Santon PP250E, PP300E, PP100B, PP120B, PP150B Installation And Servicing Instructions

1

UNVENTED MAINS PRESSURE WATER HEATER

100, 120, 150, 170, 210, 250 AND 300 LITRE

DIRECT AND INDIRECT MODELS

INSTALLATION AND SERVICING INSTRUCTIONS

36 00 5803 Issue 7

PACK CONTENTS

Premier Plus unvented water heater incorporating immersion heater(s) and thermal controls

Factory tted Temperature/Pressure Relief Valve Cold Water Combination Valve Expansion
Vessel Expansion Vessel Mounting Bracket Tundish Motorised Valve (Indirect models
only) Compression nuts and olives Immersion heater spanner Installation Instructions

2

SANTON PREMIER PLUS INSTALLATION AND SERVICING INSTRUCTIONS.

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 - DIRECT UNITS . . . . . . 9

5 INSTALLATION – INDIRECT UNITS . . . . . 9

6 COMMISSIONING . . . . . . . 11

7 MAINTENANCE . . . . . . . 12

8 FAULT FINDING AND SERVICING . . . . . 13

9 USER INSTRUCTIONS . . . . . . 15

10 GUARANTEE . . . . . . . . 16

11 SPARES STOCKISTS . . . . . . . 16

1.0 INTRODUCTION

The Santon Premier Plus is a purpose designed
unvented water heater. The unit has a stainless steel
inner vessel which ensures an excellent standard of
corrosion resistance. The outer casing is a combina­tion of resilient thermoplastic mouldings and plastic
coated corrosion proofed steel sheet. All Premiers
are insulated with CFC free polyurethane foam to

meet the latest European heat loss requirements (see

Table 3).

The unit is supplied complete with all the necessary
safety and control devices needed to allow connec­tion to the cold water mains. All these components

are pre-adjusted.

NOTE: Prior to installation the unit should be stored

in an upright position in an area free from excessive

damp or humidity.

This appliance complies with the requirements of
the CE marking directive and is WRAS approved to
show compliance with Building Regulations (Sec­tion G3).

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 1990, or The Building Regula-

IMPORTANT: PLEASE READ ALL THESE INSTRUCTIONS BEFORE
COMMENCING INSTALLATION

TABLE 1: OPERATIONAL SUMMARY

Maximum water supply pressure to PRV 16.0 bar
Operating pressure of unit 3.5 bar
Expansion vessel charge pressure 3.5 bar
Expansion valve setting 6.0 bar
Nominal storage capacity of units (see Section 2 Table 2)
Max. primary working pressure 3.0 bar (indirects only)
Opening temperature of T&P Relief Valve 90deg C
Opening pressure of T&P Relief Valve 10 bar

3

2.0 GENERAL REQUIREMENTS

2.1 COMPONENTS SUPPLIED

1. Premier Plus unvented water heater incorporating
immersion heater(s) and thermal controls

2. Factory tted Temperature/Pressure Relief Valve

3. Cold Water Combination Valve.

4. Expansion Vessel and mounting bracket.

5. Tundish.

6. Motorized Valve (Indirect models only).

7. Compression nuts and olives

8. Immersion heater key spanner

2.2 SITING THE UNIT

The Santon Premier Plus must be installed vertically.
Although location is not critical, the following points

should be considered:

• The Santon Premier Plus 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 immersion

heaters should be possible to allow for periodic servic-

ing and maintenance.

• Ensure that the base chosen for the Santon

Premier Plus 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 owrates.

Wherever possible the mains supply pipe should be
22mm. We suggest the minimum supply requirements

should be 1.5 bar pressure and 20 litres per minute
owrate. However, at these values outlet owrates
may be poor if several outlets are used simultane­ously. The higher the available pressure and owrate
the better the system performance.
The Santon Premier Plus has an operating pressure of

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 16 bar.

2.4 OUTLET/TERMINAL FITTINGS (TAPS, ETC.)

The Santon Premier Plus can be used with most
types of terminal ttings. 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 Premier Plus water
heater. Outlets situated higher than the Santon Premier

Plus will give outlet pressures lower than that at the

heater, a 10m height difference will result in a 1 bar

pressure reduction at the outlet.

2.5 LIMITATIONS

The Premier Plus unvented water heater should not be
used in association with any of the following:

• Solid fuel boilers or any other boiler in which the

energy input is not under effective thermostatic control
unless additional and appropriate safety measures are

installed.

