Santon Aquaheat SS V 100 Guide

Installation and User Instructions
Aquaheat Unvented Water Heaters
Models: SS V 50/80 & 100
Please read and understand these instructions before starting work.
Please leave this leaet with the user following installation.
PACK CONTENTS
Heater, Installation & User Instructions.
WARNING
This water heater must only be installed by qualied persons.

2
CONTENTS
SECTION PAGE
1.0 INTRODUCTION 3
2.0 TECHNICAL SPECIFICATION 4
3.0 INSTALLATION 7
4.0 COMMISSIONING 14
5.0 EXPLANATION TO CUSTOMER 15
6.0 MAINTENANCE 15
7.0 SPARE PARTS 18
8.0 FAULT FINDING 20
9.0 ACCESSORIES 21
10.0 GUARANTEE 22
11.0 ENVIRONMENTAL INFORMATION 23
12.0 SPARES STOCKISTS 24

3
1.0 INTRODUCTION
Thank you for purchasing a Santon Aquaheat SS unvented water heater. The Aquaheat
SS water heater is manufactured in the UK to the highest standards and has been
designed to meet all the latest relevant safety specications.
1.1 IMPORTANT POINTS
The Aquaheat SS must be installed and commissioned by a competent person. Please
read and understand these instructions before installing the Aquaheat SS. Following
installation and commissioning, the operation of the Aquaheat SS should be explained
to the user and these instructions left with them for future reference.
The Aquaheat SS is not intended for use by persons (including children) with reduced
physical, sensory or mental capabilities, or lack of experience and knowledge, unless
they have been given supervision or instruction concerning the use of the appliance
by a person responsible for their safety.
Children should be supervised to ensure they do not play with the Aquaheat SS.
The Aquaheat SS hot water cylinder is of unvented type. Its installation is subject
to Building Regulation G3 (England and Wales), Technical Standard P3 (Scotland)
or Building Regulation P5 (Northern Ireland). Installation must be carried out by a
competent person.
Electrical installation must be carried out in accordance with the current IEE Wiring
Regulations.
Prior to installation the unit should be stored in an upright position in an area free
from excessive damp or humidity.

4
1.2 PACK CONTENTS
Before commencing installation please check that the following components have
been supplied in the Installation Kit:
Aquaheat SS Unit (x1)•
Expansion vessel 3/4” BSP male, precharge pressure 3.5bar (x1)•
Expansion vessel wall mounting bracket (x1)•
Pressure reducing valve 3.5 bar, 22mm x 22mm compression (x1) Single •
check valve 22mm x 22mm compression (x1)
Pressure (expansion) Relief Valve 1/2”BSP x 1/2”BSP female, factory set at 6 •
bar (x1)
Tundish, 22mm x 15mm compression (x1) •
3/4” compression nuts (x2)•
Copper olive, 22mm (x2)•
Element plate tool (x1)•
Mounting brackets (x4)•
User Instructions•
Guarantee Card•
Electrical Rating 3.0kW @ 240v / 2.8kW @ 230v
Capacity 50,80 & 100 litres
Weight (100 Litre) 30Kg (empty), 130Kg (full)
Weight (80 Litre) 24Kg (empty), 104Kg (full)
Weight (50 Litre) 18Kg (empty), 68Kg (full)
Operating pressure 0.35 MPa (3.5 bar)
Rated pressure 0.6 MPa (6.0 bar)
Expansion vessel charge pressure 0.35 MPa (3.5 bar)
Expansion relief valve setting 0.6 MPa (6.0 bar)
Minimum supply pressure 0.08 MPa (0.8 bar)
Maximum supply pressure to PRV 1.6 MPa (16.0 bar)
Temperature / Pressure Relief Valve 90°C / 1.0 MPa (10.0 bar)
2.0 TECHNICAL SPECIFICATION

