Estia HWS-1501CSHM3-UK Manual

1
AIR TO WATER HEAT PUMP SYSTEM
HOT WATER CYLINDER
INDIRECT HEATING METHOD
CLOSED OUTLET (UNVENTED)
INSTALLATION AND SERVICE MANUAL
36006030_Issue_H
HWS-1501CSHM3-UK
HWS-2101CSHM3-UK
HWS-3001CSHM3-UK

2
INSTALLATION AND SERVICING INSTRUCTIONS, FOR AIR TO WATER HEAT
PUMP SYSTEM WATER CYLINDER. PLEASE LEAVE THIS MANUAL WITH THE
UNIT FOR FUTURE REFERENCE.
CONTENTS
SECTION CONTENT PAGE
1 INTRODUCTION . . . . . . . 2
2 GENERAL REQUIREMENTS . . . . . . 3
3 INSTALLATION - GENERAL . . . . . . 4
4 INSTALLATION – INDIRECT UNITS . . . . . 9
5 COMMISSIONING . . . . . . . 9
6 MAINTENANCE . . . . . . . 10
7 FAULT FINDING AND SERVICING . . . . . 11
8 USER INSTRUCTIONS . . . . . . 13
9 GUARANTEE . . . . . . . . 14
1.0 INTRODUCTION
IMPORTANT: THIS APPLIANCE IS NOT
INTENDED FOR THE USE BY PERSONS
(INCLUDING CHILDREN) WITH REDUCED
PHYSICAL, SENSORY OR MENTAL CAPABILI-
TIES, OR LACK OF KNOWLEDGE AND EXPE-
RIENCE, UNLESS THEY HAVE BEEN GIVEN
SUPERVISION OR INSTRUCTION CONCERN-
ING THE USE OF THE APPLIANCE BY A PER-
SON RESPONSIBLE FOR THEIR SAFETY.
This unit, for use with the ESTIA air to water heat
pump system, is a purpose designed unvented water
cylinder. The unit has a stainless steel inner vessel
which ensures an excellent standard of corrosion re-
sistance. The outer casing is a combination of resilient
thermoplastic mouldings and plastic coated corrosion
proofed steel sheet. NOTE: Prior to installation the unit should be stored
in an upright position in an area free from excessive
damp or humidity.
The unit is supplied complete with all the necessary
safety and control devices needed to allow connec-
tion to the cold water mains. All these components
are pre-adjusted.
This appliance complies with the requirements of the
CE marking directive and is KIWA approved to show
compliance with Building Regulations (Section G3)
and UK Water Regulations.
The following instructions are offered as a guide to
installation which must be carried out by a competent
plumbing and electrical installer in accordance with
Building Regulation G3, The Building Standards
(Scotland) Regulations Section 4 standard 4.9, or
The Building Regulations (Northern Ireland) Part P
Section P5.
IMPORTANT: PLEASE READ ALL THESE INSTRUCTIONS BEFORE
COMMENCING INSTALLATION
Maximum water supply pressure to PRV 1.6MPa (16.0 bar)
Operating pressure of unit 0.35MPa (3.5 bar)
Expansion vessel charge pressure 0.35MPa (3.5 bar)
Expansion valve setting 0.6MPa (6.0 bar)
Nominal storage capacity of units (see Table 2)
Max. primary working pressure 0.3MPa (3.0 bar)
Opening temperature of T&P Relief Valve 90deg C
Opening pressure of T&P Relief Valve 1.0 MPa (10 bar)
Table 1: Operational Summary

