Protherm Provitherm 28 KTV Manual

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This is a Cat II2H3+ appliance
User, Installation
and Servicing Instructions
Manufactured exclusively for Plumb Center by Hepworth Heating Division
28 kW wall hung combination boiler
xxxx
5. April 2002

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Users’ Instructions
Introduction ...................................................................................................... 2
Controls and lighting ....................................................................................... 2
Draining and filling .......................................................................................... 8
Heating safety valve ........................................................................................ 8
Servicing/maintenance .................................................................................... 8
Cleaning .......................................................................................................... 8
Boiler casing .................................................................................................... 8
Installation Instructions
Introduction ...................................................................................................... 9
Technical data Provitherm 28 KTV ................................................................ 11
Dimensions .................................................................................................... 12
Pressure available ......................................................................................... 12
Boiler schematic ............................................................................................ 13
Installation section ......................................................................................... 14
Terminal positions ......................................................................................... 14
Heating and hot water system design ........................................................... 15
Boiler installation ........................................................................................... 18
Horizontal flue installation ............................................................................. 18
Vertical flue installation .................................................................................. 21
Flue configurations ........................................................................................ 22
Electrical connection .....................................................................................23
Commissioning .............................................................................................. 24
Servicing Instructions
Routine cleaning and inspection .................................................................. 27
Replacement of parts ....................................................................................28
Schematic wiring diagram ............................................................................. 33
Fault finding ................................................................................................... 34
Conversion to LPG ........................................................................................36
Mandatory warning for CE countries
WARNING, these appliances were designed, approved and inspected to meet the
requirements of the English market. The identification plate located on the inside of
the appliance certifies the origin where the product was manufactured and the coun-
try for which it is intended.
If you see any exception to this rule, please contact your nearest stockist.
Thank you in advance for your assistance.
Note: The boiler serial number is marked on the data label attached to the fascia
behind the front panel. Refer to the ‘Introduction’ section for a description of the
basic functions of the boiler. The ‘User’ section describes how to safely operate
the boiler.
Provitherm 28 KTV

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Diagram 1
Controls:
1 – mains on/off switch 6 – reset button
2 – system pressure LED 7 – increase button
3 – central heating LED 8 – decrease button
4 – display 9 – pressure/mode button
5 – domestic hot water LED
The Bar/Mode button functions
1st press of button – the system pressure is displayed in bar
LED (2) lights
2nd press of button – hot water adjusting mode
LED (5) flashes
3rd press of button – heating water adjusting mode
LED (3) flashes
4th press of button – reverts to standby mode
To start the boiler
Switch on the mains switch (display will light up). The version of the software used is
displayed for 2 sec.
To stop the boiler
Switch off the mains switch (display will go out)
If the boiler is to be out of operation for a long period, turn off the gas service cock.
Boiler setting
All parameters are adjustable by means of 3 buttons, pushing the RESET button
restarts the boiler.
Note: Buttons must be pressed in the middle.
Make sure that:
• The boiler is connected to the electrical supply.
• The boiler gas service cock is open.
• The CH system is filled up and pressurized between 1 and 2 bar.
The boiler is now ready to start.
USERS INSTRUCTIONS
The Provitherm 28 KTV is a wall mounted combination boiler providing central heating
and instantaneous domestic hot water.
These instructions should be carefully followed for the safe and economical use of your
boiler.
Gas leak or fault
If a gas leak or fault exists or is suspected, turn the boiler and gas supply off and
consult the local gas company or your Installer/Service provider.
In case of power supply failure
The boiler no longer operates.
As soon as power supply is restored, the boiler will restart automatically.
In case of loss of water in the system
CAUTION: The boiler is installed as part of a sealed system which must only be
drained and filled by a competent person.
If the pressure LED diod (2) flashes the pressure in CH system is less than 0.8 bar
and the system must be filled up immediately.
Important notice: A central heating system cannot operate satisfactorily unless it is
properly filled with water and unless the air initially contained in the piping systems
has been properly bled off. If these conditions are not satisfied, air noise will occur
within the system and the boiler may fail to operate.
Air in the heating system
Persistent air in the heating system may indicate leaks in the system or corrosion
taking place. Call your Installer /Service provider.
Overheating safety
In the event of problem, the overheat safety device causes safety shutdown of the
boiler. If this happens, call your Installer/Service provider.
CONTROLS AND LIGHTING
The control panel is located at the lower front of the boiler casing. The controls on this
panel allow the boiler to be started, shut down, controlled and monitored during use,
see diagram 1.
The following information is displayed:
•Actual heating temperature (°C) - LED (3) lights on
displayed during standby
•Actual domestic hot water temperature (°C) - LED (5) lights
displayed during hot water demand
•System pressure (bar) – LED (2) lights
for 25 sec after Bar/Mode button is pressed
•Diagnostic messages – displayed letter F and numbers from 0 to 4