5
PERFORMANCE
TABLE 01: Aquaheat SS Performance; Heatup, Recovery & Heat Loss
MODEL HEAT UP TIME
(MINS)
RECOVERY
(MINS)
STANDING HEAT-
LOSS kWhr/24hr
50 litre 1.5kW 98 64 0.6
50 litre 3.0kW 49 32 0.6
80 litre 1.5kW 162 112 0.8
80 litre 3.0kW 81 56 0.8
100 litre 1.5kW 208 146 1.0
100 litre 3.0kW 104 73 1.0
Heat up times are based on heating from 20°C through 45°C temperature rise.•
Recovery times are based on heating 70% of capacity through 45°C.•
Standing heat losses are based on an ambient air temperature of 20°C and a •
stored water temperature of 65°C.

6
DIAGRAM 01: AQUAHEAT SS WATER HEATER- DIMENSIONS & IMPORTANT FEATURES
01 TEMPERATURE / PRESSURE RELIEF VALVE
02 THERMOMETER
03 COMBINED THERMOSTAT & CUT-OUT
04 ELEMENT
05 TERMINAL BLOCK
06 CABLE CLAMP
07 HOT OUTLET
08 COLD INLET
09 INDICATOR LIGHT
DIMENSION 80 LITRE
50 LITRE 100 LITRE
A958 700 1146
B1043 785 1231
100
'A'
'B'
300
451
01
02
07 08 09
103
472
03
04
05
06

7
Warning: this appliance must be earthed. It is suitable for A.C. supply only. Electri-
cal installation must be carried out by a competent electrician and be in accordance
with the latest I.E.E. wiring regulations.
Ensure the electrical supply is switched off before making any connections to the
Aquaheat SS.
The Aquaheat SS unvented water heater is factory tted with a Temperature/Pressure
Relief Valve which must not be removed, blocked or restricted in any way.
Expansion MUST be accommodated within the system. The expansion vessel &
check valve provided in the installation kit must be installed and will fulll this
function.
No other valves should be placed between the expansion valve and the Aquaheat
SS cylinder unit. The expansion valve connection must not be used for any other
purpose.
3.1 LOCATION
Using Diagram 01 and the dimensions table as a guide mark the positions of the 1.
xing points. Drill and plug the wall with suitable xings.
Fix the top two xings rst followed by the bottom two xings.2.
The Aquaheat SS must be plumb and vertically wall mounted using the wall 3.
brackets tted to the heater. The water connections must always be at the bot-
tom of the unit.
Enough space should be left below the unit for pipe connections and above the 4.
unit for access to the Temperature/Pressure Relief Valve (400 mm minimum).
Refer to Diagram 01 and the dimensions table to determine a suitable position
for the heater.
Ensure that the wall can support the full weight of the unit and that there are no 5.
hidden services (electricity, gas or water) below the surface of the wall.
DO NOT install where the unit may freeze.6.
DO NOT install in direct sunlight or where the unit is open to the elements.7.
The latest IEE wiring regulations may contain restrictions concerning the instal-8.
lation of these units in bathrooms.
NOTE: THE AQUAHEAT WATER HEATER IS HEAVY. PRIOR TO FIXTURE
ENSURE THE WALL IS STRONG ENOUGH TO TAKE THE WEIGHT OF THE
WATER HEATER WHEN FULL.
3.0 INSTALLATION

8
3.2 PLUMBING
To make installation of the Aquaheat SS easier it is supplied with a Non Return 1.
Valve, Expansion Vessel and Pressure Relief Valve.
Plumb the Aquaheat SS water heater as shown below in Diagram 02. Ensure the2.
Pressure Reducing Valve is installed in the correct orientation by reference to the
direction of the ow arrow marked on it.
The water connections to the unit are 3/4” BSP male with Ø22 mm compression 3.
ttings suitable for Ø22 mm copper pipe.
Inlet and outlet are colour coded accordingly for hot and cold. Several hot outlets4.
via conventional taps can be served, however, individual site demands should be
considered when choosing capacity and the number of outlets.
It is recommended that a WRAS listed isolating valve (not supplied) is tted on 5.
the cold water supply to the heater before the Pressure Reducing Valve.
Plumbers Paste must not be used as it can impair the operation of the valves.6.
Aquaheat
50, 80, 100
Litre
Heater
DIAGRAM 02: PLUMBING SCHEMATIC