3
2.0 GENERAL REQUIREMENTS
2.1 COMPONENTS SUPPLIED
1. Unvented water cylinder incorporating
cylinder heater and thermal controls
2. Factory tted Temperature/Pressure Relief Valve
3. T&P Valve insulation and housing.
4. Cold Water Combination Valve.
5. Expansion Vessel and mounting bracket.
6. Tundish.
7. Compression nuts and olives
8. Cylinder heater key spanner
2.2 SITING THE UNIT
The unit must be installed vertically. Although loca-
tion is not critical, the following points should be
considered:
• The unit should be sited to ensure minimum dead
leg distances, particularly to the point of most frequent
use.
• Avoid siting where extreme cold temperatures
will be experienced. All exposed pipework should be
insulated.
• The discharge pipework from the safety valves
must have minimum fall of 1:200 from the unit and
terminate in a safe and visible position.
• Access to associated controls and cylinder heater
should be possible to allow for periodic servicing and
maintenance.
• Ensure that the base chosen for the unit is level
and capable of permanently supporting the weight
when full of water (see Table 2).
2.3 WATER SUPPLY
Bear in mind that the mains water supply to the
property will be supplying both the hot and cold wa-
ter requirements simultaneously. It is recommended
that the maximum water demand is assessed and the
water supply checked to ensure this demand can be
satisfactorily met.
NOTE:A high mains water pressure will not always
guarantee high ow rates.
Wherever possible the mains supply pipe should be
22mm. We suggest the minimum supply requirements
should be 0.15MPa (1.5 bar) pressure and 20 litres
per minute owrate. However, at these values outlet
owrates may be poor if several outlets are used si-
multaneously. The higher the available pressure and
owrate the better the system performance.
The unit has an operating pressure of 0.35MPa (3.5
bar) that is controlled by the Cold Water Combination
Valve. The Cold Water Combination Valve can be
connected to a maximum mains pressure of 1.6MPa
(16 bar).
2.4 OUTLET/TERMINAL FITTINGS (TAPS, ETC.)
The unit can be used with most types of terminal t-
tings. It is advantageous in many mixer showers to
have balanced hot and cold water supplies. In these
instances a balanced pressure cold water connection
should be placed between the Cold Water Combination
Valve and the water cylinder. Outlets situated higher
than the unit will give outlet pressures lower than that
at the cylinder, a 10m height difference will result in a
0.1MPa (1 bar) pressure reduction at the outlet.
2.5 LIMITATIONS
The unvented water cylinder should not be used in
association with any of the following:
• Ascending spray type bidets or any other class 1
back syphonage risk requiring that a type A air gap
be employed.
• Situations where maintenance is likely to be
neglected or safety devices tampered with.
• Water supplies that have either inadequate pres-
sure or where the supply may be intermittent.
• Situations where it is not possible to safely pipe
away any discharge from the safety valves.
• In areas where the water consistently contains a
high proportion of solids, e.g. suspended matter that
could block the strainer, unless adequate ltration can
be ensured.
Table 3: Standing heat losses
Table 2: Unit weights
Based on an ambient air temperature of 20oC and a
stored water temperature of 65oC
Nominal
capacity
(litres)
W eight of
unit full
(kg)
HWS-1501CSHM3-UK 150
210
300
HWS-2101CSHM3-UK
HWS-3001CSHM3-UK
181
251
360
Model
Nom ina l
capa city pe r da y pe r ye a r
(litres ) (kW h/24h) (kW h/365d)
150 1.45 529.3
210 1.91 697.2
300 2.52 919.8
Sta nding He a t Loss