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P– . . . . . . . . without a shift P5 . . . . . . . . . . . . . . +3°C
P1 . . . . . . . . . . . . . –15°C P6 . . . . . . . . . . . . . . +6°C
P2 . . . . . . . . . . . . . . –9°C P7 . . . . . . . . . . . . . . +9°C
P3 . . . . . . . . . . . . . . –6°C P8 . . . . . . . . . . . . . +15°C
P4 . . . . . . . . . . . . . . –3°C P9 . . . . . . . . . . . . . +21°C
The values with the minus sign are deducted from the HCW temperature (and the
values with the plus sign are added to it) determined by the weather comp. curve in
dependence on the outside temperature.
Example:
- Let the selected curve slope be E6, and the outside temperature be –10°C, for which
the CHW temperature determined by the E6 curve is 73°C.
- If the P3 shift is selected (i.e., by –6°C), the resulting CHW temperature is 73 – 6 =
67°C.
The value is set in the memory by pushing the Bar/MODE button and activating the
following mode.
Diagram of mode setting
Domestic hot water setting
• Press Bar/Mode button until LED (5)
flashes.
• Using buttons (7) and (8) set the desired
hot water temperature
Setting steps: 40, 42, 45, 48, 50, 52,
55, 58, 60 °C
• Set ´– –´ if hot water is not required.
• Press Bar/Mode button to save new set-
ting.
Heating setting / summer mode setting
• Press Bar/Mode button until LED (3)
flashes.
• Using buttons (7) and (8) set the desired
heating temperature
Setting steps: 45, 50, 55, 60, 65, 70,
75, 80, 85 °C
• Set ´– –´ if only hot water is required
(summer mode).
• Press Bar/Mode button to save new set-
ting.
The heating will operate according to the requirements of the timeclock and/or room
thermostat if fitted or, will operate according to the system requirements. Domestic hot
water (DHW) always has priority over central heating (CH).
Note: All new settings are stored by pressing Bar/MODE button. If Bar/MODE button is
not pressed for 20 sec the display reverts to standby mode and old settings are
retained.
Helpfull hint
If you get confused and wish to start again, switch boiler off, press and hold button (8)
and switch boiler on by main switch. The boiler will revert to the internal factory set
programme (heating temperature 80 °C, hot water temperature 50 °C, maximum
heat output).
Weather comp. control - curve slope
Push the Bar/MODE button. Code „E“ + a number between 1 and 9, or a dash, is
displayed. The curve is selected by buttons (8) and (7) – the higher the number in the
code, the higher the curve slope, cf. Diagram 1.
Note: If we want to use the weather comp. control, an external sensor must be connected
and the boiler must not be in the SUMMER operational mode. If no external sensor
is connected, the F5 defect code is displayed!
The value is set in the memory by pushing the Bar/MODE button and activating the
following mode.
Weather comp. mode – curve parallel shift
Push the Bar/MODE button. Code „P“ + a number between 1 and 9, or a dash, is
displayed. The required shift, or „P–“ for no shift, is selected by buttons (8) and (7) as
follows:
Example:
- Let the selected curve slope be E6, and the outside temperature be –10°C, for which
the CHW temperature determined by the E6 curve is 73°C.
- If the P3 shift is selected (i.e., by –6°C), the resulting CHW temperature is 73 – 6 =
67°C.
The value is set in the memory by pushing the Bar/MODE button and activating the
following mode.
Safety lockout
In the event of a safety lockout, the digital display will show ‘F1’.
Reset boiler by pressing the RESET button.
IMPORTANT: If safety lockout occurs frequently, or if any other fault is indicated, contact
your Installer/Service Provider.

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DRAINING AND FILLING
CAUTION: The boiler is installed as part of a sealed system which must only be
drained and filled by a competent person.
If the pressure drops to 0.8 bar the pressure LED on the Bar/MODE button starts to
flash. The boiler will continue to work, but the LED warns that pressure in the CH
system is on the low limit and CH system must be filled. To fill the system, open the tap
on the filling loop below the boiler. Press the Bar/MODE button to read the system
pressure. When the pressure is between 1 and 2 bar, close the tap.
Note: If there is persistent loss of system pressure, you must consult your Installer/
Service Provider.
HEATING SAFETY VALVE
CAUTION: A safety valve with a discharge pipe is fitted to this boiler.
The valve MUST NOT BE TOUCHED except by a competent person. If the valve
discharges at any time, switch the boiler off and isolate it from the electrical supply.
Contact your Installer/Service Provider.
SERVICING/MAINTENANCE
To ensure the continued efficient and safe operation of the boiler, it is recommended
that it is checked and serviced at regular intervals. The frequency of servicing will
depend upon the installation conditions and usage but, in general, once a year
should be enough.
CLEANING
The boiler casing can be cleaned with a damp cloth followed by a dry cloth to polish.
Do not use abrasive or solvent cleaners.
BOILER CASING
CAUTION: Do not remove or adjust the casing in any way, as incorrect fitting may
result in faulty operation.
If in doubt, contact your Installer/Service Provider.
INSTALLATION INSTRUCTIONS
INTRODUCTION
The Provitherm 28 KTV is a wall mounted combination boiler providing central heating
and instantaneous domestic hot water.
The boiler is of the II2H3+ category for use with Natural gas (G20) as distributed in the
United Kingdom, or with Butane or Propane gas (G30/G31) with the appropriate
conversion kit.
Conversion kit:
Conversion . . . . . . . . . . . . . . . . . . . . Provitherm 28 KTV
Natural gas (G20) to G30/G31 . . . . . . . SPB-28KTVJ
Modification must only be carried out by a suitably qualified engineer.
Boilers burning LPG or similar gases MUST NOT be fitted in basements or below
ground level.
These instructions should be carefully followed for the safe and economical use of your
boiler.
The boiler has a fan assisted, balanced, flue which both discharges the product of com-
bustion to, and draws the combustion air from the outside of the building.
Accessories
A range of accessories are available including, vertical flue components. For further
information, contact you nearest Plumb Center branch.
Gas Safety (Installation and Use) Regulations
In the interests and that of gas safety, it is the law that ALL gas appliances are installed
and serviced in by a competent person in accordance with the above regulations.
Gas leak or fault
If a gas leak or fault exists or is suspected, turn the boiler and gas supply off and consult
the local gas company or your Installer/Service Provider.
Boiler controls
The control panel, located at the lower front of the boiler, allows the boiler to be started,
shut down, controlled and monitored during use, refer to ‘Users Instructions’.

