Elson coral e Installation, Servicing And User Instructions Manual

Part No. 130009 Iss. 12

August 2004

Elson Coral E

Open V ented Thermal Store

providing mains pressure hot water

heated by electricity

www.elsonhotwater.co.uk

Installation, Servicing

and User's Instructions

Read these instructions thoroughly before installing the unit.

Leave these instructions with the User.

For Technical Help or Sales
queries contact 0191 4270777

COMPLIES WITH PART L BUILDING REGULATIONS

Elson is a member of the Benchmark initiative and

fully supports the aims of the programme.

Benchmark has been introduced to improve the

standards of installation and commissioning of

central heating systems in the UK and to

encourage the regular servicing of all central

heating systems to ensure safety and efficiency.

Service Helpline 08450 770087

2

Coral E

LIST OF CONTENTS

1. INTRODUCTION

The Coral E thermal store is the modern approach for the provision of electrically
heated mains pressure hot water. The unit is free from building control
requirements, can be sited anywhere in the dwelling and requires no annual
servicing. An under working surface (Coral E 100 UWS) v ersion of the 100 litre
model is available , and is suitable f or installation under a working surface with a
minimum clearance of 850 mm.

A washing machine frame (Coral E 150 or 210 WMF) v ersion is a v ailab le of the
150 and 210 litre models, the units are supplied in a white steel finish and supplied
in two packages (a special Coral E and the frame). Note a minimum clearance of
225 mm must be allowed abov e the units.

A version of the 150 litre model is available as a packaged unit (Coral E 150
EBF) to accommodate an electric boiler (not supplied). A frame is supplied
complete with fixing brackets f or the boiler. The boiler only provides space heating
via radiators, the Coral E is heated directly with its integral 3 kW immersion
heater. A sealed primary system option (Coral E 150 EBF/SS) is also available.
The unit is supplied in two pieces (a special Coral E and the frame).

Incoming mains cold water passes through a high efficiency heat exchanger coil
where it is heated by the thermal store and is distributed to all hot water outlets via
the thermostatic blending valve. The hot water and mains cold water are mixed in
the blending valve to achieve the desired temperature. The temperature can be
adjusted by the installer , as required, using the blending valv e (see section 5.2). The
blending valv e is f ail saf e in the e v ent of a mains water supply f ailure .

The unit is designed to provide maximum performance and efficiency with the
thermal store being heated overnight (via the bottom immersion heater) using
the low price 'off-peak' tariff. The top immersion heater (used for da ytime 'Boost')
is fitted directly underneath the coils allowing for fast recovery during peak
electricity periods. This 'Boost' heater is User controlled and must be operated
via a runback timer (Elson Part No. EP09101).

Both immersion heaters are factory set for maximum performance (top at 75°C
and bottom at 85°C). A User accessible manual reset safety thermostat is
connected to the bottom (overnight) heater switching it off in the unlikely e vent of
an overheat situation.

Heat loss from the thermal store is minimised by the use of a 50 mm thick HCFC
free polyurethane injected foam insulation.

Water lost from the thermal store by evaporation is replaced via the feed and
expansion tank fitted within the unit.

The standard Coral E is available in either white metal finish or hardboard and
is delivered in a single package of the following sizes:- (100 litre model - 960 x
520 x 650 mm, weighing 40 kg), (100 UWS model - 845 x 610 x 650 mm,
weighing 40 kg), (150 litre model - 1400 x 525 x 650 mm, weighing 60 kg),
(210 litre model - 1400 x 610 x 650 mm, weighing 66 kg).

For Service queries contact our Service Helpline on 08450 770087. For Technical
Help or Sales queries contact 0191 4270777.

1. Introduction ....................................................P a ge 2

2. Important Notes....................................................... 2

3. T echnical Data ......................................................... 3

4. Installation ............................................................... 4

5. Commissioning ....................................................... 5

6. Servicing/replacement of parts .............................. 6

7. Spare Parts List ....................................................... 7

8. Wiring Diagrams...................................................... 7

9. Fault Finding............................................................ 7

10. User's Instructions .................................................. 8

Typical Coral E WMF

installation

Coral E EBF/SS

3

Coral E

3. TECHNICAL DATA

Connections

* Frame size (mm) of WMF models is 730 wide, 660 deep and 915 high.