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3.0 INSTALLATION – GENERAL
3.1 PIPE FITTINGS
All pipe ttings are made via 22mm compression
ttings directly to the unit. The ttings are threaded
3/4”BSP male parallel should threaded pipe connec-
tions be required.
3.2 COLD FEED
A 22mm cold water supply is recommended however,
if a 15mm (1/2”) supply exists which provides suf-
cient ow this may be used (although more ow
noise may be experienced).
A stopcock or servicing valve should be incorporated
into the cold water supply to enable the unit and its
associated controls to be isolated and serviced.
3.3 COLD WATER COMBINATION VALVE (FIG 1)
The Cold Water Combination Valve can be connected
anywhere on the cold water mains supply prior to the
Expansion Vessel (see Fig. 5). The Cold Water Com-
bination Valve is installed as a complete one-piece
unit. The valve incorporates the Pressure Reducer,
Strainer, Expansion Valve and Check Valve. Ensure
that the valve is installed with the direction of ow
arrows pointing in the right direction. No other valves
should be placed between the Cold Water Combination
Valve and the unit. The Expansion Valve connection
must not be used for any other purpose.
FIG. 1 Cold Water Combination Valve FIG. 2 Secondary circulation connection
3.4 DRAIN TAP
A suitable draining tap should be installed in the
cold water supply to the unit between the Cold Water
Combination Valve and the cylinder at as low a level
as possible. It is recommended that the outlet point of
the drain pipework be at least 1 metre below the level
of the cylinder (this can be achieved by attaching a
hose to the drain tap outlet spigot).
3.5 EXPANSION VESSEL
The Expansion Vessel accommodates expansion that
results from heating the water inside the unit. The unit
is pre-charged at 0.35MPa (3.5 bar). The Expansion
Vessel must be connected between the Cold Water
Combination Valve and the water cylinder (see Fig.
5). The location of the Expansion Vessel should
allow access to recharge the pressure as and when
necessary, this can be done using a normal car foot
pump. It is recommended that the Expansion Vessel
is adequately supported. An Expansion Vessel wall
mounting bracket is supplied for this purpose
3.6 SECONDARY CIRCULATION
If secondary circulation is required it is recommended
that it be connected to the cylinder as shown in Fig. 2
via a swept tee joint into the cold feed to the unit.
The secondary return pipe should be in 15mm pipe
and incorporate a check valve to prevent backow. 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 t an
additional expansion vessel to the secondary circuit.
this should be done if the capacity of the secondary
circuit exceeds 10 litres.
Pipe capacity (copper)
15mm o/d = 0.13 l/m (10 litres = 77m)
22mm o/d = 0.38 l/m (10 litres = 26m)
28mm o/d = 0.55 l/m (10 litres = 18m)
3.7 OUTLET
The hot water outlet is a 22mm compression tting
located at the top of the cylinder. Hot water distribu-
tion pipework should be 22mm pipe with short runs
of 15mm pipe to terminal ttings such as sinks and
basins. Pipe sizes may vary due to system design.
EXPANSION VALVE
COLD MAINS
CONNECTION
(22mm)
EXPANSION VALVE
OUTLET (15mm)
OUTLET
CONNECTION
(22mm)
PRESSURE
REDUCING
VALVE
HOUSING
PRESSURE
REDUCING
VALVE
CARTRIDGE (3.5 bar)
COLD
INLET
CONNECTION
COLD
SUPPLY
CHECK
VALVE SECONDARY
RETURN
SECONDARY
CIRCULATION
PUMP
SWEPT
TEE

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FIG. 3 General Dimensions and Performance
NOMINAL CAPACITY (litres)
A (mm)
B (mm)
C (mm)
D (mm)
SURFACE AREA (sq.m)
HOT WATER OUTPUT AT 60ºC (litres)
MIXED HOT WATER OUTPUT AT 40ºC (litres)
HEAT LOSS (kWh/24h)
HEATING TIME 15ºC TO 60ºC - USING ELECTRIC
CYLINDER HEATER ONLY (mins)
CAPACITY HEATED USING ELECTRIC
CYLINDER HEATER ONLY (litres)
150 210 300
315 315 315
354 354 354
800 1184 1474
1090 1474 2040
0.65 0.79 0.79
102 163 254
243 329.5 476
1.45 1.91 2.52
123 188 262
102 163 254

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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 dis-
charge.
From Table 4:
Maximum resistance allowed for a straight length of
22mm copper discharge pipe (D2) from a G1/2 tempera-
ture relief valve is 9.0m.
Subtract the resistance for 4 No. 22mm elbows at 0.8m
each = 3.2m
Therefore the permitted length equates to: 5.8m
5.8m is less than the actual length of 7m therefore calcu-
late the next largest size.
Maximum resistance allowed for a straight length of
28mm pipe (D2) from a G1/2 temperature relief valves
equates to 18m.
Subtract the resistance of 4 No. 28mm elbows at 1.0m
each = 4.0m
Therefore the maximum permitted length equates to:
14m
As the actual length is 7m, a 28mm (D2) copper pipe
will be satisfactory.
3.8 DISCHARGE PIPEWORK
It is a requirement of Building Regulation G3 that any
discharge from an unvented system is conveyed to
where it is visible, but will not cause danger to persons
in or about the building. The tundish and discharge
pipes should be tted in accordance with the require-
ments and guidance notes of Building Regulation G3.
The G3 Requirements and Guidance section 3.9 are
reproduced in the following sections.
Information Sheet No. 33 available from the British
Board of Agrement 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 either your local Build-
ing Control Ofcer.
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 3.9
The discharge pipe (D1) from the vessel up to and
including the 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 tted as close as possible and within 500mm of the
safety device e.g. the temperature relief valve.
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, preferably
be of metal and:
a. be at least one pipe size larger than the nominal
outlet size of the safety device unless its total equiva-
lent 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 ow resistance. Refer to Diagram
1, Table 1 and the worked example.
An alternative approach for sizing discharge pipes
would be to follow BS 6700:1987 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 pipework.
c. be installed with a continuous fall.
d. have discharges visible at both the tundish and the
nal point of discharge but where this is not possible
or is practically difcult there should be clear vis-
ibility at one or other of these locations. Examples of
acceptable discharge arrangements are:
i. ideally below a xed 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 plastics guttering system
that would collect such discharges (tundish visible).
iv. where a single pipe serves a number of discharges,
such as in blocks of ats, the number served should
be limited to not more than 6 systems so that any
instalation discharging can be traced reasonably eas-
ily. 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 dwell-
ings occupied by blind, inrm 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 scalding water and
steam. Asphalt, roong felt and non-metallic rainwater
goods may be damaged by such discharges.