• Ascending spray type bidets or any other class 1

back syphonage risk requiring that a type A air gap

be employed.

• Steam heating plants unless additional and ap-

propriate safety devices are installed.

• 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

Type Model

reference

Nominal

capac ity

(litres )

W eight of

unit full

(kg)

DIRECT PP100E 100 123

PP120E 120 145
PP150E 150 178
PP170E 170 199
PP210E 210 246
PP250E 250 295
PP300E 300 355

INDIRECT PP100B 100 125

PP120B 120 147
PP150B 150 181
PP170B 170 203
PP210B 210 251
PP250B 250 300
PP300B 300 360

Nom ina l

ca pa ci ty per da y pe r ye a r

(litres ) (kW h/ 24h) (kW h/365d)

100 1.14 416 . 1
120 1.25 456 . 3
150 1.45 529 . 3
170 1.63

595.0
210 1.91 697.2
250 2.22 810.3
300 2.52 919.8

Sta nding He a t Loss

4

SECONDARY�

RETURN

COLD�

SUPPLY

CHECK�

VA LV E

SECONDARY�

CIRCULATION�

PUMP

COLD�

INLET �

CONNECTION

SWEPT�

TEE

3.0 INSTALLATION – GENERAL
(FIGS 3 & 5)

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 Santon Pre-

mier Plus 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 Com­bination 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 Premier Plus 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 Premier Plus unit between the

Cold Water Combination Valve and the heater 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 heater (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 3.5 bar. The Expansion Vessel must

be connected between the Cold Water Combination

Valve and the Santon Premier Plus (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 Premier as shown in Fig.

2 via a swept tee joint into the cold feed to the unit.
A Swept Tee joint is available as an accessory order
code no. 94 970 033.
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)
Secondary circulation is NOT recommended for di­rect electric units being used on Off Peak electricity
tariffs.

3.7 OUTLET

The hot water outlet is a 22mm compression tting
located at the top of the cylinder. Hot water distribu­tion 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)

5

A B C D

SURFACE

A

REA

(sq.m)

RATING

(kW)

RECOVERY

(mins)

99487394603E001

100 B 315 354 493 784 0.43 11.8 18

121609516603E021

120 B 315 354 615 906 0.43 12.5 22

2510901008603E051

150 B 315 354 800 1090 0.55 16.4 21

3716121529603E071

170 B 315 354 925 1216 0.61 16.0 24

51247414811603E012

210 B 315 354 1184 1474 0.68 18.3 26

75262711931603E052

250 B 315 354 1391 1726 0.79 20.0 27

01304025171603E003

300 B 315 354 1715 2040 0.79 20.0 33

NOTES:

1. Recovery time based on heating 70% of capacity through 45 deg. C

2. Direct heating tim

es assume use of lower element only

HEATING

TIME

DIRECT

(mins)

TYPE DIMENSIONS (mm) COIL

NOMINAL

CAPACITY

(litres)

E = DIRECT

B = INDIRECT

FIG. 3 General Dimensions

Test results obtained by WRc-NSF in accordance with Test Criteria 1-50-220 and 1-50-222

M ode l Heatin g tim e

15 to 65d e g . C

70% Re co v e ry

tim e

Note s

tupni Wk3snim71 ruoh1snim80 sruoh2E001PP
P P 150E 1hour 33m ins 1hour 08m ins 6k W input (us ing b o th im mers ion heaters )
P P 210E 2hours 2 1 m ins 1hour 51m ins 6 k W input (u s ing both im m ers ion heat e rs )

P P 100B 21m ins 15m ins Indirec t ly heat e d . P rim ary flow 82deg. C at 15l/m in
P P 150B 24m ins 20m ins Indirec t ly heat e d . P rim ary flow 82deg. C at 15l/m in
P P 210B 32m ins 29m ins Indirec t ly heat e d . P rim ary flow 82deg. C at 15l/m in

6

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 tempera­ture 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 calcu­late 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 require­ments 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 Build­ing Control Ofcer or Santon.