9
3.3 DISCHARGE
It is a requirement of Building Regulations that any discharge from an unvented
system should be visible and safely conveyed away from the system without danger
to persons in or about the building where it is installed. The discharge pipe should be
tted in accordance with the requirements and guidance notes of Building Regulations.
Building Regulation 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 your local
Building Control Ofcer. The discharge pipework will convey any discharge from the
unvented cylinder Temperature and Pressure Relief Valve. (A discharge pipe will also
be required from the Expansion Valve tted to the Cold Water Combination Valve)
Where practical this can be feed into the discharge pipe from the Aquaheat SS. It is
recommended that an additional tundish is tted into this discharge pipe to give an
early indication of operation of the Expansion Valve.
In some instances it may be possible to discharge into an internal waste system and
soil stack. To do this a self sealing waste valve must be tted into the discharge pipe
after the tundish to prevent foul odours or back-pressurisation from the waste system
entering the building via the tundish. In these systems it is essential that the tundish
is tted in a visible position as the nal point of discharge will not be visible. Consult
the manufacturer’s recommendations with respect to the correct tting, orientation and
waste and soil stack materials selection. It will also be necessary to get dispensation
from your local Building Control Ofcer to discharge in this manner. Discharges from
an unvented system can be up to 95oC for several minutes, ensure any waste or soil
pipe connected to the discharge can safely accept these conditions.
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.”
Water may drip from the discharge pipe of the pressure-relief device and that this
pipe must be left open to the atmosphere.

10
The expansion relief valve is to be operated regularly to remove lime deposits and
to verify that it is not blocked.
The discharge pipe connected to the pressure relief device is to be installed in a
continuously downward direction and in a frost free environment
G3 GUIDANCE SECTION 3.9
The discharge pipe (D1) (see Diagram 03, page 12) 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 600mm of the safety device e.g. the temperature / pressure 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 two pipe sizes larger, and so on. Bends must be taken into account in calculating
the ow resistance. Refer to table 02, page 12 and the worked example.
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 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.
An alternative approach for sizing discharge pipes would be to follow BS6700:1987
Specication for design, installation, testing and maintenance of services supplying
water for domestic use within buildings and their cartilages, appendix E, section E2
and table 21.
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.

11
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 installation
discharging can be traced reasonably easily. The single common discharge pipe
should be at least one pipe size larger than the largest individual discharge pipe
(D2) to be connected. If unvented hot water storage systems are installed where
discharges from safety devices may not be apparent i.e. in dwellings occupied by
blind, 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.
Worked example of discharge pipe sizing:
The example below is for a G1/2 temperature relief valve with a discharge pipe (D2)
having 4 No. elbows and length of 7m from the tundish to the point of discharge.
From Table 02:
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 allowed 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 valve equates to 18m
Subtract the resistance of 4 No. 28mm elbows at 1.0m each = 4.0m•
Therefore the maximum permitted length equates to 14.0m•
As the actual length is 7m, a 28mm (D2) copper pipe will be satisfactory.•

12
TABLE 02: Sizing of copper discharge pipe (D2) for common T&P relief valve
sizes.
Valve
outlet
size
Minimum
size of
discharge
pipe D1
Minimum size
of discharge
pipe D2 from
tundish
Maximum resistance
allowed, expressed as a
length of straight pipe
(i.e. number of elbows
or bends)
Resistance
created by
each bend.
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
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
600mm maximum
Metal discharge pipe (D1) from
Temperature relief valve to tundish
Tundish
Safety device
(e.g. Temperature
relief valve)
DIAGRAM 03: DISCHARGE PIPE ARRANGEMENT

13
3.4 ELECTRICAL
WARNING: THIS APPLIANCE MUST BE EARTHED. IT IS SUITABLE FOR A.C.
SUPPLY ONLY. DISCONNECT THE ELECTRICAL SUPPLY BEFORE REMOV-
ING THE BASE COVER. INSTALLATION MUST BE IN ACCORDANCE WITH
THE CURRENT I.E.E. REGULATIONS.
The electrical supply to the property must be checked to ensure it is of sufcient 1.
current rating and voltage.
The immersion heater supply must include a 16A MCB in the circuit.2.
The circuit must incorporate a double pole isolating switch with a contact separa-3.
tion of at least 3mm in both poles.
The supply cable should be 2.5mm² 3 core HOFR sheathed and must be routed 4.
via the cable seal and entry provided with the outer sheath of the cable rmly
secured by tightening the screws on the cable clamp.
The wires are colour coded as follows:5.
Green and Yellow EARTH
Brown LIVE (L)
Blue NEUTRAL (N)
The Aquaheat SS water heater has one heating element. The heating element is6.
controlled by a combined themostat and thermal cut out, refer to Diagram 04
for wiring details.
DO NOT OPERATE THE IMMERSION HEATER UNTIL THE AQUAHEAT 7.
SS HAS BEEN FILLED WITH WATER.
CUT-OUT SENSOR
THERMOSTAT SENSOR
COMBINED THERMOSTAT
AND CUT OUT
TO ELEMENT
GREEN&YELLOW
BROWN/RED
BLUE/BLACK
ELEMENT EARTH
LIVE (RED)
NEUTRAL (BLACK)
TERMINAL BLOCK
CUT OUT
RESET
A B
12
DIAGRAM 04: WIRING DIAGRAM
NEON POWER INDICATOR

14
4.1 PLUMBING
WARNING: Water that is left standing in a stainless steel water cylinder for long
periods without draw-off will become de-oxygenated and potentially corrode the
vessel material. If the installation is to be left unused following installation and com-
missioning, the water cylinder must be drained or regularly ushed (once a week)
through with fresh mains water.
Check that all installation and discharge pipe requirements have been met.1.
Check that all water connections are tight.2.
Open a hot water tap, turn on mains water supply to the Aquaheat SS.3.
Allow Aquaheat SS to ll and leave hot tap running for a short while to purge 4.
any air and ush out the pipework. Close the hot tap and check the system for
leaks.
Manually test the operation of the Temperature/Pressure Relief Valve and the 5.
Pressure (expansion) Relief Valve. Ensure water ows freely from the valves
and through the discharge pipes.
4.2 ELECTRICAL
PRELIMINARY CHECKS
Ensure all power supplies are switched off.
Check all electrical connections are tight.
Check all earth bonding links are connected, tight and un-damaged.
Check earth continuity, short circuits, polarity and resistance to earth.
Do not switch on the electrical supply until the Aquaheat SS has been lled with 1.
water and checked for leaks.
Check that all electrical requirements have been met.2.
Check that all electrical connections are tight.3.
Switch on the electrical supply. The indicator light will illuminate during heating. 4.
When the set temperature is reached the indicator light will go out.
The set temperature can be adjusted by rotating the control knob. This can be set 5.
to give temperatures in the range 10°C to 70°C. In hard water areas it is advised
that the maximum temperature is restricted to prevent build up of scale.
4.0 COMMISSIONING