7
Fixed grating
Discharge below
fixed grating
(Building Regulation
G3 section 3.9d gives
alternative points
of discharge)
Trapped
gully
Discharge pipe (D2) from tundish,
with continuous fall. See Building
Regulation G3 section 3.9d i-iv,
Table 4 and worked example
300mm
minimum
500mm maximum
Metal discharge pipe (D1) from
Temperature relief valve to tundish
Tundish
Safety device
(e.g. Temperature
relief valve)
Table 4 Sizing of copper discharge pipe (D2) for common temperature relief valve outlet
FIG. 4 Typical discharge pipe arrangement (extract from Building Regulation G3 Guid-
ance section 3.9)
Va lve outle t size Minim um size of
discha rge pipe
D1
Minimum size of
discharge pipe
D2 from tundish
Maxim um
re sista nce
allow e d,
expre sse d a s a
le ngth of stra ight
pipe (I.e. no
elbow s or bends)
Resistance
create d by each
elbow or be nd
G1/2 15mm
22mm
28mm
35mm
up to 9m
up to 18m
up to 27m
0.8m
1.0m
1.4m
G3/4 22mm
28mm
35mm
42mm
up to 9m
up to 18m
up to 27m
1.0m
1.4m
1.7m
G1 28mm
35mm
42mm
54mm
up to 9m
up to 18m
up to 27m
1.4m
1.7m
2.3m
3.9 WARNINGS
• Under no circumstances should the factory tted
Temperature Relief Valve be removed other than by
an authorised installer. To do so will invalidate any
guarantee or claim.
• The Cold Water Combination Valve must be tted
to the mains water supply to the unit.
• No control or safety valves should be tampered
with.
• The discharge pipe should not be blocked or used
for any other purpose.
• The tundish should not be located adjacent to any
electrical components.

8
FIG. 5 Typical installation - schematic
FIG. 6 Electrical Connections (Schematic)
EXPANSION
VESSEL
COLD WATER
COMBINATION
VALVE
T&P RELIEF
VALVE
TO HOT
OUTLETS
MAINS
WATER
SUPPLY
ISOLATING
VALVE (NOT
SUPPLIED)
TUNDISH
DISCHARGE
PIPE
DRAIN COCK
(NOT SUPPLIED)
PRIMARY
RETURN
PRIMARY
FLOW
ELEMENT /
CONTROLS
HOUSING
INLET
SECONDARY
RETURN
TAPPING (IF
REQUIRED)
BALANCED
COLD WATER
CONNECTION
(IF REQUIRED)
1
GREEN/YELLOW
230V~ MAINS SUPPLY
FROM HYDRO UNIT.
2
1.5mm MIN. CABLE SIZE
GREEN/
YELLOW
BROWN
2
DOUBLE POLE THERMAL
CUT-OUT
AB
BLUE
BLUE
BROWN
SENSOR
TO HYDRO UNIT
TBO6 (TTW)
TBO3 (230V)

9
4.0 INSTALLATION - INDIRECT
UNITS
4.1 PLUMBING CONNECTIONS
The water cylinder requires the following pipework
connections.
• Cold water supply to and from inlet controls.
• Outlet to hot water draw off points.
• Discharge pipework from valve outlets to
tundish
• Connection to the primary circuit. Refer to the
Hydro Unit Installation Instructions for details.
Primary connections are 22mm compression. How-
ever, 3/4”BSP parallel threaded ttings can be tted
to the primary coil connections if required.
4.2 ELECTRICAL SUPPLY (FIG. 6)
All units are tted with a 2.75kW (230V) cylinder
heater and a thermal cut-out to supplement the Air to
Water heat pump primary heating. The unit MUST
be earthed.
All wiring to the unit must be installed in accordance
with the latest IEE Wiring Regulations and the sup-
ply circuits must be protected by a suitable fuse and
double pole isolating switch with a contact separation
of at least 3mm in both poles.
ISOLATE FROM MAINS SUPPLY BEFORE
REMOVING ANY COVERS. DO NOT BYPASS
THE THERMAL CUT-OUT IN ANY CIRCUM-
STANCES. Ensure the thermal sensor and thermal
cut-out sensing bulbs are pushed fully into the pockets
on the element plate assembly.
All wiring to the unit must be via the controls housing
on the Hydro Unit. Direct connection of the cylinder
heater to the mains electrical supply will invalidate
the guarantee and may result in a dangerous instal-
lation. Refer to the wiring details in the Hydro Unit
Installation Manual.
The supply cable to the cylinder heater must be routed
through the right hand cable gland provided and the
outer sheath of the cable rmly secured by tightening
the cable gland. Connection must be to the terminal
block marked ‘TB03 (230V)’. The recommended
cable type is 2.5mm2 3 core heat resistant sheathed.
The thermal sensor connection cable must be routed
through the left hand cable gland provided and the
outer sheath of the cable rmly secured by tightening
the cable gland. Connection must be to the terminal
block marked ‘TB06 (TTW)’. The sensor cable should
be 0.75mm2 2 core and shield (ground) with a maxi-
mum current rating of 100mA. The cable shielding
wire must be connected to the terminal marked on
the sensor terminal block.
Thermal control of the water cylinder is managed by
the Heat Pump controls on the Hydro Unit. Refer to
the Hydro Unit Installation Manual for details of how
to set up the thermal control. The electrical supply
from Hydro Unit to the cylinder heater incorporates
an over temperature thermal cut-out that will switch
off the heater in the event of a thermal control failure.
The thermal cut-out must not be bypassed in any
circumstances.
5.0 COMMISSIONING
Warning: Water that is left standing in a stainless
steel water cylinder for long periods without draw
off will become de-oxygenated and potentially cor-
rode the vessel material. If the installation is to be
left unused following installation and commission-
ing the water cylinder should be drained or regu-
larly (once per week) ushed through with fresh
mains water.
5.1 FILLING THE UNIT WITH WATER
• Check Expansion Vessel pre-charge pressure. The
vessel is supplied pre-charged to 0.35MPa (3.5 bar) to
match the control pressure of the Pressure Reducing
Valve. The pre-charge pressure is checked using a car
tyre gauge by unscrewing the plastic cap opposite the
water connection.
• Check all connections for tightness including
the cylinder heater. A cylinder heater key spanner is
supplied for this purpose.
• Ensure the drain cock is CLOSED.
• Open a hot tap furthest from the water cylinder.
• Open the mains stop cock to ll the unit. When
water ows from the tap, allow to run for a few min-
utes to thoroughly ush through any residue, dirt or
swarf, then close the tap.
• Open successive hot taps to purge the system of
air.
5.2 SYSTEM CHECKS
• Check all water connections for leaks and rectify
as necessary.
• Remove the Pressure Reducing Valve headwork
to access the strainer mesh, clean and re-t.
• Manually open, for a few seconds, each relief
valve in turn, checking that water is discharged and
runs freely through the tundish and out at the discharge
point.
• Ensure that the valve(s) reseat satisfactorily.
5.3 PRIMARY CIRCUIT
Fill the primary circuit following the procedure de-
tailed in the Hydro Unit Installation Manual. Vent any
trapped air by opening the air bleed point or automatic
air vent.
Ensure the water cylinder is full of water before
switching on the Air to Water heat pump System.
Switch on the electrical supply to the heat pump and
ensure the programmer is set to HOT WATER mode.
Check that any motorised valves or primary pumps
are working and allow the unit to heat.