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 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 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 vis­ibility 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 dwell­ings 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. Se e Building
Regula tion 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 Guid­ance section 3.9)

Valve outl e t siz e M inim um siz e of

discha rge pipe

D1

Minim um siz e of

discha rge pip e

D2 from tundish

Maxim um

re sistance

allow ed,

expresse d a s a

le ngth of straight

pipe (I.e . no

elbow s or be nds)

Re sistance

create d by each

elbow or be nd

G1/2 15m m

22mm
28mm
35mm

up to 9m
up to 18m
up to 27m

0.8m

1.0m

1.4m

G3/4 22m m

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 fitted

Temperature/Pressure Relief Valve be removed other
than by authorised Santon personnel. To do so will
invalidate any guarantee or claim.

• The Cold Water Combination Valve must be fitted

to the mains water supply to the Premier Plus 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

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

BOOST ELEMENT /

CONTROL HOUSING

(PP120E TO PP300E

MODELS ONLY)

NOTE: PRIMARY HEATING COIL
FITTED ON PP100B TO PP300B

MODELS ONLY

SECONDARY

RETURN

TAPPING (IF

REQUIRED)

BALANCED
COLD WATER
CONNECTION

(IF REQUIRED)

FIG. 5 Typical installation - schematic

FIG. 6 Electrical Connections (Schematic)

B

R

O

W

N

B

L

U

E

G

R

E

E

N

/

Y

E

L

L

O

W

SLEDOM TCERIDNISLEDOM TCERID

Note: On models fitted with two or three elements each element must be
wired individually in accordance with the diagram above.

THERMOSTAT

EARTH
CONNECTION

FUSED (13A) DOUBLE
POLE ISOLATING
SWITCH

A

B

1.5mm

2

3 CORE
HOFR SHEATHED
CABLE

1

2

GREEN/YELLOW

13 AMP MAINS

SUPPLY. 1.5mm

2

MIN. CABLE SIZE

TO INDIRECT SYSTEM

CONTROLS JUNCTION

BOX - SEE FIGS. 7/8

GREEN/

YELLOW

BROWN

BLUE

3

DIRECT THERMOSTAT

B

A

112

2

3

INDIRECT THERMOSTAT

INDIRECT THERMAL CUT-OUT

9

4.0 INSTALLATION - DIRECT
UNITS

4.1 PLUMBING CONNECTIONS

Direct units require 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.

4.2 ELECTRICAL SUPPLY (FIG. 6)

100 litre direct Premier Plus units are tted with one
3kW immersion heater, all other direct models are
tted with two 3kW immersion heaters as standard.
It is recommended that these should be wired via a
suitable controller to BSEN 60730. The Premier Plus
MUST be earthed. The 250 and 300 litre units have
an additional boss which has a blanking plug tted.
An additional immersion heater can be tted in place
of the blanking plug where a higher electrical input
is required for faster recovery times, order Part No.
95 970 510 if required.
All wiring to the unit must be installed in accordance
with the latest IEE Wiring Regulations and the circuit
must be protected by a suitable fuse and double pole
isolating switch with a contact separation of at least
3mm in both poles. The Live and Neutral connections

are made directly onto the combined thermostat and
thermal cut-out located under the terminal cover(s)
mounted on the side of the unit. The Earth connec­tion should be made to the earth connection located to

the side of the immersion heater boss(es). The supply

cable must be routed through the cable gland located
on the unit casing beneath the terminal housing.

DO NOT operate the immersion heaters until the San-

ton Premier Plus has been lled with water.

4.3 SAFETY
DISCONNECT FROM THE MAINS SUPPLY
BEFORE REMOVING ANY COVERS.

Never attempt to replace the immersion heater(s)

other than with the recommended Santon immersion

heater(s).

DO NOT BYPASS THE THERMAL CUT-OUT(S)
IN ANY CIRCUMSTANCES. Ensure the two male

spade terminations on the underside of the combined
thermostat and thermal cut-out are pushed rmly onto

the corresponding terminations on the element plate
assembly.

In case of difficulty contact Santon service, tel:

5.0 INSTALLATION - INDIRECT

UNITS

5.1 PLUMBING CONNECTIONS

Indirect units require 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.

Primary connections are 22mm compression. How­ever, 3/4”BSP parallel threaded ttings can be tted
to the primary coil connections if required.

5.2 ELECTRICAL SUPPLY (FIG. 6)

All Indirect units are tted with a 3kW immersion

heater and a combined thermostat and thermal cut-out
to control the indirect heating source. The Premier

Plus MUST be earthed.

