable direct connection to a second stable heat source, e.g. a solar heating
system or a boiler. Under no circumstances is the Ecocent to be installed onto an uncontrolled heat source e.g.
wood burner or back boiler.
Dehumidification – The Ecocent can be used to dehumidify rooms that are hot and damp – e.g. Laundry rooms
etc. The unit is equipped with a condensate drain that must be properly directed to a suitable waste pipe where
the condensate water (non acidic) can drain away. If the drain is into a main sewer it must have a trap installed
to prevent back smell through the Ecocent.
Directional Cooling – ducting can be fitted with air diverters (e.g the ESP “Ecobox”) so that cool exhaust air
from the Ecocent can be directed to chosen areas such as server rooms for commercial applications.
Positioning the Ecocent – some further points:
1. Decide upon the right route to be taken to move the unit in to the chosen position.
2. Try to move the unit in its original case to avoid damage.
3. Be sure to have the unit and electrics fitted by qualified electrician.
4. Ensure that no building materials or debris are allowed to enter the air ducts at the top of the unit or
any extension of the ducts.

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ESP400-10-200L and 300L
4.1 Some Notes on Ducting:
The maximum length of the ducting (input plus exhaust) that can be attached to the Ecocent is 16m. All ducting
should be 150mm or split into two ducts of not less than 108mm diameter.
The outlets should be fitted with a suitable gravity vent to prevent rain, debris, animals and plants entering the
ducts.
You can use rigid or flexible ducting. Insulated ducting must be used so that condensation is avoided. It also
has the added benefit of reducing any airflow noise.
When servicing the unit, ducting should be checked to make sure that it is clear and all obstructions must be
removed.
4.2 Water Supply:
Because water composition can vary greatly, it is not ESP’s policy to issue recommendations relating to water
treatment. The user or the owner is responsible for contacting a specialized water treatment company to obtain
water treatment advice appropriate to your location. Appropriate water treatment processes/devices must be
fitted to ensure the longevity of the unit and its proper operation.
Bear in mind that the mains water supply to the property will be supplying both the hot and cold water
requirements simultaneously. Therefore, it is important that the maximum water demand be assessed
and the water supply checked to ensure that it can meet peak demand.
NOTE: A high mains water pressure will not always guarantee high flow rates. The main supply pipe to the unit
must be 22mm. The minimum mains water supply requirements should be 0.15 MPa (1.5 bar) working pressure
and 20 litres per minute flow rate at the Ecocent. At these levels, outlet flow rates may be poor if several outlets
are used simultaneously – the higher the available pressure and flow-rate the better the system performance will
be.
The unit has a design operating pressure of 3 bar which is controlled by the Cold Water Combination
Valve on the cold water feed pipework. The Cold Water Combination Valve can be connected to a maximum
mains supply pressure of 1.5 MPa (15 bar). The water supply must be of wholesome water quality (Fluid
Category 1 as defined by the Water Supply Regulations 1999).
The unit MUST be level, otherwise this could cause problems with condensate draining from the heat pump
section of the unit in to the condensate drain.
An inline strainer (if open vented) and scale inhibitor (WRAS approved) must be fitted “in line” on the water
supply to the unit. Failure to fit these will invalidate the unit warranty/guarantee. All fittings must be
WRAS approved.
If installing the unit in unvented configuration, an “unvented Pack”, containing the required safety valves must
be supplied with the unit and there is likely to be an additional cost for this.
4.3 Outlet/Terminal Fittings (Taps etc.):
The unit can be used in conjunction with most types of terminal fittings. It is helpful in many mixer showers to
have balanced hot and cold water supplies; in these instances the balanced cold water supply can be taken
from the tapping on the combination valve . Branches to cold drinking water outlets should be taken before the
combination valve.
NOTE: Accessories should have a rated operating pressure of at least 0.8 MPa (8 bar).
4.4 Limitations:
The unit should not be used in any of the following instances:

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ESP400-10-200L and 300L
With a water supply from solid fuel boilers or any other boiler in which the energy input is not under
effective thermostatic control, unless additional, necessary and appropriate safety measures are
installed.
With gravity circulation primaries unless a good head of pressure is available.
With steam heating plant unless additional and appropriate safety devices are installed.
With ascending spray type bidets or any other facility where there is a Class 5 back siphoning risk
requiring that an appropriate air gap be employed.
With water supplies that have either inadequate pressure or where the supply may be intermittent.
In situations where it is not possible to pipe away any discharge from the safety valves safely.
In areas where the water contains a high proportion of solids, e.g. suspended matter that could block
the strainer, unless adequate filtration can be ensured.
Where another appliance in the room is vented by way of an open flu.
The installation must be carried out in accordance with the relevant requirements of:
A) The appropriate Building Regulations: either The Building Regulation (England and Wales), The
Building Regulations (Scotland) or Building Regulations (Northern Ireland).
B) The Water Fittings Regulations (England and Wales) or Water Bye laws (Scotland).
C) Any other applicable Regulations.
Failure to observe any of the above conditions will invalidate the warranty/guarantee.
4.5 Hot Water Air Source Heat Pump Package:
Where the unit is to be installed as an unvented system it will be supplied with the fittings needed to allow
installation to comply with G3 Regulations – This means that the supply cost for the unvented
configuration unit will be higher than when installed as a vented system as additional fittings are required.
Where the unit is to be installed in a vented system, such fittings will not be necessary.

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ESP400-10-200L and 300L
4.6 Basic System Schematic:
The following is a basic layout of an Ecocent system:

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ESP400-10-200L and 300L
5.0 Specifications:
5.1 Appearance:
Good Looking and Efficient
The attractive design allows the unit to be placed in the open in finished utility spaces and basements; depending
on ambient conditions, the cost of operation can be up to 75% less of that of an electric water heater, and can be
used in locations unsuitable for solar hot water heating.
Environmentally friendly and safer
The unit produces no harmful emissions locally; there is no combustion of oil, coal, or natural gas. No carbon
monoxide is produced and there is no open flame.
Easy to operate and multiple heat sources
The Ecocent is equipped with a timer for automatic start-up and stop and an adjustment for the easy setting of
water temperature. The unit can take heat from a number of sources in domestic installations, or from hot areas
in light industrial environments.
Controller
Water
Storage
Tank
Air Outlet
Air Inlet

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ESP400-10-200L and 300L
5.2 Dimensions:
200L Ecocent
Dimension
(mm)
A
1705
B
1050
C
665
D
305
E
Ø560

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ESP400-10-200L and 300L
300L Ecocent
Dimension
(mm)
A
1820
B
1180
C
640
PLEASE NOTE: The Ecocent is supplied with 2 Secondary Coils.

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ESP400-10-200L and 300L
5.3 Performance:
Units
ESP400-010-200l(D)
ESP400-010-300l(D)
Heating Capacity
kW
2.3
2.3
Water Tank Capacity
L
200
300
Power input
kW
0.64
0.64
Running Current
A
2.78
2.78
Power Supply
230v/50hZ
230v/50hZ
Number of Compressors
1
1
Compressor Type
Rotary
Rotary
Rated Outlet Temp
°C
55
55
Air Volume
M3/hr
350
350
Air Pressure
Pa
40
40
Duct Diameter
Mm
150
150
Noise
dB(A)
45
45
Water Connection Size
inch
¾
¾
Electric Heater
kW
1.5
1.5
Operating Temp Range
°C
0-43
Max Water Tank Temp
°C
60
Operating Water Temp Range
°C
9-60
Water Pressure Range
MPa
0.15-0.7
Net Dimensions
mm
See Drawings above
Shipping Dimensions
mm
See Package Label
Net Weight
kG
See Nameplate
Shipping Weight
kG
See Package Label
5.3.1 Performance Assumptions:
Heating Capacity
The unit absorbs energy from the air taken in through the inlet ductwork. If the air inlet temperature is low,
heating capacity will show a variation from standard conditions.
3 Minutes Protection
When the unit stops, if you try to immediately restart the unit or turn on the manual switch, the unit will not run
for 3 minutes. This is built in protection for the compressor.
Heating Mode Operating
If the ambient temperature is very high, to protect the unit, the fan motor will stop running.
Defrosting
When in heating mode, the unit will defrost automatically, if required. The fan motor will stop running when the
unit is defrosting.
Working Conditions
The unit should be run in ambient temperatures of 0-40 deg. The unit includes sophisticated electronic devices -
do not fill the Ecocent with water from a lake, river water or groundwater and be sure to put an inline strainer
(open vented) and scale inhibitor in the cold water feed- failure to do so will invalidate the warranty/guarantee.
Standing Heat Losses
The amount of heat that the Ecocent loses through convection to the surrounding area (standing heat loss) is
dependent on a number of things including, for example, the target temperature (see section 8), the ambient air
temperature surrounding the unit and the number of secondary coils (and, therefore, tappings) on the unit. The
target temperature is an end user choice and the ambient temperature will depend on location; clearly if the unit
is in and ‘airing cupboard’, the ambient temperature will be more than if it is located in, say, a utility room; the
higher the ambient air temperature, the lower the rate of heat loss. However, an illustrative heat loss for the
Ecocent is as follows in an ‘average’ location and a target temperature of 55°C:
Ecocent Size
Heat Loss/24hrs
300l
2.26kWh
200l
1.84kWh

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ESP400-10-200L and 300L
5.4 DHW Recovery times:
The recovery time of your Ecocent (the time it takes to return to fully hot) depends on the storage temperature
(normally 55°C), the temperature of your cold water supply (normally taken to be 10°C), the temperature of the
air supply (at least 15°C) and the amount of water you use. Typically, a single person uses about 45l of hot
water per day. However, it would be unusual to use all this hot water at the same time. A shower uses around
30l and a bath uses around 65l. The recovery times based on proscribed test data (20°C input air temperature
and 55°C flow temperature)are as follows:
Volume
Time
10l
9 mins
15l
14 mins
20l
19 mins
30l
28 mins
40l
37 mins
65l
33mins
In fact, the recovery times could well be even better than this because the air source will probably be warmer
and more humid than that used to calculate the above tables.
Your Ecocent unit will have been sized based upon normal DHW use profiles and volumes and, save in
exceptional circumstances (e.g. visitors using shower/bath), you should not run out of hot water. Should your
usage exceed normal expectation, the immersion heater can be used to provide a boost. In fact, in the unusual
event that the target temperature (normally 55°C) is not reached within 200 mins, the immersion heater will
automatically provide that boost in normal heating mode (see section on modes).
The efficiency of the Ecocent can also be measured in terms of how much energy (heat) it saves when
generating DHW, both in terms of low running cost and effective use of heat used in generating the DHW.
European standard M324, Table 2 (and UK Government SAP process) indicates a typical household DHW
demand is 100 ltrs per day. To raise this amount of water to 55 deg C and when that water is used/drawn off in
a use profile indicated by European “best practice” as seen in document M324 (this uses various “draw offs” to
a standardised pattern over a 24 hour period totalling 100 ltrs) takes 5.8kWhs of heat.
The cost of producing and delivering the required kWh of heat to produce that much DHW for a 24hr period is
dictated by the efficiency (COP) of the unit generating the heat. Using document M324 process/draw-off and
calculation methodology and taking the Ecocent COP as being 2.4 (because of the relatively high number of
draw-offs in small amounts at high water temperatures to a total to 100 ltrs overall 24 hour demand) this amount
of DHW might take approx. 2.41 kWh of electricity to produce. If you assume a cost of 1 kWh of electricity to
be 13p, the cost of generating the 100 ltrs of DHW would be 2.41 X 13p = 31.3p.
Whilst this is a very significant saving when compared to many other fuels used to deliver the heat required, it
should also be remembered that the heat being delivered in to the water to create DHW is coming from areas
within the house where that heat would have been totally wasted (expelled from the house by extractor fans) or
very inefficiently used.
Because the draw-off pattern experienced by most of our Ecocent customers is slightly different to the pattern
used in the ‘standard’ tests, the economy is even greater in practice and we are told that heating the same
amount of water (100ltrs) is up to 10p less than the laboratory tests would indicate. Also to be kept in mind is
the fact that you will not be paying for an extractor fan to remove heated air from some of the potential places
where the Ecocent draws heat from – so a lower air handling cost because the Ecocent works with a lower
system pressure differential and smaller fan than an extractor fan unit does. For example, when the Ecocent is
drawing air/heat/moisture from a bathroom, an extractor fan will not be running to expel the heat laden air to
outside and the motor on an extractor fan is usually larger than the motor on an Ecocent – so you will effectively
be running the Ecocent for nothing and generating DHW using heat that would otherwise be completely wasted.
Whilst this indicates the principles of costs and savings associated with the Ecocent in terms of varying
Standards measurement criteria, it also demonstrates is that it is important to consider carefully where you draw
air/heat from to generate DHW – savings generated by the Ecocent are almost always significant, but can be