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Diagram 2
Diagram 3
1 – Heating flow (pipe diameter 22 mm)
2 – Hot water outlet (pipe diameter 15 mm)
3 – Gas inlet (pipe diameter 22 mm)
4 – Cold water mains inlet (pipe diameter 15 mm)
5 – Heating return (pipe diameter 22 mm)
6 – Wall
7 – Wall fixings
8 – Outer cover
DIMENSIONS AND PRESSURE AVAILABLE
Provitherm
28 KTV
A 800
B 450
C65
D 225
E83
F 228
G 180
H 330
I 105
J 160
K70
PROVITHERM 28 KTV – TECHNICAL DATA
CE Certification ........................................ n° ....................................................... 0063BL3573
Class ................................................................................................................................. II2H3+
Type................................................................................................ ........................... C12, C32
Gas type ........................................................................ G20 ................. G30 ................. G31
Max. / min. heat input ............................. kW ......... 30.3/13.1 .........30.3/13.1 ........ 30.3/13.1
Max. / min. heat output ........................... kW ......... 27.6/11.0 .........27.6/11.0 ........ 27.6/11.0
EFFICIENCY (PCI)
Nominal efficiency .................................... % ..................................................................... 82.3
Efficiency at 30% load ............................. % ..................................................................... 80.5
HEATING
Temperature range ................................. °C ............................................................... 45 – 85
Expansion vessel ....................................... l .......................................................................... 7
Expansion vessel pressure .................. bar .......................................................................... 1
Max. working pressure .......................... bar .......................................................................... 3
Max. system temperature ...................... °C ........................................................................ 85
Max. system capacity ................................ l ...................................................................... 130
HOT WATER
Flow rate at 30°C temperature rise ..... l/min ..................................................................... 13.0
Flow rate at 35°C temperature rise ..... l/min ..................................................................... 11.1
Min. water flow ..................................... l/min ....................................................................... 2.7
Max. / min. supply pressure .................. bar ..................................................................... 6 / 1
Temperature range ................................. °C ............................................................... 40 – 60
ELECTRICAL DATA
Voltage / frequency ............................. V/Hz ............................................................ ~230 / 50
Current ...................................................... A ..................................................................... 0.63
Power ....................................................... W ...................................................................... 145
Level of protection ................................... IP ................................................................ IP X4D
DIMENSIONS
Width / height / depth ............................ mm ............... ......... ......................... 450 / 800 / 330
Weight ..................................................... kg ..................................................................... 40.5
CONNECTIONS
Heating flow / return .............................. mm ........................................................................ 22
Domestic Water inlet / outlet ................. mm ........................................................................ 15
Gas ....................................................... mm ........................................................................ 22
Flue products outlet / air inlet ∅ ............ mm..................................horiz. 60/100, vert. 80/125
Horizontal flue length min. – max. ........... m ................................................................ 0.5 – 3
Vertical flue length min. – max. ................ m ................................................................... 1 – 9
GAS SUPPLY PRESSURE
Burner pressure ................................. mbar ........ 2.5 – 14.0 ........ 4.9 – 27.5 ....... 4.9 – 36.0
Nominal pressure ............................... mbar .................... 20 .................... 29 .................... 37
Injectors diameter ............................. ∅mm ................... 1.2 ................. 0.73 ................. 0.73
GAS CONSUMPTION
Q max / Q min ..................................... m3/h ............... 3.2 / 1.4 ............ 2.2/ 1.0 kg/h ............ 2.2/ 1.1 kg/h
Air flow .................................................. m3/h .................. 135 .................. 135 .................. 135

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INSTALLATION SECTION
Clearances
To allow for servicing, the boiler should be installed with the following clearances:
50 mm either side of the boiler
600 mm to the front of the boiler
300 mm below the boiler
200 mm above the boiler
TERMINAL POSITION
The minimum acceptable spacings from the terminal to obstructions and ventilation
openings are shown in diagram 5 below:
Minimum dimensions (in mm) for the positioning of flue terminals
Diagram 5
a Under a window . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300
b Under an air vent . . . . . . . . . . . . . . . . . . . . . . . . . . . 300
c Under a gutter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
d Under a balcony . . . . . . . . . . . . . . . . . . . . . . . . . . . 300
e From an adjacent window . . . . . . . . . . . . . . . . . . . . 300
f From an adjacent air vent . . . . . . . . . . . . . . . . . . . . 300
g From vertical drain pipes or soil pipes . . . . . . . . . . . . 75
h From an external corner of the building . . . . . . . . . . 300
i From an internal corner of the building . . . . . . . . . . 300
l From the ground or from another floor . . . . . . . . . . . 300
m Between two terminals vertically . . . . . . . . . . . . . . 1500
n Between two terminals horizontally . . . . . . . . . . . . . 300
Diagram 4
BOILER SCHEMATIC
1 – Air pressure switch
2 – Fan
3 – Heat exchanger
4 – Burner
5 – Gas valve
6 – Expansion vessel
7 – Pump
8 – Water flow sensor
9 – Pressure gauge connec-
tion
10 – By-pass pipe
11 – Safety valve
12 – Heating return
13 – Domestic cold water inlet
14 – Gas inlet
15 – DHW thermistor
16 – DHW outlet
17 – Automatic by-pass
18 – Heating flow
19 – Drain
20 – Microswitch
21 – Loss of water pressure switch
22 – 3-way valve
23 – Differential valve
24 – Microswitch
25 – Secondary heat exchanger
26 – CH temperature sensor
27 – High limit thermostat