All wiring to the unit must be installed in accordance
with the latest IEE Wiring Regulations and the supply
circuits must be protected by a suitable fuse and double
pole isolating switch with a contact separation of at
least 3mm in both poles. All connections are made to
the terminal block located under the terminal cover
mounted on the side of the unit. The supply cable(s)

must be routed through the cable grip(s) in the termi­nal housing.

DISCONNECT FROM MAINS SUPPLY BE­FORE REMOVING ANY COVERS. DO NOT
BYPASS THE THERMAL CUT-OUTS IN ANY
CIRCUMSTANCES. Ensure the thermostat and

thermal cut-out sensing bulbs are pushed fully into
the pockets on the element plate assembly.

5.3 BOILER SELECTION

The boiler should have a control thermostat and non
self-resetting thermal cut-out and be compatible with

unvented storage water heaters.

Where use of a boiler without a thermal cut-out is
unavoidable a “low head” open vented primary circuit
should be used. The Feed and Expansion cistern head

above the Premier Plus should not exceed 2.5m.

5.4 PRIMARY CIRCUIT CONTROL

The 2 port motorised valve supplied with the Premier
Plus indirect units MUST be tted to the primary ow

to the Premier Plus heat exchanger and wired in series

with the indirect thermostat and thermal cut-out tted

to the unit.
Primary circulation to the Premier Plus heat exchanger

must be pumped, gravity circulation WILL NOT
WORK.

5.5 SPACE AND HEATING SYSTEMS CONTROLS

The controls provided with the Santon Premier Plus
will ensure the safe operation of the unit within a

central heating system. Other controls will be neces­sary to control the space heating requirements and

times that the system is required to function (see
Fig. 7). The Santon Premier Plus is compatible with
most heating controls, examples of electrical circuits
are shown in Figs. 7 and 8. However, other systems
may be suitable, refer to the controls manufacturers’
instructions, supplied with the controls selected, for

alternative system wiring schemes.

10

PROGRAMMER

PMUPRELIOB

ROOM STAT

ZONE VALVE(DHW)

(SUPPLIED)

ZONE VALVE (HTG)

PREMIER PLUS

TERMINAL BLOCK

JUNCTION BOX

123456789 10

123456789 10

L NL N

G

Br Bl O

GY

G Br Bl O

GY

1

3 2

L

N

2

3

HTG DHW
ON

ON

221 3 123

321

2 3

2

3

L N

(SUPPLY)

1

3

Control terminal numbering may
differ from those shown. Refer to
instructions with controls

selected

A DOUBLE POLE ISOLATING
SWITCH MUST BE INSTALLED
IN THE MAINS SUPPLY.
ALL EARTH CONNECTIONS
BE CONNECTED BACK TO
THE MAINS EARTH SUPPLY

FIG. 7 Schematic wiring diagram - Basic 2 x 2 port valve system

FIG. 8 Schematic wiring diagram - 3 port mid position valve system. N.B. Must be used in
conjunction with 2 port zone valve suuplied

PROGRAMMER

BOILER

PUMP

ROOM STAT

ZONE VALVE(DHW)

(SUPPLIED)

ZONE VALVE (HTG)

PREMIER PLUS

TERMINAL BLOCK

JUNCTION BOX

123456789 10

123456789 10

L N

G Br Bl O

GY

G

W

Bl O

GY

132

L

N

2

3

2

2

3 123

2 3

2

3

L N

(SUPPLY)

1

3

L N

HTG DHW

ON

ON

1 2 3

DHW

OFF

Control terminal numbering may
differ from those shown. Refer to
instructions with controls

selected

A DOUBLE POLE ISOLATING
SWITCH MUST BE INSTALLED
IN THE MAINS SUPPLY.
ALL EARTH CONNECTIONS
BE CONNECTED BACK TO
THE MAINS EARTH SUPPLY

11

6.0 COMMISSIONING

6.1 FILLING THE UNIT WITH WATER

• Check Expansion Vessel pre-charge pressure. The

vessel is supplied pre-charged to 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

immersion heater(s). An immersion heater key spanner
is supplied for this purpose.

• Ensure the drain cock is CLOSED.

• Open a hot tap furthest from the Santon Premier

Plus.

• Open the mains stop cock to ll the unit. When

water ows from the tap, allow to run for a few min­utes to thoroughly ush through any residue, dirt or
swarf, then close the tap.

• Open successive hot taps to purge the system of

air.

6.2 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.