Frame size (mm) of 150 EBF/SS model is 600 wide, 600 deep and 1080 high.
Frame size (mm) of 210 EBF/SS model is 650 wide, 650 deep and 1080 high. All frame weights are approximately 14 kg.

Heat loss exceeds the requirements of BS 3198.

Notes:

i. Allow a minimum of 100 mm on the depth to accommodate the immersion heater covers and plumbing connections .
ii. All models are supplied fitted with two 3 kW Maxistore immersion heaters. The 100 and 150 models can be

supplied with only one immersion heater (bottom) fitted with the other boss plugged, if specified when ordered.
iii.Dimensions shown are for the hardboard cased v ersions , the white metal cased units are slightly smaller.
iv.All compression fittings are suitable to accept copper tubing to EN 1057.

Graph giving an indication of the minimum hot water performance available

Figures obtained using the store fully
heated to 85°C, with a mains cold water
supply temperature of 10°C and the
following constant draw off rates:-

Coral E 210 - 18 litres/min.
Coral E 150 - 18 litres/min.
Coral E 100 - 12 litres/min.

Volume drawn off (litres)

8020 260 280 30022020040 18014012060 100 160 240

50

45

Temp

(°C)

40

Coral E 210
Coral E 150
Coral E 100

3.1.Hot water performance

Electricity supply:

230/240 V ~ 50 Hz
(each heater fused at 13 A)

2. IMPORTANT NOTES

1. The control thermostats on both immersion heaters are factory set for maximum performance (top at 75°C

and bottom at 85°C). The bottom thermostat may be reduced slightly (not belo w 75°C) where it is known that
hot water demand will not be high.

2. The top ('Boost') immersion heater must be controlled via a runback timer (one or two hours, pref erab ly one
hour) and not a simple isolating switch. This timer has two purposes, firstly to prev ent uneconomical use of full
price electricity and secondly it acts as a form of protection against long periods of boiling in the unlikely event
of thermostat failure, therefore pre v enting permanent damage to the unit.

Note: If a runback timer is not fitted and the unit is damaged due to boiling, the damage will not be
covered by the pr oduct guarantee.

3. For optimum perf ormance we recommend a dedicated 22 mm mains cold water supply to the unit and a 15 mm hot

water outlet. If the mains cold water supply pressure is less than 1 bar w e recommend a 22 mm hot water outlet.

4. The level of the water in the f eed and expansion tank must be set to the w aterline mark - it is not factory set.

5. An isolating valve should be fitted in the mains cold water supply to the unit.

6. We recommend that a Y type line strainer is fitted in the mains cold water supply to the unit.

7. We recommend that a scale reducer is fitted on the mains cold water supply prior to the unit. This is especially

important in hard water areas (in-line scale reducers may reduce flow rates).

8. If a non-return valve is fitted in the mains cold water supply to the unit, provision must be made to accommodate
the increased water volume during the normal heat-up cycle, e.g. a mini expansion vessel with a capacity of
not less than 160 ml (i.e. Zilmet Z160).

9. The hot water blending valve is factory set to approximately 50°C. For adjustment refer to section 5.2.

10. For installation and servicing requirements, the portion of the work surface above the UWS model must be

removable. The unit may be positioned in a cupboard space beneath the work surface and a door fitted, if
required - allow 100 mm on the depth to accommodate the immersion heater covers and plumbing connections .

100 UWS
100
150
210
300

* 150 EBF/SS
* 210 EBF/SS
* 150 WMF
* 210 WMF

100
100
150
210
300
150
210
150
210

571
571
571
571
600
600
650
560
571

750

865
1285
1285
1285

880

940

820
1000

571
495
495
584
700
600
650
730
730

Tank height

mm

Capacity

litres

Tank depth

mm

Heat loss to BS 3198

W/litre (kW/24hrs)

0.44 (1.18)

0.44 (1.18)

0.33 (1.28)

0.27 (1.48)

0.33 (1.28)

0.27 (1.48)

0.33 (1.28)

0.27 (1.48)

Tank width

mm

Coral E

model

Hot water 15 mm comp.
Mains cold water 22 mm comp.
Overflow 22 mm comp.
Immersion heater 2¼" BSP (2 off)
Drain boss ½" BSP

-

-

-

-

­1960
2020
1735
1915

Total height

with frame mm

4

Coral E

4. INSTALLATION

4.1.Position the unit and make the water connections

Refer to Fig. 2 for the recommended route of the pipew ork to the unit.