10
FIG. 7 Thermal cut-out
6.0 MAINTENANCE
6.1 MAINTENANCE REQUIREMENTS
Unvented hot water systems have a continuing main-
tenance requirement in order to ensure safe working
and optimum performance. It is essential that the
Relief Valve(s) are periodically inspected and manu-
ally opened to ensure no blockage has occurred in
the valves or discharge pipework. Similarly cleaning
of the strainer element and replacement of the air in
the Expansion Vessel will help to prevent possible
operational faults.
The maintenance checks described below should be
performed by a competent installer on a regular basis,
e.g. annually to coincide with the air to water heat
pump maintenance.
6.2 SAFETY VALVE OPERATION
Manually operate the Temperature/Pressure Relief
Valve for a few seconds. Check water is discharged
and that it flows freely through the tundish and
discharge pipework. Check valve reseats correctly
when released. NOTE: Water discharged may be
very hot!
Repeat the above procedure for the Expansion Valve.
6.3 STRAINER
Turn off the cold water supply, air to water heat pump
system and cylinder heater. The lowest hot water tap
should then be opened to de-pressurise the system.
Remove the Pressure Reducing Valve Cartridge by
unscrewing from the housing. Pull the Reducing
Valve cartridge from the housing to access the strainer
mesh. Wash any particulate matter from the strainer
under clean water. Re-assemble ensuring the seal is
correctly tted, DO NOT use any other type of seal-
ant. Ensure the Pressure Reducing Valve Cartridge is
fully tightened.
6.4 DESCALING CYLINDER HEATER
Before removing the cylinder heater the unit must be
drained. Ensure the water and electrical supply and
air to water heat pump are OFF before draining.
Attach a hose pipe to the drain cock having sufcient
length to take water to a suitable discharge point below
the level of the unit. Open a hot tap close to the unit
and open drain cock to drain unit.
ISOLATE FROM MAINS BEFORE REMOVING
TERMINAL COVER.
Open the terminal cover. Disconnect the link wires
connecting the thermal cut-out to the cylinder heater.
Carefully remove the thermal sensor from its pocket
on the cylinder heater by pulling outwards. Care-
fully remove the thermal cut-out sensing bulb from
its pocket by pulling outwards. Remove the element
tail insulating shroud by pulling it outwards from the
element.
Unscrew the cylinder heater backnut. A key spanner
is provided with the unit for easy removal/tightening
of the backnut.
Remove the cylinder heater from the unit.
NOTE: Over time the cylinder heater gasket may
become stuck to the mating surface, to break the
seal insert a round bladed screwdriver into one of
the pockets and gently lever up and down. Carefully
remove any scale from the surface of the element. DO
NOT use a sharp implement as damage to the element
surface could be caused. Ensure sealing surfaces are
clean and seals are undamaged. If in doubt t a new
gasket.
Replace the cylinder heater ensuring the element tails
are in the vertical plane (see Fig. 6). Secure in place
by re-tting cylinder heater backnut and tightening.
Replace the element tail insulating shroud by carefully
pushing it over the element tails until it sits ush with
the face of the element mounting plate. Replace the
thermal cut-out into the left hand pocket of the cylinder
heater. Ensure it is fully inserted and that the capillary
tube is not kinked. Ensure the capillary tube is routed
such that it does not come into contact with the ele-
ment tails. Replace the thermal sensor in the left hand
pocket of the cylinder heater. Ensure it is fully inserted
behind the thermal cut-out, and the securing grommet
is pushed into the open end of the pocket.
MAINS TERMINAL
BLOCK
SENSOR TERMINAL
BLOCK
THERMAL CUT-
OUT
TERMINAL BRACKET
NOTE:
THE COVER AND ELEMENT ASSEMBLY HAVE BEEN REMOVED
FROM THIS VIEW FOR CLARITY
RESET BUTTON LOCATED
ON THIS FACE