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Safety valve discharge
WARNING: It must not discharge above an entrance or window or any type of pub-
lic access area.
Connect the safety valve discharge pipe to the valve, the discharge must be ex-
tended using not less than 15 mm o.d. pipe, to discharge in a visible position out-
side the building, facing downward, preferably over a drain. The pipe must have a
continuous fall and be routed to a position so that any discharge of water, possibly
boiling or steam, cannot create any danger to persons, damage to property or ex-
ternal electrical components and wiring. Tighten all pipe connection joints.
Gas connection
The supply from the governed meter must be of adequate size to provide a constant
inlet working pressure of 20 mbar for Natural gas (28 – 30 mbar for Butane or 37 mbar
for Propane).
To avoid low pressure problems, it is recommended that the supply is taken to the
boiler using 22 mm pipe as far as possible.
On completion, the gas installation must be tested using the pressure drop method
and purged in accordance with the current issue of BS6891.
Gas Safety (Installation and Use) Regulations
In your interests and that of gas safety, it is the law that ALL gas appliances are
installed and serviced by a competent person in accordance with the above regula-
tions.
Statutory requirements
The installation of this boiler must be carried out by a competent person in accor-
dance with the relevant requirements of the current issue of:
The Gas Safety (Installation and Use) Regulations
The Building Regulations
The local water company Bylaws
The Building Standards Regulations (Scotland)
The Health and Safety at Work Act
Sheet metal parts
WARNING: When installing or servicing this boiler, care should be taken when handling
the edges of sheet metal parts to avoid the possibility of personal injury.
Installing the boiler
Prior to installing the boiler, the system must be thoroughly flushed to eliminate any
foreign bodies and contaminents such as filings, solder, particles, oil, grease etc.
Note: Solvent products could cause damage to the system.
HEATING SYSTEM DESIGN
The Provitherm 28 KTV is compatible with any type of sealed system installation, i.e.
radiators, fan convectors etc.
Pipe sectional areas shall be determined in accordance with normal practices, using
the pump curve, refer to ‘Technical Data’. The distribution system shall be calculated in
accordance with the output requirements of the actual system, not the maximum output
of the boiler. However, provision shall be made to ensure sufficient flow so that the
temperature difference between the flow and return pipes is less than or equal to 20 °C.
The minimum flow is 500 l/h.
The piping system shall be routed so as to avoid any air pockets and facilitate perma-
nent venting of the installation. Bleed fittings shall be provided at every high point of the
system and on all radiators.
The total volume of water permitted for the heating system depends, amongst other
things, on the static head in the cold condition. The expansion vessel on the boiler is
pressurised at 1 bar (corresponding to a static head of 10 m wg.) and allows a maximum
system volume of 130 litres for an average temperature of 75 °C and a maximum service
pressure of 3 bar. This pressure setting can be modified at commissioning stage if the
static head differs.
Provision shall be made for a drain valve at the lowest point of the system.
Thermostatic radiator valves are permitted, however, not all radiators must be fitted with
this type of valve and particularly where the room thermostat is fitted.
A WRC approved filling loop is supplied with the boiler to enable correct filling of the
system.
In all cases, it is ESSENTIAL that the system be thoroughly flushed prior to installing the
new boiler.
Domestic hot water system design
Copper tubing or plastic Hep2O may be used for the domestic hot water system. Unnec-
essary pressure losses should be avoided. The domestic hot water supply pressure
must be between 1 and 6 bar. If the pressure exceeds 6 bar, a pressure reducing valve
must be fitted. In known hard water areas, it is recommended that
a suitable scale reducing device is fitted to the cold water
supply to the boiler.
Diagram 6
Boiler connections
AHeating flow
BHot water outlet
CGas connection
DCold water mains inlet
EHeating return
FSafety valve discharge connection
Heating system connections
- Pipe diameter 22 mm.
Hot water system connections
- Pipe diameter 15 mm.
Gas connection
- Pipe diameter 22 mm.
Safety valve discharge connection
- Pipe diameter 22 mm.
Note: White colored washers must be used for the
hot water system connections.

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Diagram 8
Standart top
outlet flue
90° elbow
Extension
pipe
Standart top
outlet flue
• Fit flue through hole in wall and pull up so that external collar (G) is flush against
outside wall.
• Fit seal and clamp (C) to flue and assemble into elbow (D) making sure that both
inner and outer pipes are sealed properly.
Note: Maximum horizontal length with no bends is 3 m. For horizontal flue lengths up to
1 m the restrictor must be left in the fan outlet, see diagram 8. For horizontal flue lengths
between 1 and 3 m remove the restrictor (R).
• Tighten up clamp using screws provided.
Note: Should it be necessary to cut the flue, always cut equal amounts from both in-
ner and outer pipes.
Always cut the end furthest from the terminal.
For each 90° flue bend fitted, reduce overall flue length by 1 m.
For each 45° flue bend fitted, reduce overall flue length by 1/2 m.
Horizontal flue kit
Flue extension kit
90° concentric bend kit
45° concentric bend kit
AAir inlet pipe
BTerminal
CSeal and clamp
DElbow
EGasket
FScrews
GExternal rubber sealing collar
IInternal plastic collar
J‘O’ rings
• Fit gasket (E) onto underside of flue
elbow (D) - see diagram 8.
• Carefully insert ‘O’ ring (J) into upper and lower parts of
inner elbow.
• Fit elbow onto spacer ensuring elbow inner connection lo-
cates correctly onto fan outlet.
• Fit external rubber sealing collar (G) onto air inlet pipe (A).
BOILER INSTALLATION
To install the boiler, proceed as follows:
• Allowing sufficient clearances for servicing/repair, place the template on the wall.
Note: The boiler can be installed only on the closed wall.
• Determine the position of the flue hole and drill hole for flue, preferably using a 120 mm
core drill.
• Drill two 10 mm holes for the wallplugs supplied.
• Screw fixing screws supplied into wallplugs, leave proud by approx. 10 mm.
Note: Boiler fixing holes are keyhole type slots at the top of the boiler to allow easy
hanging of boiler.
• It is recommended to fit the safety discharge pipe before hanging the boiler on the
wall.
• Hang the boiler on the screws and tighten screws.
Note: As a option the hanging bracket can be used. Two screws are sufficient for fixing
of the hanging bracket. Hanging bracket fixing screws have to be fully tight before the
boiler is hung on.
Pipework connections
• Remove plastic caps from boiler connections.
• Connect the central heating pipework connections and isolating cocks as shown on
diagram 6.
• Connect the domestic cold water inlet connection and isolating cock.
• Connect the hot water outlet connection.
• Connect the gas connection and isolating cock.
• Finally, connect the filling loop between the cold water inlet pipe and the heating flow
pipe.
HORIZONTAL FLUE INSTALLATION
Diagram 7

