Worcester Highflow 400 Electronic Series User manual

HIGHFLOW 400 ELECTRONIC
SERIES
USER INSTRUCTIONS &
CUSTOMER CARE GUIDE
G.C. NUMBERS
APPLIANCE NATURAL GAS L.P.G.
Fanned Flue (RSF) 47 311 61 47 311 64
Balanced Flue (BF) 47 311 62
Open Flue (OF) 47 311 63

EXCELLENCE COMES
AS STANDARD
Thank you for purchasing a Highflow 400 Electronic
gas-fired combination appliance.
Highflow 400 Electronic Series appliances are made by
Worcester Heat Systems and the strictest quality control stan-
dards are demanded throughout every stage of production.
Indeed, Worcester Heat Systems have led the field in inno-
vative appliance design and performance for more than 30
years.
The result is that
your new Highflow 400
Electronic appliance offers
you the very best of every-
thing - quality, efficiency,
economical running costs,
proven reliability and
value for money.
What’s more,
you also have the assur-
ance of our no-nonsense 1
year parts and labour guar-
antee.
And it’s backed up by
Worcester Care Call - a complete maintenance scheme to keep
your boiler operating at peak condition and efficiency.
No wonder that more and more people are agreeing that
when it is gas, it has to be Worcester Highflow 400 Electronic
Series.
Page No.
Operating Instructions
.................................... 3-11
Fault and Breakdowns 12
Maintenance and
Extended Warranty
Information ............ 13-14
Guarantee Details .. 15-16
CONTENTS
2

GAS SAFETY (INSTALLATION AND USE)
REGULATIONS 1998
It is the law that all gas appliances must be installed by a compe-
tent person in accordance with the above regulations. Failure to
install appliances correctly could lead to prosecution. It is in your
interest and that of safety to ensure compliance with the law. The
manufacturers notes must not be taken, in any way, as over-riding
statutory obligations.
WARNING: This appliance must be earthed and protected by a
3 amp fuse.
ELECTRICITY SUPPLY: 230V ~ 50Hz
IMPORTANT: To get the best from your Highflow please read
these instructions carefully.
NOTE: In the event of a fault the appliance should not be used
until the fault has been corrected by a competent person.
GENERAL DESCRIPTION
(See Fig.1.)
The HIGHFLOW 400 ELECTRONIC MODELS are combined
domestic hot water and central heating appliances. They consist of a
gas fired boiler having a varying output of between 8.8/11 kW and 24
kW, a heatbank containing stored primary water, a heat-exchanger to
provide domestic hot water via the boiler, a circulating pump, water
diverting valve and all necessary controls to provide central heating
and mains fed domestic hot water and central heating.
The hot water delivery rate is limited to 18 l/m. The specific
rate, declared as part of the relevant standard, is 20 l/m. To achieve
this a tank temperature of 75°C is required.
The appliances can operate in one of three modes. Hot water
only or hot water and central heating or heating only.
Hot Water Mode:
When a demand is made for hot water by opening a tap or show-
er hot water will be delivered almost immediately. The flow turbine
will energise the pump and circulate primary hot water around the
boiler and water to water heat exchanger. The burner will light to
maintain the temperature of the heatbank.
When hot water is no longer required the appliance will contin-
ue to operate, the burner will cycle a number of times, until the heat-
bank has returned to temperature. The pump will continue to run for
a few minutes to dissipate the residual heat around the appliance.
If no hot water demand is made then the boiler will only use
enough energy to maintain the temperature of the heatbank.
The maximum temperature of the water drawn off from the
heatbank is governed by the setting of the Hot Water Temperature
Control. (See Fig.2.)
A flow restrictor is fitted within the appliance which limits a hot
water delivery rate to a maximum of 18 (±15%) litres/minute.
The restrictor is removed by the installer if a cistern feed hot
water system is installed.
GENERAL
INFORMATION
3

Hot Water and Central Heating Mode:
The appliance will supply heat to the central heating system as
required. A demand for hot water at a tap or shower will override the
central heating function for the period of the domestic hot water
demand.
When domestic hot water is no longer required the burner and
pump will continue to operate until the heatbank is back to the
required temperature.
The appliance will then return to the central heating state and
its normal mode of operation.
Similarly the hot water is occasionally diverted from the central
heating system into the heatbank to maintain the stored primary hot
water temperature.
NOTE: If in doubt about the use of the controls ask your
installer to assist you.
Central Heating Mode:
When a demand is made for heating by the system controls (i.e.
a programmer or room thermostat).
The water diverter valve will open, the pump will energise circu-
lating primary water around the heating system and the burner will
light. The appliance will operate as necessary to maintain the temper-
ature of the radiators at the level set by the adjustment of the Heating
Temperature Control. (See Fig. 2.)
If the system no longer requires heat to maintain the desired
room temperature, the burner will extinguish. The pump will contin-
ue to run for a short period to
dissipate the residual heat from
the appliance and then switch
off.
4
Fig. 1. System Diagram of Highflow 400 Electronic Series.
Primary
Water
circulation
Water
diverter
valve
From
radiators
Mains
cold in
Flow tur-
bine
Domestic hot
water out
Expansion
vessel
Slot in
front cover.
(O.F. only)
Pilot obser-
vation win-
dow.
To
radiators
Circulating
pump
Heat
exchanger
Heatbank
Burner
Boiler

5
CENTRAL HEATING SYSTEM
During the first few hours of operation of the central heating
system, check that all radiators are being heated at an even rate.
Should the upper area of a radiator be at a lower temperature than
the base of the radiator, it should be vented by releasing air through
the venting screw at the top of each radiator. Make sure your installer
shows you how to carry out the operation. Repeated venting will
reduce the quantity of water in the system and this must be replen-
ished for safe and satisfactory operation of the appliance. Should
water leaks be found in the system or excessive venting be required
from any radiator, a service engineer should be contacted and the sys-
tem corrected.
SEALED HEATING SYSTEM
The appliance can be fitted to a sealed heating system which is
pre-pressurised. In this case your installer will advise you on the min-
imum and maximum pressure that should be indicated on the pres-
sure gauge. See Fig. 3. Check regularly that this pressure is main-
tained and contact your installer or maintenance engineer if there is a
permanent significant drop in pressure indicated on the gauge. If the
system loses pressure it should be re-pressurised as instructed by the
installer.
NOTE: Some sealed systems do not require pre-pressurisation. If
this type of system has been used by your installer he will advise you
of any special maintenance that is required to ensure that the system
is always full of water.
Should any water leaks be found in the system or excessive
venting be required from any radiator, a service engineer should be
contacted and the system corrected.
OPEN VENTED HEATING SYSTEM
The appliance may be fitted to an open vented heating system
your installer will advise you. There is no need to check the pressure
gauge.
CLEARANCES
Your installer will have provided adequate space around the
appliance for safety and servicing. Do not restrict this space by the
addition of cupboards, shelves etc. close to the appliance.
Minimum clearances in millimetres.
GENERAL NOTES
BF Models OF Models RSF Models
Left-hand side 5 5 5
Right-hand side 5 70 5
In Front 600 600 600
Above 10 10 10

6
ROOM THERMOSTAT
A room thermostat may be fitted for control of the central heat-
ing temperature. The method of setting a room thermostat varies with
the type and manufacture. Refer to the instructions supplied with the
room thermostat.
THERMOSTATIC RADIATOR VALVES
If thermostatic radiator valves are to be fitted to the system then
they must conform to the requirements of BS2767:1972. It is advisable
to leave one valve permanently set at maximum to prevent the boiler
short cycling.
SHOWERS, BIDETS, TAPS AND MIXING
VALVES
Standard hot and cold taps and mixing valves used with the appli-
ance must be suitable for operating at the available mains pressure. The
use of thermostatically controlled or pressure equalising shower valves
will guard against the flow of water at too high a temperature.
Hot and cold mains fed water can be supplied direct to an over-
rim flushing bidet subject to local water company requirements.
With all mains fed systems the flow of water from the individ-
ual taps will vary with the number of outlets operated simultaneous-
ly and the cold water mains supply pressure to the property. Flow bal-
ancing using ‘Ball-o-Fix’ type valves is recommended to avoid an
excessive reduction in flow to individual outlets.
For further information contact Worcester Heat Systems Ltd.
HOT AND COLD FLOW
If the flow of water demanded from both hot and cold service
outlets is dependent upon mains supply, it may not be possible in
some installations to operate all outlets simultaneously.
WATER MAINS FAILURE
It is important to note that in the event of a mains water supply
failure, no tap water will be available until the mains supply is
restored. Cistern fed hot water supply will stop once the cistern has
emptied but the appliance can still be used for heating provided that
the system is of the sealed system type. Open vent central heating
systems should be turned off until the supply is restored.
USE IN HARD WATER AREAS
In areas of exceptionally hard water supply it is recommended
that an In-Line scale inhibitor be fitted.
Installation should be strictly in accordance with the require-
ments of the local Water Company. An isolating valve to facilitate
servicing should be incorporated.
The water hardness may be determined using the standard test
paper or by reference to the local Water Company.
Further information may be obtained from Worcester Heat
Systems Limited.
AIR SUPPLY FOR OPEN FLUED (O.F.)
APPLIANCES
Fresh air is required for combustion
Your installer will have made arrangements for an adequate sup-
ply of fresh air to the appliance. Do not block up any air ways which
may be let into a wall or door. Do not hang clothes or other com-
bustible materials over the appliance or against the flue pipe.

7
NOTE: Do not place anything on top of the appliance. If the
appliance is fitted in a compartment do not use the compartment for
storage purposes unless it conforms to the requirements of
BS 6798:1987: Section 6. In particular, the flue pipe should not pass
through an airing cupboard space unless protected by a guard (such as
wire mesh) concentrically spaced 25mm, as described in BS
6798:1987.
VENTILATION OF BALANCED FLUED (BF)
AND ROOM SEALED FANNED FLUE (RSF)
APPLIANCES
These are room sealed appliances that do not require air for
combustion from the room. However any ventilation openings in a
wall or door must not be obstructed. Do not allow the flue terminal
fitted on the outside wall to become obstructed or damaged.
NOTE: Do not place anything on top of the appliance. If the
appliance is fitted in a compartment do not use the compartment for
storage purposes unless it conforms to the requirements of
BS 6798:1987: Section 6. It is essential that the airing space is separat-
ed from the boiler space by a perforated non-combustible partition as
described in BS 6798:1987.
CIRCULATING PUMP
This may be fitted with a speed adjuster. If so it will be factory
set at maximum and should not be re-adjusted.
FROST PRECAUTIONS
If the appliance is not to be used for a long period of time and
there is a likelihood of freezing, then the appliance should be
drained. Your British Gas Engineer, or any service engineer will advise
you on suitable frost precautions. For short periods leave the appli-
ance on a low temperature setting.
SERVICE
Annual servicing is important in order to ensure continuing high
efficiency and long life for your appliance. In the event of any diffi-
culty in making suitable servicing arrangements, Worcester Heat
Systems Limited, your British Gas Engineer or other competent per-
sons will discuss regular servicing arrangements and offer a compre-
hensive maintenance contract.
WARNING
If a gas leak exists, or is suspected, turn off the gas supply to the
appliance at the service cock and consult your local British Gas
Engineer or service engineer.
Do not touch any electrical switches to turn them either on or off.
Open all windows and doors. Do not smoke. Extinguish all naked
lights.
CLEANING
Do not use abrasive cleaners on the outer casing. Use a damp
cloth and a little detergent.

8
The appliance is fitted with a blanking panel or an electronic
programmer on the facia panel for the control of domestic hot water
and central heating.
OPERATING MODES
HOT WATER ONLY. The appliance will operate at any time
there is a demand for hot water. Heating temperature control at OFF
(fully anti-clockwise).
OFF. Both hot water and central heating will remain off when
the heating and hot water temperature controls are at OFF (fully anti-
clockwise).
HEATING AND HOT WATER. Hot water will be supplied when a
demand is made. Heating and hot water temperature control at OFF
(fully anti-clockwise).
Central heating will operate continuously in response to a
demand from a room thermostat or thermostatic radiator valves if fit-
ted.
HEATING ONLY. Hot water temperature control at OFF (fully
anti-clockwise). The appliance will operate in response to a demand
from a room thermostat or thermostatic radiator valve, if fitted.
ELECTRONIC PROGRAMMER
Your Installer may have mounted the optional electronic pro-
grammer on the appliance facia panel. Operating instructions are sup-
plied with the programmer.
TEMPERATURE CONTROLS
The Heating Temperature Control gives control over the temper-
ature of water supplied to the radiators when the boiler is serving the
central heating system. This control does not influence the tempera-
ture of the Hot Water which is set by the Hot Water Temperature
Control. The controls have a range as indicated in Fig. 2.
The operating temperatures may be set anywhere within the
range. With a high central heating temperature setting the radiators
will get hotter and high room temperatures will be achievable.
Similarly the temperature of the hot water can be controlled. With
lower settings the radiators and hot water will be cooler but in winter
conditions the central heating and hot water may not reach their
design temperatures.
The temperature controls will shut down the relevant operating
mode when turned fully anti-clockwise.
The Heating Temperature Control is also used to reset any safety
lock-outs by turning it OFF and ON.
WARNING: Do not attempt to adjust any sealed components on
the appliance.
Any interference with sealed components may cause a danger-
ous condition.
OPERATION OF CON-
TROLS

9
Fig. 2. Facia panel.
Heating Temperature Control
Minimum setting
Maximum setting
Optional Facia Mounted Programmer
Power Light
CH ON Light
OFF
HW ON Light
Hot Water Temperature Control

10
TO LIGHT THE APPLIANCE
See Figs 2 and 3.
Set the temperature controls A,B (or programmer Cif fitted) to
OFF. Switch off the electricity supply. Remove the cabinet front panel
by lifting off its mountings. Turn the gas service cock Don. Check
that the red needle on the pressure gauge is not below the required
pressure (sealed systems only) usually 1-1.5 bar.
Switch on the mains electricity indicated by the Power light E.
Turn the heating temperature control Bto max. Set each channel
of the programmer C(if fitted) to ON and the burner will light (not
visible).
Set the programmer (if fitted) to the required position.
Set the temperature controls to the desired settings.
Set the room thermostat, if fitted, to the desired temperature.
Set the central heating temperature control Bto the required position.
TO STOP THE APPLI-
ANCE
For Short Periods; Set the temper-
ature controls (or programmer) to OFF
as indicated by the Demand lights F,G
going out.
For Long Periods; Set the temper-
ature controls (or programmer) to OFF
as indicated by the Demand light
going out. Switch off the mains elec-
tricity indicated by the Power light E
going out.
The facia mounted programmer
will retain its settings for about 4
weeks after which it will return to the
factory set programme. The display
will disappear after approx. 12 hours.
ELECTRICITY SUPPLY
FAILURE
The appliance will not operate
without an electricity supply. Normal
operation of the appliance will resume
after the electricity supply is restored.
TO LIGHT AND STOP THE
APPLIANCE
Fig. 3. Appliance with cabinet front cover removed
Circulating
pump
Expansion
vessel
A
Heatbank
Water
diverter
valve
Pressure
gauge
Gas serv-
ice cock D
B
CEF G