15
The Aquaheat SS unvented heater stores water at the temperature set on the 1.
adjustable control knob. This can be set to give temperatures in the range 10°C to
70°C. In hard water areas it is advised that the maximum temperature is restricted
to prevent build up of scale. To avoid risk of freezing when the heater is not in
use for long periods during the winter months, do not switch off the electrical
supply and set the thermostat to its minimum position. N.B. This will not protect
other system pipework.
The indicator lights will be illuminated when the unit is heating.2.
To ensure the heater continues to operate at its optimum performance it should 3.
be periodically maintained in accordance with the instructions given under the
section headed MAINTENANCE.
IMPORTANT NOTES TO USER
DO NOT BLOCK OR RESTRICT THE DISCHARGE FROM ANY SAFETY•
VALVE FITTED.
DO NOT TAMPER WITH ANY SAFETY VALVE FITTED.•
IF WATER DISCHARGES FROM ANY SAFETY VALVE FITTED SWITCH •
OFF THE ELECTRICAL SUPPLY TO THE UNIT IMMEDIATELY. CONTACT
THE SANTON SERVICE TEAM (TEL: [phone]) OR AN APPROVED
INSTALLER. DO NOT TURN THE ELECTRICAL SUPPLY ON AGAIN UNTIL
THE UNIT HAS BEEN CHECKED AND APPROVED BY A QUALIFIED
INSTALLER.
5.0 EXPLANATION TO USER
6.0 MAINTENANCE
WARNING: DISCONNECT FROM ALL ELECTRICAL SUPPLIES BEFORE BE-
GINNING ANY WORK ON THE AQUAHEAT SS. FLUID CONTAINED IN THE
CYLINDER MAY BE VERY HOT!
To ensure the continued safe and efcient operation of the Aquaheat SS it should be
regularly maintained.
Maintenance should be carried out by a competent person and any replacement parts
used should be authorised Santon Aquaheat SS spare parts.
It is recommended that maintenance is carried out annually and should include the
checks detailed in the sections on page 16 & 17.

16
6.1 DESCALING
Little maintenance is required, however in hard water areas the unit will require
periodic descaling to ensure efcient operation. To descale the unit:
Switch off and disconnect the electrical supply. Turn off the water supply to 1.
the unit.
Open a hot tap to relieve any system pressure. Empty unit by opening the drain 2.
cock in the inlet pipework.
Remove the terminal cover by removing the two supporting screws holding it 3.
in place.
Disconnect the electrical terminals to the element. Withdraw the thermostat 4.
and thermal cut-out capillary tubes from the pockets on the element plate.
Remove the element plate assembly by unscrewing the element backnut using 5.
the element tool provided (NOTE: a quantity of water may still be present in
the container, it is recommended that a container be placed under the unit to
collect any spillage).
Remove any loose scale from the container. Carefully clean off any scale from6.
the element and thermostat pocket. DO NOT clean scale from interior container
walls.
Re-assemble the element plate assembly tting a new sealing gasket. Rewire the 7.
unit with reference to Diagram 04 (wiring diagram).
Re-commission the unit following the INSTALLATION and COMMISSIONING8.
instructions.
6.2 SAFETY VALVES
The Temperature/Pressure Relief Valves and the Pressure (Expansion)
Relief Valve should be regularly checked. To check the valve:
Manually operate the valves by twisting the cap. Ensure water ows freely from 1.
the valves and through the discharge pipes (NOTE: the water discharged may be
very hot). Ensure the valves reseat correctly when released.
Clean the strainer incorporated in the Pressure Reducing Valve. To inspect and 2.
clean the strainer turn off the mains water supply to the heater and open a hot tap
to relieve the system pressure. Unscrew the black cap from the Pressure Reducing
Valve and remove. The strainer will be removed with the cap. Wash any particulate
matter from the strainer under COLD CLEAR WATER ONLY. Replace the cap
assembly ensuring the sealing ring is correctly tted. Do not use any other type
of sealant. Close hot tap, open mains stop cock and check for leaks.

17
6.3 EXPANSION VESSEL PRECHARGE PRESSURE
The Expansion Vessel should have a precharge pressure of 3.5 bar (51p.s.i.). This can
reduce over time and eventually require re-charging. To do this:
Turn off water supply to the unit; open a hot tap to relieve system pressure.1.
Remove dust cap from top of Expansion Vessel.2.
Check pre-charge pressure using a tyre pressure gauge. If the pressure is lower 3.
than 3.5 bar (51 p.s.i.) it should be recharged using a tyre pump (Schraeder Valve
type). DO NOT OVER CHARGE.
Re-check pressure and when correct replace dust cap.4.
Turn on mains water supply and close hot tap.5.

18
7.0 SPARE PARTS
The following comprehensive list of spare parts is available for your Aquaheat SS
water heater. Please refer to the Rating Label on the side of your heater before ordering
to ensure the correct spare part is obtained.
Do not replace with parts not recommended by Santon. This will invalidate your
guarantee and may render the installation dangerous.
TABLE 03: Spare parts list
PART DESCRIPTION PART NUMBER
1Thermostat / Thermal Cut Out 95 607 257
2Element Plate Assembly - 3.0kW 95 606 979
3 Indicator Light 95 615 063
4Element Tool (Not Shown) 95 607 861
5 Element Backnut 95 607 869
6 Thermometer 95 607 258
7Electrical Cover & Screws (x2) 95 614 117
8 Thermometer Bezel 95 605 086
9 Blanking Plate 95 605 881
10 Element Gasket 95 611 822
11 Electrical Cover Gasket 95 611 016
12 Pressure Reducing Valve (Not Shown) 95 605 082
13 Expansion Relief Valve 6 Bar (Not Shown) 95 605 083
14 Compression Nuts & Olives (Not Shown) 95 607 253
15 Temperature and Pressure Relief Valve 95 605 084
16 Expansion Vessel 12ltr (Not Shown) 95 607 316
17 Expansion Vessel Bracket (Not Shown) 95 607 317
18 Tundish (Not Shown) 95 605 838

19
15
10
02
05
11
07
01
06
08
09
03
DIAGRAM 05: SPARE PARTS

20
WARNING: DISCONNECT FROM ALL ELECTRICAL SUPPLIES BEFORE BE-
GINNING ANY WORK ON THE AQUAHEAT SS. FLUID CONTAINED IN THE
CYLINDER MAY BE VERY HOT!
The Aquaheat SS should give trouble free operation, however should a problem occur,
the table below should enable most faults to be identied with ease.
Fault Finding should be carried out by a competent person and any replacement parts
used should be authorised Santon Aquaheat SS spare parts.
TABLE 04: Fault nding table
FAULT POSSIBLE CAUSE REMEDY
Water not heating Electrical supply fault.
Thermal cut out tripped.
Check electrical supply. Check cut out. If
operated then reset. Check thermostat &
replace if necessary.
Thermostat setting to low
or faulty.
Check and adjust setting if required. Re-
place if necessary.
Discharge of water from pres-
sure relief valve
(continuously).
Excessive mains water
pressure.
Check pressure from pressure reducing
valve. Replace if greater than 3.5bar (51psi)
Expansion relief valve fault. Replace expansion relief valve.
Discharge of water from pres-
sure relief valve
(intermittently).
Loss of pressure from
expansion vessel.
Check and if necessary recharge expan-
sion vessel precharge pressure.
Discharge of water from
temperature/pressure relief
valve and/or water/steam from
pressure relief valve
Thermostat and thermal cut
out fault.
Replace combined thermostat & thermal
cut out.
No water 󰘱ow Product incorrectly installed. Check inlet & outlet connections are cor-
rect. Check valves are installed in accord-
ance with 󰘱ow direction marks.
Mains water supply not
turned on.
Check mains water supply is turned on.
Blockage in mains water
supply.
Check mains water supply for obstructions.
Check expansion relief valve.
Check strainer in pressure reducing valve.
“Milky water” Oxygenated water Water from a pressurised system releases
oxygen bubbles when 󰘱owing. The milki-
ness will disappear after a short while.
8.0 FAULT FINDING