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FLUE CONFIGURATIONS
Diagram 10
VERTICAL FLUE INSTALLATION
• Fit gasket (E) onto underside of vertical adaptor (O) – see diagram 9.
• Carefully insert ‘O’ ring (J) into vertical adaptor inner spigot.
• Fit vertical adaptor (O) ensuring adaptor inner connection locates correctly onto
fan outlet.
• Fit extension pipes (M) as required.
• For pitch roof installation, fit pitch roof flashing.
• Fit flue terminal (L) onto roof ensuring flashing makes a watertight joint.
Note: Maximum vertical height with no bends is 9 m.
Should it be necessary to cut the flue, always cut equal amounts from both
inner and outer pipes.
Connect condensate trap (supplied) to vertical flue adaptor when flue length
exceeds 3 m.
Connect 15 mm plastic pipe (not supplied) to a suitable drain.
For vertical flue lengths up to 4 m the restrictor must be left in the fan outlet,
see diagram 8.
For vertical flue lengths between 4 and 9 m, remove the restrictor (R).
For each 90° flue bend fitted, reduce overall flue height by 1 m.
For each 45° flue bend fitted, reduce overall flue height by 1/2 m.
Roof terminal (black)
Pitched roof flashing
Flue extension pipe
90° concentric bend kit
45° concentric bend kit
flue outlet adaptor c/w condensate trap
Diagram 9

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COMMISSIONING
The commissioning and first firing of the boiler must only be carried out by a com-
petent person.
To gain access to the inside of the boiler undo screw securing front panel at the boiler
bottom, remove front panel by pulling forwards, lifting it up and off. Note – upper edge of
front casing is fixed to the boiler by means of 2 pins.
Filling the system
• Check that the gas meter tap is closed.
• Conect boiler to electrical supply.
• Place switch (1) diagram 1 to possition ‘I’ FO is displayed and the pump runs for
about one minute.
• Press the BAR/Mode button, see diagram 1. Value of system pressure (0.0) is dis-
played and LED (2) – see diagram 1 – lights.
Note: The pressure is displayed for about 25 sec. After this time the display comes
back to the standby mode. The pressure can be displayed after pressing Bar/Mode
push button again.
• Open isolating valves (A, Eand D) see diagram 6.
• Undo, but not remove, cap on automatic air vent on the top of the pump.
• Fill system by opening system filling loop until a pressure of between 1 and 2 bar is
shown on the display.
• Bleed each radiator until a continuous jet of water is obtained.
• Do not retighten automatic air vent cap.
• Open various hot water taps to bleed hot water circuit.
• Make sure that pressure is between 1 and 2 bar. Re-pressure as necessary.
Important: When venting air from boiler, do not touch the schrader valve on the expan-
sion vessel, it is NOT a vent.
Starting the boiler
Before starting the boiler check that:
- The gas meter tap is open.
- The boiler gas service cock is open.
- The water isolating cocks are open.
- The boiler is connected to the electrical supply.
First starting up
• Place main switch (1) diagram 1 to position ‘I’
• Set maximum heating water temperature (85°C), as described in ‘Users Instruc-
tions’ and check that any external controls, if fitted, are calling for heat.
• Allow the temperature to rise to the maximum value, with all radiator valves open. Air
contained in the water of central heating system will be automatically released through
the automatic air vent. Air trapped at the hightest point of the system must be released
by bleeding the radiators.
On reaching maximum temperature, the boiler should be turned off and the system
drained as rapidly as possible whilst still hot.
• Refill system to a pressure at least of 1 bar and vent as before.
• Restart boiler and operate until a maximum temperature is reached. Shut down boiler
and vent air from heating system. If necessary, top up heating system and make sure
that a pressure at least of 1 bar is indicated on the display when system is COLD.
Diagram 11
ELECTRICAL CONNECTION
Warning: This boiler must be earthed.
All system components must be of an approved type.
Connection of the whole electrical system and any heating system controls to the elec-
trical supply must be through a common isolator.
Isolation should preferably be by a double pole switched fuse spur box having a mini-
mum contact separation of 3 mm on each pole. The fused spur box should be readily
accessible and preferably adjacent to the boiler. It should be identified as to its use.
A fused three pin plug and shuttered socket outlet may be used instead of the fused spur
box, provided that:
a) They are not used in a room containing a bath or shower.
b) Both the plug and socket comply with the current issue of BS1363.
The mains electrical supply must be maintained at all times in order to provide domestic
hot water and frost protection.
It is recommended that a room thermostat is fitted.
Thermostatic radiator valves may be installed in addition to the room thermostat.
Note: For further information, see The Building Regulations 1991 - Conservation of
fuel and power - 1995 edition - Appendix G, table 4b.
DO NOT INTERRUPTTHE MAINS SUPPLYTOTHE BOILER WITH ATIME SWITCH OR
PROGRAMMER.
The Provitherm 28 KTV is delivered with 1metre mains supply lead ready connected.
The electrical supply cable is the original spare part and must be replaced only by
original supply cable for PROVITHERM 28 KTV boiler.
Warning: If the supply cord is damaged, it must be replaced by the Installer/Service
provider to avoid a hazard.
External controls
The boiler will work for heating AS DELIVERED without a room thermostat fitted pro-
vided the two wires on the integral external controls connection REMAIN LINKED
TOGETHER (as supplied). If a room thermostat is required, it must be connected as
shown below and the link must be removed.
ANY ROOM THERMOSTAT USED MUST BE OF THE VOLTAGE FREE TYPE.
WARNING: ON NO ACCOUNT MUST ANY ELECTRICAL VOLTAGE BE APPLIED TO
EITHER OF THE TERMINALS OF THE EXTERNAL CONTROLS CONNECTION
WARNING: This boiler must be wired in accordance with these instructions. Any fault
arising from incorrect wiring cannot be put right under the terms of the guarantee.