6.3 DIRECT UNITS

Switch on electrical supply to the immersion heater(s)
and allow the Premier Plus to heat up to normal work­ing temperature (60ºC recommended, approximately
graduation 4 on the thermostat). If necessary the
temperature can be adjusted by inserting a at bladed
screwdriver in the adjustment knob on top of the im­mersion heater thermostat and rotating. The adjust­ment range 1 to 5 represents a temperature range of
10o to 70oC. Check the operation of thermostat(s) and
that no water has issued from the Expansion Relief
Valve or Temperature/Pressure Relief Valve during

the heating cycle.

6.4 INDIRECT UNITS

Fill the indirect (primary) circuit following the boiler
manufacturer’s commissioning instructions. To ensure
the Premier Plus primary heat exchanger is lled, the

2 port motorised valve (supplied) should be manually
opened by moving the lever on the motor housing to

the FLUSHING ONLY setting. When the primary
circuit is full return the lever to the NORMAL USE
position. Switch on the boiler, ensure the programmer
is set to Domestic Hot Water and allow the Premier
Plus to heat up to a normal working temperature

FIG. 9 Indirect thermostat and thermal cut-
out

(60oC recommended, approximately graduation 4
on the thermostat). If necessary the temperature can
be adjusted by inserting a at bladed screwdriver in
the adjustment knob (located on top of the thermo­stat mounting bracket - see Fig.9) and rotating. The
minimum thermostat setting is 10oC. The adjustment
range 1 to 5 represents a temperature range of 30o to
70oC. Check the operation of the indirect thermostat

and 2 port motorised valve and that no water has is-

sued from the Expansion Relief Valve or Temperature/
PressureRelief Valve during the heating cycle.

6.5 BENCHMARKTM LOG BOOK

On completion of the installation and commissioning
of the Premier Plus the BenchmarkTM “Installation,
Commissioning and Service Record Log Book”
should be completed and signed off by the competent

installer or commissioning engineer in the relevant
sections.

The various system features, location of system con­trols, user instructions and what to do in the event of
a system failure should be explained to the customer.
The customer should then countersign the Bench­markTM log book to accept completion.
The log book should be left with the customer along
with these instructions. The log book includes sections
that should be lled out when any subsequent service

or maintenance operation is carried out on the Premier
Plus system.

CABLE CLAMPS

TERMINAL BLOCK

INDIRECT
THERMOSTAT

THERMOSTAT
ADJUSTMENT

INDIRECT
THERMAL
CUT-OUT

INDIRECT THERMAL
CUT-OUT RESET
BUTTON

NOTE:
THE HOUSING COVER AND ELEMENT ASSEMBLY
HAVE BEEN REMOVED FROM THIS VIEW FOR
CLARITY

12

Carefully remove any scale from the surface of the
element(s). DO NOT use a sharp implement as dam­age to the element surface could be caused. Ensure
sealing surfaces are clean and seals are undamaged,
if in doubt t a new gasket.

Replace immersion heater(s) ensuring the lower (right

angled) element hangs vertically downwards towards

the base of the unit. It may be helpful to support the

immersion heater using a round bladed screwdriver

inserted into one of the thermostat pockets whilst
the backnut is tightened. Replace thermostat (Direct
models) or thermostat capillaries into pocket (Indirect
models), rewire, check, close and secure immersion

heater housing cover(s).

7.5 EXPANSION VESSEL CHARGE PRESSURE

Remove the dust cap on top of the vessel. Check the
charge pressure using a tyre pressure gauge. The pres­sure (with system de-pressurised) should be 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.

7.6 RE-COMMISSIONING

Check all electrical and plumbing connections are se­cure. 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 immersion heater(s) or boiler 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 heating source (immersion heater(s) or

boiler) can then be switched on.

7.7 BENCHMARKTM LOG BOOK

On completion of any maintenance or service of the
Premier Plus the BenchmarkTM “Installation, Com­missioning and Service Record Log Book” should be
lled in to record the actions taken and the date the
work was undertaken.

7.3 STRAINER

Turn off the cold water supply, boiler and immer­sion heaters. The lowest hot water tap should then
be opened to de-pressurise the system. Remove the
Pressure Reducing Valve housing by unscrewing the
four securing screws with the Allen key supplied.
Pull the Reducing Valve cartridge from the Check
Valve 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 sealant. Ensure the four

securing screws are tightened equally.

7.4 DESCALING IMMERSION HEATER(S)

Before removing the immersion heater(s) the unit

must be drained. Ensure the water and electrical
supply and boiler are OFF before draining. Attach

a hosepipe 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.

Direct models:

Open the cover(s) to the immersion heater housing(s)

and disconnect wiring from the thermostat mounted on
top of the immersion heater(s). Remove the thermostat
by carefully pulling outwards from the immersion
heater. Unscrew immersion heater backnut(s) and re­move immersion heater from the unit. A key spanner is
supplied with the Premier Plus unit for easy removal/
tightening of the immersion heater(s). Over time the
immersion heater gasket may become stuck to the
mating surface. To break the seal insert a round bladed

7.0 MAINTENANCE

7.1 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 manu­ally 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 boiler maintenance.

7.2 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.

screwdriver into one of the pockets on the immersion

heater and gently lever up and down.

Indirect models:

Open the cover(s) to the immersion heater housing(s)

and disconnect wiring from immersion heater(s). Re­move thermostat capillary sensors from the pockets

on the immersion heater. Unscrew immersion heater

backnut(s) and remove immersion heater from the
unit. A key spanner is supplied with the Premier Plus
unit for easy removal/tightening of the immersion
heater(s). Over time the immersion heater gasket
may become stuck to the mating surface. To break
the seal insert a round bladed screwdriver into one of
the pockets on the immersion heater and gently lever

up and down.

13

8.0 FAULT FINDING AND

SERVICING

8.1 IMPORTANT

• Servicing should only be carried by authorised

Santon Service Engineers or Agents or by competent
installers in the installation and maintenance of un-

vented water heating systems.

• Any spare parts used MUST be authorised Santon

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 Premier unit may be very

hot, especially following a thermal control failure.
Caution must be taken when drawing water from the

unit.

8.2 SPARE PARTS

A full range of spare parts are available for the Premier
Plus range. Refer to the Technical Data label on the
unit to identify the model installed and ensure the

correct part is ordered.

Description Part no.

Immersion heater (lower) 95 606 946
Immersion heater (upper) 95 606 947
Immersion heater gasket 95 611 822
Immersion heater backnut 95 607 869
Immersion heater key 95 607 861
Tundish 95 605 838
Expansion valve cartridge - 6bar 95 605 864
Expansion valve complete - 6bar 95 607 030
Cold water combination valve complete 95 605 022
Cold water combination valve body 95 605 030
Check valve housing 95 605 028
Pressure reducing valve cartridge 3.5bar 95 607 029
Pressure reducing valve housing 95 605 027
Temperature/Pressure Relief Valve 95 605 810
Expansion vessel 12 litre (100, 120
and 150 litre models) 95 607 863
Expansion vessel 18 litre (170 and
210 litre models) 95 607 864

Cold Water Combination Valve - Exploded view

Expansion vessel 25 litre (250 and
300 litre models) 95 607 612

Direct units only

Combined thermostat and thermal

cut-out 95 612 599
Terminal cover 95 607 836

Indirect units only

Indirect thermostat 95 612 697
Indirect Thermal cut-out 95 612 698
Motorised valve 2 port 95 605 819
Terminal housing 95 607 837
4 Way terminal block 95 607 902

Cable
Gland

Combined

Thermostat &

Thermal Cut-out

- Direct models

Spare Part No:

95 612 599

Expansion Valve
Cartridge
Spare Part No.
95 605 864

Expansion Valve
Complete (6 bar)
Spare Part No.
95 607 030

Valve Body
Spare Part No.
95 605 030

Check Valve
Housing
Spare Part No.
95 605 028

Pressure Reducing
Valve Housing
Spare Part No.
95 605 027

Pressure Reducing
Valve Cartridge
(3.5 bar)
Spare Part No.
95 607 029

Strainer Mesh

Housing Securing
Screws (4 off)

Cold Water Combination Valve Complete
Spare Part No. 95 605 022

Indirect thermostat
Spare Part No:
95 612 697

Indirect Thermal Cut-out
Spare Part No:
95 612 698

4 Way Terminal Block
Spare Part No:
95 612 697

14

8.3 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 Premier Plus unvented water
heater and its associated controls MUST be carried out by
a competent installer for unvented water heating systems.
In case of doubt contact the Santon Service Department
(see contact details at foot of page 16).

DO NOT TAMPER WITH ANY OF THE
SAFETY VALVES OR CONTROLS SUPPLIED
WITH THE PREMIER PLUS AS THIS WILL
INVALIDATE ANY GUARANTEE

TABLE 5 Fault Finding Chart

WARNING

F AU L T P O SSIB LE C A U S E R E M E D Y

N o ho t w a ter fl o w 1 . M ain s s u pp ly o ff 1. C hec k and ope n s top c oc k

2. S traine r bloc k ed 2. Turn off w ater s upply .
R e m ove s t ra in e r and c lean (s e e
S ec tio n 7 . 3 )

3. C old W ate r C o m bina t ion

V alve i n c orre c tly fitte d

3. C hec k and re fit a s req u i red

W ate r fro m hot taps is
c ol d

1. D IR E CT imme rs ion

he a t e r n o t s witc hed o n

1. C hec k and s wi t c h o n

2. D IR E CT imme rs ion

he a t e r t h erm al c ut-ou t has
op e rated

2. C hec k .

R e s et by pus hing

but t o n.

3. IN D IR E CT pro g r a mme r

s et to C entra l H eatin g o n l y

3. C hec k . S et t o a D o m es tic
H o t W ater p ro g ra mme

4. IN D IR E CT boil e r n o t

w o rk in g

4. C hec k boile r o p e ra t i o n. If fault
is s us pe c ted c on s ult b o iler
m a n u fa c t ure r's in s t ru c tions

5. IN D IR E CT therm al c u t-

ou t has o pera t e d

5. C hec k . R e s et by p u s h ing
button on c ut -out . C he ck
op e rat io n o f in dire c t t herm os ta t

6. IN D IR E CT m oto ris ed

val ve n o t c onnec ted
c or rec tly

6. C hec k wirin g and / o r p l u m bing
c on nec tions to m ot o ris ed valve
(s e e F ig. 7 )

W ate r d is c h arg e s 1. IN TE RM ITTE N TLY
fro m E x p ans io n V alve E x pa n s i o n V es s e l c ha rge

pre s s ure has redu c ed b elo w

3.5 b a r

1. S ee S ec t io n 7.5 fo r re ­c ha rg in g pro c edure

2. C O N TIN U A LL Y

a. C old W ate r C o m bina t ion
V alve P re s s ure Re duc er not
w o rk ing c orre c tly

a. C hec k pre s su re from C ol d
W ater C om bin a t ion V alve. If
gre ater than 3 .5b a r re pla c e
P re ssu re R educ e

r c art ridge
b. E xp ans ion V alve s ea t
da m aged .

b. R em ove E xpans io n V alve
c ar t rid ge. C h e ck c ondi t i on o f
s ea t. If n ec e s s ary fit new

E x p ans io n V alve c a rt ridge .
W ate r d is c h arg e s fro m
T& P R elie f V al ve

1. Therm al c ontrol fa ilu re
N O TE w at e r w i ll b e ve ry ho t

1. S wi t c h o ff p o w er t o

imme rs io n he a t e r(s ) a nd s hut

do w n boile r. D O N O T t u rn o ff

w a t e r s upply . W hen d isch a rg e

s to ps c hec k all t he rm al

c on tro l s , rep lac e if faulty .
"M ilky" water O x y ge

nated w at e r W ate r fro m a p ressu ris ed

s y s te m re le a s es o x ygen

bu b b l e s w hen flo wing . The

m ilk in e ss w ill d i s appe a r a ft e r a

s ho rt w hile .

15

9.0 USER INSTRUCTIONS

9.1 WARNINGS
IF WATER ISSUES FROM THE TEMPERA­TURE/PRESSURE RELIEF VALVE ON THE
SANTON PREMIER PLUS SWITCH OFF
ELECTRICAL SUPPLY TO THE IMMER­SION HEATER(S) (DIRECT UNITS) OR SHUT
DOWN THE BOILER (INDIRECT UNITS).
DO NOT TURN OFF ANY WATER SUPPLY.
CONTACT A COMPETENT INSTALLER FOR
UNVENTED WATER HEATERS TO CHECK
THE SYSTEM.

DO NOT TAMPER WITH ANY OF THE SAFETY
VALVES FITTED TO THE SANTON PREMIER
SYSTEM. IF A FAULT IS SUSPECTED CON­TACT A COMPETENT INSTALLER.

9.2 TEMPERATURE CONTROLS – DIRECT

UNIT IMMERSION HEATER(S)

A combined adjustable thermostat and thermal cut-out
is provided for each immersion heater. The thermostat
is factory set to give a water storage temperature of

approx. 55o to 60oC. Access to the thermostat can be

made by opening the immersion heater cover - DIS­CONNECT THE ELECTRICAL SUPPLY BEFORE
OPENING THE COVER(S). Temperature adjustment
is made by inserting a at bladed screwdriver in the
slot on the adjustment disc on top of the thermostat
and rotating. The adjustment range 1 to 5 represents
a temperature range of 10o to 70oC (60oC will be
approximately position 4). If in any doubt contact a

competent electrician.

DO NOT bypass the thermal cut-out(s) in any
circumstances.

9.3 TEMPERATURE CONTROLS – INDIRECT

UNITS (Fig. 9)

The Santon Premier Plus Indirect units are tted with
an Indirect Thermostat and Thermal Cut-out. These

controls must be wired in series with the 2 port mo-

torised zone valve supplied to interupt the ow of

primary water around the heat exchanger coil when the

control temperature has been reached. The controls are

located within the lower grey terminal housing along

with the immersion heater thermostat. The thermostat
is factory set to give a water storage temperature of

approx. 55o to 60oC. Access to the thermostat can be

made by opening the terminal housing cover - DIS­CONNECT THE ELECTRICAL SUPPLY BEFORE
OPENING THE COVER. Temperature adjustment
is made by inserting a at bladed screwdriver in the
adjustment knob and rotating. The minimum ther­mostat setting is 10oC. The adjustment range 1 to 5
represents a temperature range of 30o to 70oC (60oC
will be approximately position 4). If in any doubt

contact a competent electrician.

On indirect units an immersion heater is also provided

for use should the indirect heat source be shut down
for any purpose. The immersion heater control tem­perature is set using the immersion heater (Direct)
thermostat, see section 9.2 above for details..

DO NOT bypass the thermal cut-out(s) in any
circumstances.

9.4 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.

9.5 OPERATIONAL FAULTS

Operational faults and their possible causes are de­tailed in Section 8.0. 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.

16

Specier

Tel: [phone]
Fax: [phone]
E-mail: speci[e-mail]

SANTON

Hurricane Way, Norwich, Norfolk, NR6 6EA

Tel: [phone]

Sales

Tel: [phone]
Fax: [phone]
E-mail: [e-mail]

Service

Tel: [phone]
Fax: [phone]

E-mail:

[e-mail]

10.0 GUARANTEE

This product is guaranteed against faulty materials
and manufacture for a period of 25 years from date
of purchase (with the exception of the Expansion

Vessel which is guaranteed for a period of 5 years

and valves, ttings and electrical parts which are

guaranteed for a period of 2 years) 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 Santon recom­mended type and specication.

• It has only been used for the storage of potable

water.

• 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.

• Within 60 days of installation, the user completes
and returns any Certicate of Registration that may

be supplied with the unit in order to register the prod­uct.

The unit is not guaranteed against damage by frost, and

the inner container with integral immersion heater(s)
is not guaranteed against excessive scale build-up.

Periodic loss of charge pressure from the Expan­sion 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 7.5 for details on how to restore the Expansion
Vessel charge pressure.

This guarantee does not affect your statutory rights.

ENVIRONMENTAL INFORMATION

Santon products are manufactured from many recyclable
materials. At the end of their useful life they should be
disposed of at a Local Authority 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

The policy of Santon is one of continuous product development and, as such, we reserve the right to change
specications without notice.

For the fast and efcient supply of spares
please contact the stockists listed below.

Electric Water Heating Co.

2 Horsecroft Place, Pinnacles, Harlow,
Essex, CM19 5BT
Tel: [phone]
E-mail: [e-mail]

SPD Special Product Division

Units 9 & 10, Hexagon Buisness Centre, Spring­eld Road, Hayes, Middlesex, UB4 0TY
Tel: [phone]

Parts Center

Unit 6 Revolution Park, Buckshaw Village, Chorley,
Lancashire, PR7 7DW
Tel: [phone]
www.partscenter.co.uk

Newey & Eyre

Specialist Products Division

Please contact your local branch

UK Spares Ltd.

Tower Lane, Warmley, Bristol, BS30 8XT
Tel: [phone]

William Wilson Ltd.

Unit 3A, 780 South Street, Whiteinch,
Glasgow, G14 0SY
Tel: [phone]

11.0 SPARES STOCKISTS