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ESP400-10-200L and 300L
maximised through careful design and heat use planning. The supplier/installer of your Ecocent unit should
always be prepared to assist you with this.
6.0 INSTALLATION
6.1 INSTALLATION DIAGRAM:
Where the unit is installed to draw in air, or dispose of air, from sites more than 8mtrs from the unit a
booster fan must be fitted within the ducting and wired in a manner that the additional fan will run only
when the fan within the unit is running.
6.2 Indirect Thermal Cut-Out (DUAL STAT) and 2-Port Motorised Valve
To comply with Building Regulations and to prevent the unit from overheating a 2-port motorised valve MUST
be fitted to the primary flow to the indirect coil(s). Please note that this diagram may vary from model to model,
but the principle does not.
6.3 Pipe Fittings:
All pipe connections to the unit are 22mm. The fittings are also threaded 3/4” BSP male. Air ducts must be at
least 150mm in internal diameter. It is recommended that you use insulated ducting on both inlet and outlet
ducts.
6.4 Cold Water Supply:
A 22mm cold water supply is recommended, however, if a 15mm (1/2”) supply exists which provides sufficient
flow (see section 2.3) this may be used. More flow noise may be experienced from small bore pipes due to the
increased water velocity through them. The Cold Water Combination Valve supplied with the unit
incorporates a full flow isolating valve which will enable the unit to be isolated from the mains supply for
maintenance or servicing. To close the valve the black handle should be turned so that it lies at 90° to the
direction of flow. To open turn the handle so that it lies parallel to the direction of flow.
An inline filter (open vented) and an effective scale prevention device must be fitted to the cold feed inline
before the feed reaches the unit.
6.5 Cold Water Combination Valve (see Figure 2):
The Cold Water Combination Valve must be sited close enough to the unit to allow the safety discharge pipe
to run in to the tundish, in line with appropriate Regulations. The expansion (safety valve) must not be used
for any other purposes. Under no circumstances is the expansion vessel to be connected to the balanced cold
Unless requested, air
ducting not supplied,
because we don’t
know how much will be
required for your
particular project

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ESP400-10-200L and 300L
outlet on the combination group valve. The Cold Water Combination Valve can be installed as a complete one
piece unit. The valve incorporates a factory set, non-adjustable Pressure Reducer/ Strainer, an Expansion Valve
connection a single Check Valve and balanced cold feed. 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 unit (in the direction of the flow of water).
If a balanced pressure cold water supply is required to a thermostatic shower mixer valve this must be supplied
from the cold water balance outlet (see figure 2). Branches to drinking water outlets should be taken before the
combination group valve to avoid the possibility of warm expanded water being drawn from the tap.
Figure 2:
Cold water balance
outlet
6.6 Drain-Off Cock:
The unit is fitted with a drain-cock and this is used for draining down the unit. You must ensure that this is
accessible and that a hosepipe can be easily attached to allow water from the unit to be drained down.
6.7 Outlet Pipe Work:
Ideally, the pipe work from the unit’s 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 particulars.
6.8 Secondary Circulation of Domestic Hot Water:
Secondary circulation is not recommended but, if a secondary circulation system is required, it should be
installed as per Figure 6. 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 with appropriate
unions. 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)
Secondary circulation is NOT recommended for units being used on “Off Peak” electricity tariffs.

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Whilst secondary returns do make for greater comfort by having hot water immediately available at taps, it is an
energy sapping facility – it is recommended that all secondary returns should be fitted with timers so that
circulation is not constant.
PLEASE NOTE: All secondary return pipework MUST be very well insulated and, even then,
may have a very detrimental impact upon the economics of generating hot water.
6.9 Temperature and Pressure Relief Valve (“TPRV”):
The TPRV is factory fitted and must not be interfered with in any way and/or removed - under NO
circumstances should the installer or end user tamper with the TPRV or the warranty/guarantee for
the unit will be invalidated and serious damage may result. If the TPRV fails it should only be
replaced by a qualified installer under the following regulations –
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).
6.10 Warnings:
i) Under no circumstances should the factory fitted TPRV be removed other than by
approved, fully trained and experienced fitters. To do so will invalidate any
warranty/guarantee or claim.
ii) The Cold Water Combination Valve, in line strainer and scale inhibiting device must be
fitted to the mains water supply to the unit.
iii) No control or safety valves should be tampered with.
iv) Water may drip from the discharge pipe of the TPRV and this pipe must be left open to
atmosphere. The discharge pipe should not be blocked or used for any other purpose.

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v) For units with secondary coil facilities, please discuss the use of the coil, and a suitable
configuration for use, with a suitably qualified plumber/engineer before proceeding to add a
heat source to the secondary coil.
6.11 Discharge Pipe Work:
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. Information Sheet No. 33, available from the British Board of Agreement gives further
advice on discharge pipe installation. For discharge pipe arrangements not covered by G3 Guidance
or BBA Info Sheet No.33, 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 metal, in a continuously downward direction and in a frost free
environment. The water may drip from the discharge pipe of the pressure relief device this pipe must
be left open to the atmosphere. The pressure relief device is to be operated regularly to remove lime
deposits and to verify that it is not blocked.
Please see figure 7 for typical discharge arrangement.
6.12 Expansion Vessel:
An appropriately sized expansion vessel must be fitted to the system in which the unit is incorporated.
The Expansion vessel can be fitted to the cold feed in to the unit (see Figures 4 and 6).
6.13 G3 Requirement:
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).
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.
6.14 G3 Guidance Section:
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 and within 500mm of the safety device(s) e.g. the TPRV. 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, be of metal
and:
a) be at least one pipe size larger than the nominal outlet size of the safety device unless its total
equivalent hydraulic resistance exceeds that of a straight pipe 9m long i.e. discharge pipes between 9m
and 18m equivalent resistance length should be at least two sizes larger than the nominal outlet size of
the safety device, between 18 and 27m at least 3 sizes larger, and so on. Bends must be taken into
account in calculating the flow resistance. Refer to figure 7 and Table 1 below. An alternative
approach for sizing discharge pipes would be to follow BS6700:1987 Specification for design,
installation, testing and maintenance of services supplying water for domestic use within buildings and
their curtilages, Appendix E, section E2 and table 21.
b) Have a vertical section of pipe at least 300mm long below the tundish before any elbows or bends
in the pipe work.
c) Be installed with a continuous fall, and in a frost free environment.
d) Have discharges visible at both the tundish and the final point of discharge, but where this is not
possible or is practically difficult there should be clear visibility at one or other of these locations.

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Examples of acceptable discharge arrangements are:
i. ideally below a fixed grating and above the water seal in a trapped gully.
ii. 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 where children may play
or otherwise come into contact with discharges a wire cage or similar guard is positioned to
prevent contact, whilst maintaining visibility.
iii. discharges at high level; e.g. into a metal hopper and metal down pipe with the end of the
discharge pipe clearly visible (tundish visible or not) or onto a roof capable of withstanding
high temperature discharges of water and 3m from any plastic guttering system that would
collect such discharges (tundish visible).
iv. where a single pipe serves a number of discharges, such as in blocks of flats, the number
served should be limited to not more than 6 systems so that any installation discharging can be
traced reasonably easily. The single common discharge pipe should be at least one pipe size
larger than the largest individual discharge pipe (D2) to be connected. If unvented hot water
storage systems are installed where discharges from safety devices may not be apparent i.e. in
dwellings occupied by blind, infirm or disabled people, consideration should be given to the
installation of an electronically operated device to warn when discharge takes place.
Note: The discharge will consist of very high temperature water and steam. Asphalt, roofing felt and
non-metallic rainwater goods may be damaged by such discharges and you must take this in to account
when fitting the unit. Should such damage be caused, ESP will accept no liability for any consequent
damage so caused.
Table 1 - Sizing of copper discharge pipe (D2) for common T&P relief valve sizes
7.0 HOW TO CONNECT TO THE HEAT PUMP
As the heat pump is an integral part of the unit, there are no special requirements for attaching the heat pump to
the integrated cylinder – all mechanical and electrical connections are factory made.