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Diagram 14
Safety devices
Air flow rate safety device
If an obstruction, even partial, of the flue occurs, the built in safety system of the boiler will
turn the boiler OFF. The boiler will be ready to operate when the fault has been cleared.
In case of power supply failure
The boiler no longer operates. As soon as power is restored, the boiler will be automat-
ically restarted. If the boiler does not restart, the overheat device may need resetting.
Overheat safety
In the event of overheating, the overheat safety
device causes safety shutdown of the boiler. The
digital display will show error code F1. To reset,
let the boiler cool down, press the reset button on
the safety device (a), see diagram 20 and reset
boiler controls by means of the reset button (6).
Note: wire connections to overheat thermostat
are mains voltage.
Important notice
A central heating system cannot operate satis-
factorily unless it is properly filled with water and unless the air initially contained in the
pipework system has been properly bled off. If these conditions are not satisfied, air
noise will occur within the system and the boiler may fail to operate.
To reset the boiler (other than for overheating) use the reset button on the fascia, see
diagram 14.
The Provitherm 28 KTV boiler has a built-in frost protection device that protects the
boiler during freezing conditions. This device works irrespective of any room thermostat
setting and only protects the boiler.
Should the temperature within the central heating circuit of the boiler fall below 10 °C,
the pump will switch on providing the electrical supply has been left connected. If the
temperature falls below 8 °C, then the burner will operate until the water temperature
increases to 25 °C. Should the electrical supply have been disconnected and the boiler/
system has frozen, the boiler will not start up until the boiler/system has been cleared.
Gas installation
It is recommended that any air is purged from the supply at the gas inlet test point on the
gas valve, see diagram 12.
1- Inlet test point
2- Outlet test point
Gas pressures
• Shut down boiler.
• Undo screw on gas inlet test point ‘1’ on gas valve, see
diagram 12.
• Connect a suitable pressure gauge.
• Start boiler as described in ‘Users Instructions’.
• Check that there is a constant pressure of 20 mbar for
Natural gas (28 – 30 mbar for Butane or 37 mbar for
Propane). If the pressure is insufficient, it is necessary
to check the gas supply/pipework and correct any fault.
• Shut down boiler.
• Remove pressure gauge, tighten up carefully test point
screw and check for gas soundness.
Setting the central heating output
The central heating output must be set in accor-
dance with the system requirements.
Setting procedure as follows:
•Push and hold the Bar/Mode button for at
least 8 sec. The display will switch to service
mode, the symbol n- will be displayed
•Set the desired output value from n1 to n9
by means of buttons (7) and (8) according
to the following table:
HEAT OUTPUT
Provitherm 28 KTV
kW (Btu/hr)
n1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.0 (37 532)
n2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13.0 (44 356)
n3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16.0 (54 592)
n4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18.0 (61 416)
n5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20.0 (68 828)
n6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22.0 (75 064)
n7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24.0 (81 888)
n8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26.0 (88 712)
n9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27.6 (94 171)
n– . . . . . . . . . . . . . . . . . . . . . . . . . 27.6 (94 171) .. max. output
•Press Bar/Mode button to save and return to main menu.
Diagram 12
Diagram 13

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A
Note: DO NOT use a wire or sharp instrument on the holes.
Heat exchanger
• Locate the heat exchanger inside the sealed chamber.
• Gain acces to heat exchanger by removing fan and flue hood.
• Examine heat exchanger for any blockages or build up of deposits.
• Clean heat exchanger with soft brush or vacuum cleaner.
Reassembly of parts removed for servicing
All parts are replaced in reverse order to removal.
Flue system
• Check externally to make sure that flue is not blocked.
• Inspect flue system to make sure that all fittings are secure.
Operation of fan
• Switch on electrical supply and turn on gas.
• Remove sealed chamber cover.
• Light burner by operating external controls (if fitted) to call for heat.
• Check that fan operates when burner lights and stops when it goes out.
REPLACEMENT OF PARTS
To gain access to the boiler components, proceed as follows:
• Isolate boiler from electrical supply.
• Remove outer case, if necessary sealed chamber cover, combustion chamber cover
and side covers, see ‘Routine cleaning and inspection’
• Gently squeeze metal clip securing the control panel
box, lift it up and hinge down.
To replace fan
• Disconnect power supply and earth leads to fan.
• Supporting fan, unscrew and remove screw (A) se-
curing fan.
• Gently ease fan by pushing down and out of boiler.
• Fit replacement fan in reverse order to removal mak-
ing sure that mounting plate engages correctly onto
flue hood
Important: Ensure that fan outlet is correctly fitted into
flue elbow at top of boiler.
To replace air pressure switch
• Locate air pressure switch in upper left hand corner of sealed
chamber.
• Pull off clear plastic tube from base of switch.
• Remove electrical connections from the switch.
Important: Mark the connectors – it is necessary they have to be connected in the same
position.
• Unscrew and remove two screws securing switch to upper panel and remove switch.
• Fit replacement switch in reverse order to removal.
• Fit electrical connections to replacement switch.
• Refit clear plastic tube to switch connection L.
Note: If the fan will not run after switch on the boiler, the order of connections is probably
incorect.
Diagram 17
Diagram 15
SERVICING INSTRUCTIONS
To ensure the continued efficient and safe operation of the boiler, it is recommended that
it is checked and serviced at regular intervals. The frequency of servicing will depend
upon the installation conditions and usage but, in general, once a year should be
enough.
It is the law that any servicing is carried out by a competent person.
ROUTINE CLEANING AND INSPECTION
• Operate boiler and check for any faults that need to be put right.
• Isolate boiler from the gas and electrical supplies.
• On completion check all gas carrying parts for sound-
ness with leak detection fluid.
Remove boiler casing as follows:
Outer casing
• Undo screw securing the casing underneath boiler
and remove outer casing by pulling forwards, lifting
it up and off.
Sealed chamber
• Unclip two clips holding sealed chamber cover to
boiler, unscrew two screws in middle of the cover
and lift it forwards and off.
Side covers
• Undo 3 screws securing each of side covers and re-
move outer covers by pulling to side, forwards and off.
Cleaning the burner
• Unscrew and remove 6 screws securing combustion chamber cover and remove
cover.
• Disconnect flame sense electrode at burner.
• Disconnect ignition lead at gas valve module.
• Disconnect ignition earth lead.
• Undo nuts (A) securing gas supply pipe be-
tween burner and gas valve and remove pipe,
see diagram 16.
Note: The washer between the burner and burner
gas supply must be kept to use on reasembly.
• Unscrew 2 screws (B) securing burner to base
of sealed chamber.
• Pull main burner up and forward out of boiler.
• Examine and clean burner as necessary.
Diagram 16