11
Ret the cylinder heater wiring links by inserting the
male terminations into the female terminals on the ele-
ment tails in accordance to Figure 6. Check all wiring
terminations are tight and secure. Replace and secure
the terminal cover.
6.5 EXPANSION VESSEL CHARGE PRESSURE
Remove the dust cap on top of the vessel. Check the
charge pressure using a tyre pressure gauge. The pres-
sure (with system de-pressurised) should be 0.35MPa
(3.5bar). 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.
6.6 RE-COMMISSIONING
Check all electrical and plumbing connections are se-
cure. Close the drain cock. With a hot tap open, turn on
the cold water supply and allow unit to rell. DO NOT
switch on the air to water heat pump system until the
unit is full. When water ows from the hot tap allow
to ow for a short while to purge air and ush through
any disturbed particles. Close hot tap and then open
successive hot taps in system to purge any air.
When completely full and purged check system for
leaks. The air to water heat pump system can then be
switched on.
7.0 FAULT FINDING AND
SERVICING
7.1 IMPORTANT
•Servicing should only be carried by Service
Engineers or Agents or by competent installers in the
installation and maintenance of unvented water heat-
ing systems.
•Any spare parts used MUST be authorised
parts.
•Disconnect the electrical supply before removing
any electrical equipment covers.
•NEVER bypass any thermal controls or operate
system without the necessary safety valves.
•Water contained in the unit may be very hot, es-
pecially following a thermal control failure. Caution
must be taken when drawing water from the unit.
7.2 SPARE PARTS
A full range of spare parts are available for the range.
Refer to the Technical Data label on the unit to iden-
tify the model installed and ensure the correct part
is ordered.
Description
Cylinder heater 95606967
Cylinder heater gasket 95611012
Cylinder heater backnut 95607118
Cylinder heater key spanner 95607119
Tundish 95605062
Expansion valve cartridge - 6bar 95605063
Expansion valve complete - 6bar 95605064
Cold water combination valve complete 95605065
Cold water combination valve body 95605066
Check valve housing 95605067
Pressure reducing valve cartridge 3.5bar 95605068
Pressure reducing valve housing 95605069
Temperature/Pressure Relief Valve 95605070
Expansion vessel 12 litre (150 litre models) 95607127
Expansion vessel 18 litre (210 litre models) 95607128
Expansion vessel 25 litre (300 litre models) 95607129
T&P valve insulation set 95607130
Thermal sensor 95612037
Thermal cut-out (cylinder Heater) 95612038
Terminal cover 95614109
Terminal block (cylinder heater connection) 95607113
Terminal block (thermal sensor connection) 95607114
Element tail insulating shroud 95607115
Set of compression nuts and olives 95607116
Secondary re-circulation connection plug 95607117
Expansion Valve
Cartridge
Expansion Valve
Complete (6 bar)
Valve Body
Check Valve
Housing
Pressure
Reducing
Valve Housing
Pressure Reducing
Valve Cartridge
(3.5 bar)
Strainer Mesh
Housing Securing
Screws (4 off)
Cold Water Combination Valve Complete
FIG. 8 Cold Water Combination Valve - Exploded view

12
7.3 FAULT FINDING
The Fault Finding chart below will enable operational
faults to be identied and their possible causes rectied.
Any work carried out on the unvented water cylinder
and its associated controls MUST be carried out by a
competent installer for unvented water heating systems.
In case of doubt contact installer.
TABLE 5 Fault Finding Chart
WARNING
DO NOT TAMPER WITH ANY OF THE
SAFETYVALVESORCONTROLSSUPPLIED
WITH THE UNIT AS THIS WILL INVALI-
DATE ANY GUARANTEE
F A U L T P O SSIB L E C A U S E R E M E D Y
N o h o t w at e r flow 1. M ains s up p ly off 1. C he c k and turn on mains
water supply
2. Mains water filter (if
fitted) blocked .
3 . C o ld W a te r C o m b in a tion
valves fitted incorrectly.
3 . C h e c k a nd re fit as re q uire d
1. Controller on Heat Pump
Hydro Unit set to space
heating only.
1. C h ec k setting
2. Heat Pump not working 2. Check operation of Heat
Pump. If a fault is suspected
consult the Heat Pump manual.
3. Check sensor operation.
Replace if necessary.
1. Water storage temperature
on Hydro Unit controller is set
too high.
2. Turn off water supply.
Remove filter and clean in
accordance with manufacturers
instructions.
water supply.
1. Cylinder heater
thermal cut-out has
operated.
1. Check. Reset by
pushing button on cut-out.
2. Faulty water cylinder
temperature sensor.
2. Check sensor operation.
Replace if necessary.
3. Faulty water cylinder
temperature sensor
1. Check and adjust as required.
2. Faulty water cylinder
temperature sensor.
2. Check sensor operation.
Replace if necessary.
Water from hot taps is
cold
Water from hot taps is
only warm
Water from hot taps is
too hot
Water discharges from
Expansion Valve
1.INTERMITTENTLY
Expansion Vessel charge
has reduced below 0.35MPa
(3.5bar)
1. See Section 6.5 for re-
charging procedure
2. CONTINUALLY
a. Cold Water Combination
Valve Pressure Reducer
not working correctly
a. Check pressure from Cold
Water Combination Valve. If
greater than 0.35MPa (3.5bar)
replace Pressure Reducer
cartridge
b. Remove Expansion Valve
cartridge. Check condition of
seat. If necessary fit new
Expansion Valve cartridge.
b. Expansion Valve seat
damaged
Water discharges from
T&P Relief Valve
1.Thermal control failure
NOTE water will be very hot
1.Switch off power to cylinder
heater and shut down Hydro
Unit. DO NOT turn off water
supply. When discharge stops
check all thermal controls,
replace if faulty.