1. You will find a lid in the feed and expansion tank.

2. Place the unit in position. Ensure that the face of the unit with the immersion heaters is to the front.

3. Connect the mains cold water supply to the unit. See Fig. 2. Ensure that an isolating valve and a Y type line
strainer are fitted just before the unit.

In hard water areas it is recommended that a scale reducer is fitted in the mains cold water supply to the unit.

4. Connect a suitable overflo w system to the overflow fitting. See Fig. 2. Copper tubing is recommended.

5. Connect the domestic hot water draw-off pipework to the b lending v alve.

6. Fit a drain cock to the ½" BSP boss on the front of the unit.

Notes:

i. For optimum performance we recommend a dedicated 22 mm mains cold water supply to the unit and a 15

mm hot water outlet. If the mains cold water supply pressure is less than 1 bar w e recommend a 22 mm hot

water outlet.
ii. The mains cold water supply should be flushed bef ore connecting it to the unit.
iii.Adequate clearance must be allowed for the pipe runs to the unit. From an appearance point of view and for

reduced heat loss from pipework we recommend that the pipework is run up the rear of the unit if possible .
iv .The overflow connection may be tak en from the right hand or the rear of the unit. Copper tube recommended.

4.2.Electrical connection

Refer to wiring diagrams in section 8.

All electrical wiring must be carried out by a qualified electrician, and must be in accordance with BS 7671 ­Regulations for Electrical Installations, IEE Wiring Regulations and any local regulations which apply.

The mains supply required is 230/240 V ~ 50 Hz (each heater fused at 13 A).
Ensure the electricity supply has been isolated.
The immersion heaters must be connected using 85°C heat resistant rubber insulated HOFR sheathed flexible

cord 1.5 mm².
A double pole isolating switch with a contact separation of at least 3 mm in each pole must be incorporated in each supply.

3.2.Clearances

A minimum 10 mm is required at each side (additional access
for the wiring is required at the right hand side, see Fig. 2).
225 mm is required above the unit for ball v alve replacement.

Full frontal access must be available for installation and
removal/replacement of components.

Allow a minimum of 100 mm on the depth to accommodate
the immersion heater covers and plumbing connections.

Adequate clearance must be allowed for water and overflow
connections. Refer to section 4.1 for further details.

750

100 mm

clearance for

blending valve

Removable work surface

CORAL E

Fig. 1 - Coral E 100 UWS

Fig. 2

Side entry
points for wiring
(RH side only)

Alternative
overflow
connection

Feed and
expansion
tank

Overflow

Overflow
connection
access plate

Mains cold

water *

Hot

water *

Blending valve

* Hot and cold

pipework may
also be run to the
unit from above
or left/right hand
sides.

'Boost'

immersion

heater

User

accessible

overheat limit

thermostat

'Overnight'
immersion

heater

Drain boss

5

Coral E

The heaters must be controlled by two independent, protected and switched circuits . The bottom heater should be
switched to operate during the off-peak period(s) of the tariff only via a suitable controller, e.g. Maxistore. The
circuit to the upper heater must include a runback timer (one or two hours, preferably one hour) and not a simple
isolating switch. This timer has two purposes, firstly to prevent uneconomical use of full price electricity and secondly
it acts as a form of protection against long periods of boiling in the unlikely event of thermostat failure, therefore
preventing permanent damage to the unit.

Failure to fit a suitable timer will in validate the guarantee.

1. Remove the plastic cov ers from the immersion heaters - F our screws on the bottom heater , top heater co v er

¼ turn anticlockwise.

2. Remove the plastic cover from the top immersion heater - one nut.

3. Connect the immersion heaters to the controllers using the correct cable as described above. Route the

cables through the RH side entry points as shown in Fig. 2.

4. Replace the wiring covers, ensuring all wiring is secured using the cable clamps provided.

Important Notes:

i. The unit must be earthed.
ii. Check that the immersion heater control thermostats are correctl y set f or maxim um perf ormance (top

at 75°C and bottom at 85°C). The bottom thermostat may be reduced slightly (not below 75°C) where it is
known that hot water demand will not be high.

iii.Do not switch on the electricity supply before the unit has been filled with water.

4.3.Fill the system

1. Having completed the system pipework, turn on the mains water supply and the thermal store will fill with

water via the internal feed and expansion tank.

2. Vent the hot water pipework b y opening a hot tap.

3. Check the immersion heaters and all connections for water soundness, rectifying where necessary.

4. Check the water lev el in the f eed and e xpansion tank is to the marked w ater line. If necessary adjust the float

operated ball valv e. Fit the plastic lid on the tank.

5. COMMISSIONING

5.1 Appliance commissioning

1. Check that the electric circuits are tested in accordance with the IEE wiring regulations and that the system is

operating satisfactorily in terms of the proper functioning of all the components and their controls.

2. The unit should be fully heated to ensure the thermostats of both the immersion heaters are operating correctly .

5.2 Blending valve

The blending valv e is factory set to approximately 50°C.
The blending valv e has an output temperature range from 35° to 55°C . If it is necessary to adjust the temperature

proceed as follows:-

1. Locate the nearest outlet being supplied by

the valve .

2. Open the outlet to allow a flow rate of at least

4 litres/min.

3. Allow the water to run for at least one minute

to ensure the mixed water temperature has
settled.

4. Using a thermometer, check the mixed w ater

temperature.
Has the desired temperature been

achieved?

Yes - go to paragraph 7
No - go to paragraph 5

5. Adjust the valve as sho wn in Fig 3 (using the adjusting key supplied) until the desired mix ed outlet temperature

is achieved.

6. Repeat paragraphs 1 - 4.

7. Replace the valve cap and close the outlet.
A record of the commissioning settings should be made for comparison with future maintenance checks.

Tur n anti-clockwise to
increase temperature

Fig. 3

Tur n clockwise to

reduce temperature

Cap

6

Coral E

5.3 Hand over the system

1. The system can now be handed over to the User, who should be given this instruction booklet.

2. Clear verbal instructions should be given to the User on how to operate the unit and specific controls, with
particular reference to the User's instructions given in section 10.

3. Complete the installation details on the back page of this booklet.

6. SERVICING

If the unit is installed in a hard water area and is suffering from scaling problems, contact the Elson Technical
Helpline on 0191 4270777 for information on descaling.

6.1.Maintaining the blending valve

If the temperature of the water at the hot taps has become
too hot or cold, the blending valv e may require cleaning.

Clean the blending valve as follo ws:-

1. Isolate the hot and cold supplies and remove the
valve body from the unit b y undoing the adaptor
union nuts. Make a note of the orientation of the
parts as they are removed so that the can be re­assembled in the correct manner. See Fig. 4.

2. To clean the inter nals of the main valve body, first
remove the cap and then carefully remove the valve
headwork by unscrewing the large he x nut.

3. Slide the piston and thermostat assembly out of the
valve body and clean all internal surfaces and 'O' rings
with a weak solution of scale remover or (vinegar)
approved f or use with potab le w ater.

4. Using a WRAS approved silicone based waterproof
grease, lightly lubricate the 'O' ring in the body and
the external surface of the piston.

5. After cleaning, re-assemble the valve and re-set the
temperature as described in section 5.2.

6.2 To replace the overheat limit thermostat

1. Switch off the electricity supply to the unit.

2. Remove the four scre ws securing the low er immersion heater co ver and lift off the cover.

3. Disconnect the two leads from the thermostat, positioned above the immersion heater and remove the two
fixings securing the thermostat. Take care not to lose the spacers behind the thermostat.

4. Fit the replacement thermostat (ensuring the spacers are in position on the fixing screws behind the thermostat)
securing it in position with the fixings previously removed and reconnect the leads (polarity is not important).
Check that thermostat reset button is depressed.

5. Replace the immersion heater cover and secure with f our scre ws .

6.3 To replace an immersion heater

Both immersion heaters are the same, but the wiring is different. Refer to the wiring diagrams for the correct
connections.

1. Switch off the electricity supply to the unit.

2. Turn off the water supply and drain the unit.

3. Remove the plastic cov er from the immersion heater - Four screws on the bottom heater, top heater cover ¼
turn anticlockwise.

4. Top heater only:- Remove the plastic cover from the immersion heater - one nut.

5. Disconnect the wiring from the heater and unscrew it from the unit.

6. Fit a new heater , using the new rubber gasket supplied with the replacement heater , and reconnect the wiring.
See wiring diagram.

Note: PTFE tape or thread sealant must not be used when fitting a replacement immersion heater.

Temper ature adjuster key
and cap
SKIT 160 300
(kit also contains adjusting
key)

Full internal service kit
SKIT 160 302

Seal service kit
SKIT 160 301

Fig. 4

7

Coral E

9. FAULT FINDING

8. WIRING DIA GRAMS

8.1 Upper immersion heater

8.2 Lower immersion heater

Note: The mains supply to the upper heater must be via

a suitable controller which will not allow the heater to be
left on continuously. See Important Note 2 on page 3.

Item

Limit thermostat ................................................... 10010002

Control thermostat ............................................... EP051016

Standard immersion heater - complete (2 off)...... 90100001

Blending valve - complete.................................... EP100071

Runback timer ..................................................... EP09101

Part No.

7. SPARE PARTS LIST

The following specialist spare parts for the Coral E are readily a v ailable from Elsy & Gibbons Limited:-

7. Check that the control thermostat setting is correct for maximum perf ormance (top at 75°C and bottom
at 85°C). The bottom thermostat may hav e been reduced slightly (not belo w 75°C) where it is known that hot
water demand will not be high.

8. Replace the covers.

In accordance with our policy of continual product improvement, we
reserve the right to amend the specification of these products without
prior notification.

© Elsy & Gibbons Limited 2004.
All rights reserved. No part of this manual may be reproduced by any
means without prior written consent.

Manual compiled and designed by Publications 2000. Tel [phone]

08/04/D64

Elsy & Gibbons,

Simonside
South Shields,
Tyne and W ear NE34 9PE

Telephone: [phone]
Facsimile: 0191 427 0888

www.elsonhotwater.co.uk

TO BE COMPLETED BY THE INSTALLER

1. Product serial No............................................................................................................

2. Installation date ..............................................................................................................

3. Name of Installer ............................................................................................................

Address ..........................................................................................................................

........................................................................................................................................

........................................................................................................................................

Telephone No..................................................................................................................

4. Type of controller fitted ...................................................................................................

5. Details of supply tariff .....................................................................................................

6. Is a scale reducer fitted? Yes/No Details.........................................................

7. Is a Y type line strainer fitted? Yes/No Details.........................................................

10. ELSON CORAL E USER'S INSTRUCTIONS

1. Your hot water system is designed to provide mains pressure hot water to all outlets including showers,
turning an ordinary shower unit into a 'Power Shower' without the need for expensiv e pumps .

2. The temperature of the hot water supplied to your taps can be adjusted from 35° to 55°C by adjusting the
blending valv e on the top of the unit. See section 5.2 on page 5. The temperature is factory set to approximately
50°C.

3. The Coral E is designed to make the most of low price off-peak electricity, you should contact your electricity
supplier, asking for details of your particular supply and advice for economical use.

4. For the most economical use of the Coral E y ou should restrict your main use of hot water (baths etc.) to such
a time that the water in the unit will be re-heated during the off-peak period.

5. IMPORTANT: The 'Boost' immersion heater fitted to the Coral E operates on full price electricity, it should
therefore be used sparingly and always switched off after use. A runback timer should have been fitted when
the unit was installed.

6. The Coral E is fitted with a safety ov erheat limit thermostat, see Fig. 2, which will automatically switch off the
'Overnight' immersion heater in the case of a control thermostat malfunction causing overheating. If y ou find
the tank is cold in the morning, press the reset button (use the end of a pen or pencil) on the limit thermostat
to reset it and the tank should be reheated overnight as normal. If y ou require hot water sooner , use the 'Boost'
immersion heater to heat the water (see note 5 above).

If the limit thermostat needs to be continually reset, contact your Installer.

7. When running a bath, you can increase the temperature and volume of water b y reducing the flow rate at the
tap, i.e. do not open it fully.

8. When cleaning the Coral E do not use abrasive cleaners on the white metal cased models or wet cloths on the
hardboard cased models.