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To replace safety valve
• Drain down heating circuit of boiler as described previously.
Simplification: for simpler work remove gas valve module and pump as described
previously.
• Remove expansion vessel hose from hydraulic block.
• Remove draining pipe from safety valve and unscrew safety valve.
• Fit replacement safety valve in reverse order to removal.
Important: Seal the safety valve thread by jointing compound.
To replace domestic heat exchanger
• Drain down heating circuit of boiler as described previously.
Drain down hot water circuit of boiler as follows:
• From below boiler, close cold water inlet isolating valve.
• Open a hot tap to drain hot water circuit.
• Remove gas valve.
• Unclip pump and pull forwards.
• Disconnect expansion flexible hose at connection to vessel fixing.
• Remove fixing screws and plate exchanger over hydraulic block.
• Fit replacement heat exchanger in reverse order to removal, ensuring seals are cor-
rectly positioned in hydraulic block.
• Open isolating valves on flow and return connections, refill, vent and pressurise
boiler. Check for leaks.
• Open cold water isolating valve. Check for leaks.
To replace overheat thermostats
Important: Isolate boiler from electrical supply before
this operation – connections to overheat thermostats
are mains voltage.
• Locate overheat thermostat (a) to left hand side of
sealed chamber, see diagram 20.
• Unclip thermostat from pipe.
• Pull off electrical connections from thermostat.
• Fit replacement thermostat in reverse order to remov-
al.
Note: No heat sink compound is required. The polarity
of the connections is not important.
To replace heating water thermistor
• Locate thermistor (b) clipped onto flow pipe to left hand side of
sealed chamber below overheat thermostat, see diagram 20.
• Unclip thermistor from pipe.
• Pull off electrical connections from thermistor.
• Fit replacement thermistor in reverse order to removal.
Note: No heat sink compound is required.
The polarity of the connections is not important.
To replace hot water thermistor
• Pull off electrical connections from thermistor and unscrew thermistor from left part of
hydraulic block.
• Remove gas valve module as described previously.
• Fit replacement thermistor in reverse order to removal.
Note: The polarity of the connections is not important.
To replace gas valve module
• Locate gas valve module attached to side of gas valve,
see diagram 18.
• Unscrew screws (a) and (b) securing cover onto gas
valve module.
• Remove cover and disconnect multi-plug from module.
• Disconnect ignition and flame sense leads from mod-
ule and withdraw module from gas valve.
• Fit replacement module in reverse order to removal.
• Reconnect ignition and flame sense leads, the con-
nections are uniquely sized to ensure correct replace-
ment.
• Refit cover ensuring all sealing grommets are correctly
located in module body.
To replace gas valve
• Ensure that gas supply is turned off at gas cock.
• Unscrew screw (a) and remove gas valve module.
• Undo nuts securing gas supply pipe be-
tween burner and gas valve and remove
pipe, taking care not to lose sealing wash-
ers, see diagram 18.
• Remove gas inlet connection to boiler.
• Unscrew 2 screws securing gas
valve to boiler bottom.
• Remove gas valve by lifting up-
wards and out of boiler.
• Fit replacement gas valve in re-
verse order to removal.
• Check for gas-tightness.
To replace burner
• Remove burner as described in ‘Cleaning the burner’.
• Fit replacement burner in reverse order to removal.
• Check if the injectors are correct.
To replace pump
Drain down heating circuit only of boiler as follows:
• From below boiler, close isolating valves on flow and return connections to boiler.
• Open boiler drain valve on left hand side of hydraulic block.
Note: It is not necessary to drain down entire heating circuit to carry out this work.
Simplification: for simpler work remove gas valve module and right side cover.
• Disconnect pump cable.
• Remove 2 clips fixing pump, see diagram 19.
• Unscrew 2 screws securing the pump to boiler bottom.
• Lift up the pipe and remove pump by lifting forward and out of boiler.
• Fit replacement pump in reverse order to removal.
• Open isolating valves on flow and return connections,
• Refill, vent and pressurise boiler. Check for leaks.
Diagram 18
Diagram 19
Diagram 20

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SCHEMATIC WIRING DIAGRAM
Diagram 23
Diagram 22
To replace printed circuit board (PCB)
Important: Isolate boiler from electrical supply before this operation.
• Gently squeeze metal clip securing the control panel box, lift it up and hinge down.
• From behind control panel box, unscrew and remove 4 screws securing PCB cover to
panel.
• Pull off electrical plugs from PCB.
• Remove 4 screws securing PCB to panel and lift out PCB.
• Fit replacement PCB in reverse order to removal.
To replace display and control panel board
Important: Isolate boiler from elec-
trical supply before this operation.
• Remove PCB cover as described
in ‘To replace PCB’.
• Pull off electrical plug of display
(A) from PCB, see diagram 21.
• Remove 4 screws securing PCB
to panel and lift out PCB.
• Remove 4 screws securing dis-
play and control panel board to
panel and gently lift it out.
• Fit replacement display and con-
trol panel bord in reverse order
to removal.
To replace pressure gauge
• Drain boiler as described in ‘To replace pump’
• Unclip pressure gauge clip and pull it out.
• Disconnect pressure gauge cable.
• Fit replacement pressure gauge in reverse order to removal.
To replace heat exchanger
• Drain down heating circuit of boiler only
as described previously.
• Remove sealed and combustion cham-
ber covers and side cases as described
previously.
• Remove overheating termostats from
heat exchanger pipes.
• Pull off spring clips securing heat ex-
changer pipes to heat exchanger.
• Manoeuvre heat exchanger pipes down
to disengage from heat exchanger.
• Gain acces to heat exchanger by remov-
ing fan and flue hood.
• Remove heat exchanger by sliding for-
ward and out of boiler.
• Fit replacement heat exchanger in reverse order to removal.
• Open isolating valves on flow and return connections, refill, vent
and pressurise boiler. Check for leaks.
Diagram 21