13
8.0 USER INSTRUCTIONS
8.1 WARNINGS
IF WATER ISSUES FROM THE TEMPERA-
TURE/PRESSURE RELIEF VALVE ON THE
UNIT SWITCH OFF ELECTRICAL SUPPLY TO
THE AIR TO WATER HEAT PUMP SYSTEM.
DO NOT TURN OFF ANY WATER SUPPLY.
CONTACT A COMPETENT INSTALLER FOR
UNVENTED WATER CYLINDERS TO CHECK
THE SYSTEM.
DO NOT TAMPER WITH ANY OF THE SAFETY
VALVES FITTED TO THE SYSTEM. IFA FAULT
IS SUSPECTED CONTACT A COMPETENT
INSTALLER.
8.2 TEMPERATURE CONTROL
The water storage temperature at the air to water heat
pump water cylinder is set at the control panel of the
Hydro Unit. This can be set to give temperatures in the
range of 40°C to 75°C, 60°C is recommended. Refer
to the Air to Water Owners Manual for details of how
to adjust the temperature if necessary.
The water cylinder is tted with an over temperature
thermal cut-out that will operate should the thermo-
static control fail.
DO NOT bypass the thermal cut-out in any cir-
cumstances.
8.3 FLOW PERFORMANCE
When initially opening hot outlets a small surge in
ow may be noticed as pressures stabilize. This is
quite normal with unvented systems. In some areas
cloudiness may be noticed in the hot water. This is
due to aeration of the water, is quite normal and will
quickly clear.
8.4 OPERATIONAL FAULTS
Operational faults and their possible causes are de-
tailed in Section 7.0. It is recommended that faults
should be checked by a competent installer.
The air volume within the expansion vessel will peri-
odically require recharging to ensure expanded water
is accommodated within the unit.A discharge of water
INTERMITTENTLY from the Expansion Valve will
indicate the air volume has reduced to a point where
it can no longer accommodate the expansion.

14
9.0 GUARANTEE
For warranty details please contact your ESTIA Heat
Pump supplier.
This product is guaranteed provided that:
• The unit has been installed in accordance with the
Installation and Service instructions and all relevant
Codes of Practice and Regulations in force at the time
of installation, and that all necessary inlet controls and
safety valves have been tted correctly.
• Any valves and controls are of the recommended
type and specication.
• It has only been used for the storage of potable
water. (Max. 250mg/l chloride)
• The unit has not been modied or tampered with
in any way, and has been regularly maintained as
detailed in the Installation and Service instructions.
• The unit has not been subjected to high chloride
levels in the water supply or incorrect disinfection
methods.
• Following commissioning the unit is put into
service within a period of 7 days. If this is not the
case it must either be drained or regularly ushed as
required in the section ‘Commissioning - Warning’.
The unit is not guaranteed against damage by frost, and
the inner container with integral cylinder heater is not
guaranteed against excessive scale build-up.
Periodic loss of charge pressure from the Expan-
sion Vessel is normal (indicated by an intermittent
discharge of water from the Expansion Valve) and
is not covered under the product guarantee. Refer to
Section 6.5 for details on how to restore the Expansion
Vessel charge pressure.
This guarantee DOES NOT cover the ESTIA Air to
Water Heat Pump Outdoor Unit or ESTIA Hydro
Unit.
This guarantee does not affect your statutory rights.
ENVIRONMENTAL INFORMATION
These products are manufactured from many recyclable
materials. At the end of their useful life they should be
disposed of at a LocalAuthority Recycling Centre in order
to realise the full environmental benets.
Insulation is by means of an approved CFC/HCFC free
polyurethane foam with an ozone depletion factor of
zero.

15
NOTES

16
Our policy is one of continuous product development and, as such, we reserve the right to change specications
without notice.
CONTACT DETAILS
TCUK Ltd
Porsham Close,
Belliver Ind.Est.
Plymouth,
Devon, PL6 7DB