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F2 Central heating thermistor Check if flow thermistor is not
failure disconnected or short-circuited
Sensor Ohm resistance
10 kΩby 25°C, 12,7 kΩby 20°C,
16 kΩby 15°C
CH water temperature Check if system is not frozen
below 3°C
F3 Heat exchanger blockage Check main heat exchanger Boiler shuts down and
Check domestic heat pump runs
exchanger
F4 Domestic hot water Check thermistor/leads Domestic hot water is
thermistor faulty Sensor Ohm resistance: available bur poor
10 kΩby 25°C
12,7 kΩby 20°C
16 kΩby 15°C
F5 A defect of the Check the sensor’s The boiler provides
external sensor connection heating with constant
Check the sensor temperature of
heating water as
preset in the CHW
mode
Air pressure switch failure:
If the fan and the pump is running but the boiler doesn’t light, check the air pressure
switch.
Blown fuses:
If the main switch is on and display does not light check the FUSE (1) T80mA, see
diagram 21.
If the display lights but the pump, the fan and the ignition module don’t work check the
FUSE (2) T1.6A, see diagram 21.
Warning message:
If the pressure in CH system drops to 0.8 bar the LED on the Bar/MODE button starts to
flash. This give you information that CH pressure is on the low limit and must be pres-
surised. Nevertheless the boiler works until the pressure drops to 0.6 bar – then boiler
shuts down and F0 is displayed.
DHW flow is poor
If DHW floor is poor or boiler does not start when hot water tap is open, check following:
Cold water supply pressure is at least 1 bar.
Check if the cold water filter or flow regulator (plastic ‘O’ ring) is not clogged.
FAULT FINDING
Before fault finding, make sure that:
-All gas cocks are open and there is an inlet gas pressure of 20 mbar (G 20)
-The heating system pressure is at least 1 bar.
-There is a permanent mains supply to the boiler
-The fuses on the PCB are intact.
-All external controls are correctly wired and calling for heat.
WARNING: Always isolate the boiler from the electrical supply before carrying out any
electrical replacement work. Always check for gas soundness after any service work.
Digital display shows:
-CH temperature (no decimal point displayed)
-DHW temperature (decimal point displayed)
-diagnostic error messages
-pressure in CH system
-boiler output setting
As soon as the mains switch is on the display shows for a very short time the version
of software used. It has no importance for boiler operation.
Diagnostic error messages
In the event of a fault the following diagnostic error messages will be displayed:
Message Fault Action Comments
F0 Loss of system water Refill system Pump runs for one
Check for leaks minute.
Boiler is restarted by
switching of main
switch.
Air lock in boiler Bleed boiler and system
Pressure sensor failure Check the pressure sensor
(Sensing inlet must not be clogged)
F1 No flame detected Check flame sense electrode
and connecting cable
Check ignition electrode
Check ignition unit on gas valve
Check fan operation
Overheating of the boiler Reset overheat thermostats If overheat Thermo-
Check the pump revolution stats are blocked,
boiler does not ignite
when starting

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PROVITHERM 28 KTV – CONVERSION TO LPG
Note: Conversion must only be carried out by a competent person
• Isolate boiler from the gas and electrical supplies.
• Remove boiler casing, sealed chamber and combustion chamber cover as describ-
ed in Installation/Servicing Instructions.
• Disconnect flame sense electrode.
• Disconnect ignition lead at gas valve module.
• Disconnect ignition earth lead.
• Undo nut securing gas supply pipe between burner and gas valve.
• Unscrew 2 screws securing burner to base of sealed chamber.
• Pull main burner up and forward out of boiler.
Note: The washer between the burner and burner gas supply must be kept to use in
reassembly.
• Fit new burner with marked diameter of injector ∅0.73 mm to the boiler in reverse
order to removal.
• Readjust the gas valve.
Gas Valve Adjustment
To adjust the minimum and maximum settings,
proceed as follows:
• Unlock the PCB box and swing it down
• Connect a manometer to the burner pressure
test point (b) on the gas valve
• Remove the modulator plastic cap protecting the
adjusting screw on the top of modulating coil
• Start the boiler in Domestic Hot Water mode to
reach max. capacity (hot water tap fully open)
• Adjust the gas valve maximum pressure Pmax
using nut (1) on the top of modulating coil. Turn
the nut (1) fully clockwise by means of spanner
No. 10 to reach Pmax (check on the manometer)
• Adjust the gas valve maximum pressure Pmin using red plastic screw on the top of
modulating coil.
• Disconnect the connector from the modulating coil to assure that boiler will operate
on minimum. Block the nut (1) in the fully clockwise position by means of spanner and
by means of screwdriver turn the red plastic screw (2). Turn clockwise to increase,
anti-clockwise to decrease. Check Pmin on the manometer.
• Connect the connector to modulating coil and check again the Pmax to be sure that
nut (1) didn’t move.
• Re-place the plastic cap cover on the modulator and disconnect manometer
• Check for gas soundness
• Replace the PCB box and all covers
• Stick the self-adhesive label (delivered with LPG conversion kit) bearing the informa-
tion about the gas type and the gas supply pressure on the visible place inside the boiler.
Provitherm 28 KTV Inj. diam. Pmin Pmax
G20 (20 mbar) 1.20 mm 2.5 mbar 14.0 mbar
G30 (29 mbar) 0.73 mm 4.9 mbar 27.5 mbar
G31 (36 mbar) 0.73 mm 4.9 mbar 36.0 mbar

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NOTES: