Sime RX Series User manual

RX
IT ES GB GR
PT

INSTALLER INSTRUCTIONS
CONTENTS
1 DESCRIPTION OF THE BOILER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
2 INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
3 CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
4 USE AND MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
IMPORTANT
When carrying out commissioning of the boiler, you are highly recommended to perform the following checks:
Make sure that there are no liquids or inflammable materials in the immediate vicinity of the boiler.
Make sure that the electrical connections have been made correctly and that the earth wire is connected to a
good earthing system.
Open the gas tap and check the soundness of the connections, including that of the burner.
Make sure that the boiler is set for operation for the type of gas supplied.
Check that the flue pipe for the outlet of the products of the combustion is unobstructed.
Make sure that any shutoff valves are open.
Make sure that the system is charged with water and is thoroughly vented.
Check that the circulating pump is not locked.
Purge the system, bleeding off the air present in the gas pipe by operating the pressure relief valve on the gas
valve inlet.
ENGLISH

45
1 DESCRIPTION OF THE BOILER
1.1 INTRODUCTION
The new series of “RX” gas-fired hea-
ting boilers has been designed and
manufactured to ensure maximum
user-friendliness and to ease both the
installation and the maintenance ope-
rations for the installer.
They comply with the european directi-
ves 90/396/CEE, 89/336/CEE,
92/42/CEE, 73/23/CEE and the
europen specification EN 297.
These appliances can be fired by natu-
ral gas (methane) and butane gas
(G30) or propane gas (G31).
This manual contains the instructions
for the following boiler models:
“RX 19÷55 CE” with piezoelectric
ignition
“RX 19÷55 CE IONO” with electro-
nic ignition and flame ionization
“RX 19-2 PVA CE” with pump,
expansion vessel and piezoelectric
ignition
“RX 19-2 PVA CE IONO” with
pump, expansion vessel, electronic
ignition and flame ionization.
The instructions given in this manual
are provided to ensure proper installa-
tion and perfect operation of the
appliance.
1.2 DIMENSIONS
1.2.1 “RX 19-2 ” versions
1.2.2 Versión “RX 37÷55”
Fig. 1
Fig. 1/a
R C.H. return 11/2”
R1 C.H. return (“PVA” vers.) 1”
M C.H. flow 11/2”
G Gas connection 1/2”
C1 Filling connection 1/2”
19 2
P mm 595 720
D mm 130 150
R C.H. return (“37-48” vers.) 11/2”
C.H. return (“55” vers.) 11/4”
M C.H. flow 11/2”
G Connection gas 3/4”
C1 Filling connection 1/2”
37 48 55
P mm 670 770 870
H mm 1435 1435 1675
Z mm 245 295 345
D mm 180 180 200

46
1.3 TECHNICAL FEATURES
19 2 37 48 55
Heat output kW 22,0 30,5 39,1 48,8 60,7
kcal/h 18.900 26.200 33.600 42.000 52.200
Heat input kW 25,0 34,8 44,8 55,0 69,2
kcal/h 21.500 29.900 38.500 47.300 59.500
Number of sections 34567
Water content l1013161922
Power consumption W
5-16*-100** 5-16*-100** 5-16* 5-16* 5-16*
Maximum water head bar44444
Maximum temperature °C 95 95 95 95 95
Loss of head
Water (∆t 30°C) mbar 2,0 3,0 4,5 5,5 10,3
Expansion vessel
Water content l 8 10
Preloading pressure bar 1 1
Smokes temperature ° C 119 118 110 13 0 141
Smokes flow gr/s 24,7 34,7 52,2 53,1 59,2
Category II2H3+ II2H3+ II2H3+ II2H3+ II2H3+
Type B11BS B11BS B11BS B11BS B11BS
Weight kg 101-113** 126-138** 150 176 202
Main burner nozzles
Quantity n° 22333
Methane ø mm 3,15 3,65 3,40 3,90 4,05
G30 - G31 ø mm 1,80 2,10 1,95 2,20 2,45
Pilot nozzles
Methane ø mm 0,29 0,29 0,29 0,29 0,29
G30 - G31 ø mm 0,24 0,24 0,24 0,24 0,24
Gas consumption ***
Methane m3s/h 2,64 3,68 4,73 5,82 7,32
Butane (G30) kg/h 1,97 2,74 3,53 4,34 5,45
Propane (G31) kg/h 1,94 2,69 3,47 4,27 5,37
Burner gas pressure
Methane mbar 9,8 9,6 9,6 9,1 11,5
Butane (G30) mbar 28 28 28 28 28
Propane (G31) mbar 35 35 35 35 35
Gas supply pressure
Methane mbar 20 20 20 20 20
Butane (G30) mbar 30 30 30 30 30
Propane (G31) mbar 37 37 37 37 37
* “IONO” vers. ** “PVA” vers. *** The gas consumptions refer to the calorific value at standard conditions at 15°C - 1013 mbar

The boiler should be installed in a fixed
location and shall be carried out only by
specialized and qualified firms in com-
pliance with all instructions contained
in this manual.
2.1 BOILER ROOM
AND VENTILATION
There are no particular regulations to
follow with reference to the boiler
room because “RX 19-2 ” boilers,
which do not exceed the 35 kW limit,
can be installed in rooms that are suf-
ficiently ventilated.
The rooms where the gas-fired
systems are installed must receive at
least the quantity of air necessary for
the normal combustion of the gas used
by the various installations.
Therefore, to ensure the air circulation
in the rooms, it is necessary to make
some holes in the walls.
These holes must have the following
characteristics:
Have e total free surface of mini-
mum 6 cm2for each kW of thermal
capacity, for a minimum of 100 cm2.
They must be located as close as
possible to floor level, not prone to
obstruction and protected by a
grid which does not reduce the
effective section required for the
passage of air.
The “RX 37÷55” models with a capa-
city exceeding 35 kW shall instead be
installed in a boiler room that meets
the existing safety regulations for
network gas-fired heating systems,
where minimum distances must be
observed.
2.2 BOILER CONNECTION
Before connecting the boiler circulate
some water in the pipes to eliminate
any foreign bodies which may prevent
the equipment from working properly.
When making the hydraulic connec-
tions, follow the instructions of fig. 1
carefully.
Connections shall be easily disconnec-
ted by means of unions with revolving
fittings. It is always advisable to mount
suitable interception gate valves on the
C.H. flow and C.H. return plant pipes.
The gas connection must be made
47
1.4 MAIN COMPONENTS
Fig. 2
KEY
1 Main switch
2 Lock out lamp (“IONO” vers.)
3 Smoke stat
4 Hydrometer
5 Thermometer
6 Safety stat (“IONO” vers.)
7 Air vent valve (“PVA” vers.)
8 Pump (“PVA” vers.)
9 Gas pilot tube
10 Drain cock (1/2”)
11 Pilot burner
12 Interrupted thermocouple
13 Piezoelectric ignition
14 Safety stat
15 Gas valve
16 Boiler stat
2 INSTALLATION

using seamless steel pipe
(Mannesmann type), galvanized and
with threaded joints provided with
gaskets, excluding three-piece connec-
tions, except for initial and end connec-
tions. Where the piping has to pass
through walls, a suitable insulating
sleeve must be provided.
When sizing gas piping, from the
meter to the boiler, take into account
both the volume flow rates (consump-
tion) in m3/h and the relative density of
the gas in question.
The sections of the piping making up
the system must be such as to gua-
rantee a supply of gas sufficient to
cover the maximum demand, limiting
pressure loss between the gas meter
and any apparatus being used to not
greater than:
1.0 mbar for family II gases (natural
gas);
2.0 mbar for family III gases (butane
or propane).
An adhesive data plate is sticked inside
the front panel; it contains all the tech-
nical data identifying the boiler and the
type of gas for which the boiler is
arranged.
2.2.1 Filter on the gas pipe
The gas valve is supplied ex factory
with an inlet filter, which, however, is
not adequate to entrap all the impuri-
ties in the gas or in gas main pipes.
To prevent malfunctioning of the valve,
or in certain cases even to cut out the
safety device with which the valve is
equipped, install an adequate filter on
the gas pipe.
2.3 CHARACTERISTICS
OF FEEDWATER
It is absolutely essential that the water
for the central heating system is to be
treated in the following cases:
Very extensive system (with high
contents of feedwater).
Frequent addition of makeup water
into the system.
Should it be necessary to empty the
system either partially or totally.
2.4 SYSTEM FILLING
The filling shall be made slowly so that
air bubles are eliminated through the
vents. The charge pressure, with the
system cold, must between 1 and 1,2
bar. The system loading pipe can be
connected with the 1/2” coupling on
the back header or, on the “PVA”
models, on the cross coupling connec-
ted to the expansion tank.
2.5 FLUE
A flue for the discharge into the atmo-
sphere of the products of combustion
of natural draught plants must have
the following characteristics:
be sealed against the products of
combustion, waterproof and insu-
lated;
be made of materials capable of
withstanding normal mechanical
stresses, heat and the action of the
products of combustion and their
condensate;
be vertical and with no narrowing
throughout its whole length;
be properly insulated to avoid flue
gases condensing or cooling, espe-
cially if it is placed outside a building
or in rooms with no heating;
be kept at a safe distance from com-
bustible and easily inflammable
materials by an air space or any
other suitable insulating material;
have a chamber collecting solid
materials and condensates below
the mouth of the first flue; this
chamber must be at least 500 mm
high. Access to this chamber must
be ensured through a hole with an
airtight metal door;
its inner section must be round, squa-
re or rectangular; if it is square of
rectangular, the corners must be
round and have a radius of 20 mm
minimum; however, hydraulically equi-
valent sections are also permitted;
be topped by a chimneypot having its
outlet outside the reflux area in
order to avoid back pressures which
may obstruct the free discharge of
flue gas into the air;
there must be no mechanical suc-
tion equipment at the top of the pipe;
there must be no overpressure in
stacks placed inside or adjacent to
inhabited rooms.
2.5.1 Flue connection
Fig. 3 refers to the boiler connection
to the flue or to the stack through flue
ducts. In making the connection obser-
ve the dimensions given and use sea-
ling materials capable of withstanding
mechanical stresses and flue heat
over time.
At any point of the flue the burnt gas
temperature shall not exceed the dew
point temperature. Maximum three
changes of direction can be made,
including the union to the stack/flue.
For changes of direction, use only cur-
ved components.
2. ELECTRIC CONNECTION
The boiler is equipped with an electric
cable with plug and shall be supplied
with 230 V - 50 Hz single-phase cur-
rent through a fuse protected switch
having a minimum distance of 3 mm
between the pins.
The room thermostat (class II accor-
ding to EN 60730.1), which should be
installed to ensure a good temperatu-
re control, must be connected to ter-
minals 1 and 4 after the existing brid-
ge has been removed.
NOTA: SIME refuses all responsibility
for damage to people or things due to
non-earthing of the boiler.
48
Fig. 3

49
KEY
IG Main switch
P Circulating pump (“PVA” vers.)
VG Gas valve
TI Interrupted thermocouple
TC Boiler stat
TS Safety stat
TA Room stat
TF Smoke stat
Fig. 4
NOTE: Where the circulating pump is
installed outside the boiler the electric
connection must be made on the termi-
nals 2 and 4 of the terminal board,
otherwise the pilot flame may go out
KEY
A FM 11 programmer
IG Main switch
TC Boiler stat
EA Ignition electrode
ER Ionisation electrode
P Circulating pump
TS Safety stat
EV1 Modulating coil
EV2 Modulating coil
TF Smoke stat
R Lock out lamp
TA Room stat
FA EMC filter
NOTE: When a room stat is to be fitted
remove the link between terminal 1
and 4 on the connector plug.
2. .1 “IONO” boiler wiring diagram
Fig. 4/a

3.1 ELECTRONIC IGNITION
The “IONO” boilers are equipped with
electronic ignition without pilot flame;
they are therefore equipped with an
electric control and protection device.
An electronic programmer, model
Brahma FM 11, controls the ignition
and the ionisation by means of two
electrodes as shown in fig. 5.
Maximum safety is garanteed because
in case of accidental extinction of the
burner the gas flow is stopped within 1
second. A reference mark made on
the burner ensures the proper applica-
tion of the ignition electrode.
3.1.1 Working cycle
Before lighting the boiler check with a
voltmeter that the electric connection
to the terminal board has been pro-
perly made observing the phase and
neutral positions of the wiring diagram.
Press the main switch on the control
board; the lamp will light if there is
power. At this stage the boiler will start
to work sending, via the FM 11 pro-
grammer, a discharge current to the
electrode and, at the same time, ope-
ning the gas valve. Normally the burner
takes 1 or 2 seconds to light.
It may however fail to light, in which
case the boiler lock-out lamp will be
activated. The main causes maybe:
No gas supply
The equipment performs regularly
sending voltage to the ignition elec-
trode that continues to spark for max.
10 seconds, without detecting the
burner starting, then it shuts down.
It may occur at the first starting or
when the boiler has not been used
for a long period of time and there is
air in the pipes. It may occur if the
gas cock is closed or if the winding of
one of the valve coils is interrupted,
thus preventing it from opening.
There is no spark
In the boiler you will only notice the
gas flow to the burner, after 10
seconds it shuts down.
It may be due to the fact that the elec-
trode cable is disconnected or is not
properly fixed to the terminal 10; or
the equipment transformer is burnt.
No ionisation
From the time of the starting you
can observe the electrode continuos
sparking even if the burner is on.
After 10 seconds the sparking stops
and so does the burner, while the
lock-out lamp appears to be on.
It occurs if the phase and neutral posi-
tion on the terminal board has not
been observed. The detection electro-
de cable is disconnected or the elec-
trode itself is earthed; the electrode is
very worn-out and needs replacing.
The sudden lack of voltage causes the
immediate shutdown of the burner and
when the voltage is restored the boiler
will automatically restart.
3.1.2 Ionization circuit
The ionization circuit shall be checked
with a normal microammeter, or even
better, with a digital microammeter
with a 0÷50 µA range.
The microammeter terminals shall be
electrically connected in series to the
ionisation electrode cable.
Under standard conditions the value
varies from 4÷6 µA. The minimum ioni-
zation current value, at which the
equipment may shut down, is approxi-
mately 1 µA. In this case it will be
necessary to check that there is a
good electric contact and to check the
wear of the electrode tip and of its
ceramic protection.
3.2 SMOKE SAFETY DEVICE
The smoke stat provides a protection
against the discharge of flue gas into
the atmophere (3 fig. 2).This control
device stops the gas valve if the flue
gas is descharged into the boiler room
is continuous way and in such quanti-
ties as to become dangerous.
To start the boiler again, switch off the
power, then remove the smoke stat
cover and reset the button below.
If the thermostat continues to trip off,
it will be necessary to check the flue
thoroughly, making all the necessary
changes to ensure it works properly.
On the “RX 37÷55” models, the
smoke stat capillary on the back of the
boiler shall be put into the 12.5 ø hole
of the droughtdiverter support bracket
and fixed to it with the fitting and the
M12 lock nut already mounted on the
capillary (fig. 6).
50
3 CHARACTERISTICS
KEY
1 Ionisation electrode support
2 Ionisation electrode
3 Ignition electrode
Fig. 5
KEY
1 Smoke stat capillary
2 M12 lock out
3 Capillary support bracket
4 M12 fitting Fig. 6

4.1 ADJUSTING GAS VALVE
“19÷55” VERSIONS
Standard “RX 19÷55 CE” and “RX 19-
2 PVA CE” boilers feature a
HONEYWELL V4600C gas valve (fig.
8). When the boiler is ignited for the
first time, it is always better to purge
the pipe by using the inlet pressure tap
(6) on the gas valve.
The pilot burner gas flow rate shall be
adjusted on the screw (4): to decrease
the pilot flame rotate the screw
clockwise; to increase the pilot flame
rotate the screw anticlockwise.
To adjust the main burner gas pressu-
re remove the plug on the pressure
regulator (2). The regulation is made
by rotating the screw under the plastic
plug with a screwdriver: rotate the
nylon screw anticlockwise to reduce
the pressure, clockwise to increase it.
51
3.3 SAFETY STAT
In case the boiler temperature
exceeds 95°C the safety stat (6-14 fig.
2), will extinguish the pilot burner thus
shutting off the gas flow to the pilot
and main burner.
“RX 19-2 ” models are equipped with
safety stat with automatic resetting,
and “RX 37÷55” with manual reset-
ting. Should the stat with manual reset-
ting trip off, it will be necessary to
unscrew the cover and reset the but-
ton below for the pilot burner to
restart.
3.4 CIRCULATING PUMP
PERFORMANCE CURVES
The “RX PVA” boilers can be equipped
with either EURAMO NYL 40/25 or
GRUNDFOS UPS 25/50 circulating
pumps.
Both have a built-in speed selector for
adjusting head and capacity.
Head and capacity performance cur-
ves of the standard circulating pump,
at different speeds, are given in fig. 7.
NOTE: Before starting the boiler
check that the circulating pump is
not locked.
00,5 4
3,532,521,51
Q (m3/h)
5
4
1
2
3
H (m)
1
2
3
EURAMO NYL 40/25 GRUNDFOS UPS 25/50
Fig. 7 Fig. 7/a
4 USE AND MAINTENANCE
KEY
1 Control button
2 Pressure regulator
3 Electric operator
4 Pilot burner adjusting screw
5 Outlet pressure tap
6 Inlet pressure tap
ON
OFF
Fig. 8

4.2 ADJUSTING GAS VALVE
“19-2 IONO” VERSIONS
Standard “RX 19-2 CE IONO” and
“RX 19-2 PVA CE IONO” boilers with
electronic ignition feature a SIT 830
TANDEM gas valve (fig. 9).
When the boiler is ignited for the first
time, it is always better to purge the
pipe through the pressure tap (3).
Remove the plug on the pressure regu-
lator (4) to adjust the main burner gas
pressure.
The regulation is made by rotating the
screw under the plug: rotate the screw
clockwise to increase the pressure,
anticlockwise to reduce it.
The valve can control a “soft” ignition of
the boiler through the screw (1).
Rotate the screw anticlockwise to
increase the burner “soft” ignition
pressure (STEP), clockwise to reduce
it. The optimum “soft” ignition values of
the burner depend on the type of gas:
Methane 3 - 4 mbar
Butane 6 - 7 mbar
Propane 6 - 7 mbar
4.3 ADJUSTING GAS VALVE
“RX 37÷55 CE IONO” VERS.
The electronically ignited “RX 37+55
CE IONO” boilers are equipped with
the HONEYWELL VR4605C gas valve
(fig.10).
When igniting the boiler for the first
time, it is always advisable to purge the
pipe by opening the inlet pressure tap
(3). To adjust gas pressure to the main
burner remove the plug on the pressu-
re regulator (5).
Use a screwdriver to regulate the
screw under the plug: to increase pres-
sure screw clockwise, to reduce it
screw counterclockwise.
4.4 ADJUSTING THE GAS
PRESSURE TO BURNERS
Pressure calibration and gas input are
carried out by the manufacturer.
During installation of the equipment,
feed pressure might be different from
standard values.
It is therefore necessary to check
pressure and gas input when igniting
the boiler for the first time.
This test should be performed with the
boiler in full operation (obviously no
other gas appliances should be
working at the same time). Read the
gas meter twice every 6 minutes.
Multiply the consumption by ten to cal-
culate the consumption per hour.
If this value does not correspond to the
one in point 1.3, turn the screw of the
pressure regulator on the valve until
the exact value is obtained.
Screw slowly and gradually.
Read the gas meter at least thirty
seconds after regulating the pressure.
4.5 GAS CONVERSION
A kit is supplied complete with the
necessary change-over materials for
operation with butane gas (G30) or
propane gas (G31). Operate in the fol-
lowing manner for changing over from
one gas to another:
Replace the main nozzles and pilot
nozzle supplied in a kit.
Remove the plug on pressure regu-
lator and tighten the adjusting
screw (2 fig. 8 - 4 fig. 9 - 5 fig. 10).
Set valve input pressure at 30/37
mbar according to the type of gas by
acting on the outer pressure reducer.
When the working pressures have
been adjusted, reseal the regulators.
After have ultimated the conversion
of the boiler, please stick onto the
casing panel the plate showing the
relevant feeding gas which is inclu-
ded into the kit.
NOTE: After assembling all the gas
connections, a test for gas tightness
must be carried out using soapy water
or special products. Do not use naked
flames. The conversion to different
gas must be carried out exclusively by
authorized technical personnel.
4. REMOVING THE CASING
It is possible to completely disassemble
the shell for an easy maintenance of
the boiler following these simple
instructions:
Remove the boiler top which is fixed
with pressure plugs.
Remove the panelboard.
To remove the door, unscrew com-
pletely the screw fixing the top hinge
and lift the door, removing it from
the fixed plug of the bottom hinge.
52
KEY
1 “Soft” igniter regulator
2 Outlet pressure tap
3 Inlet pressure tap
4 Main burner
adjusting screw
5 EV1 - EV2 coil
Fig. 9
KEY
1 EV1 coil
2 Outlet pressure tap
3 Inlet pressure tap
4 EV2 coil
5 Pressure regulator
Fig. 10

Remove front and back panels by loo-
sening the four nuts which fix them
to the panels side.
Remove the sides.
4.7 CLEANING AND
MAINTENANCE
When the heating is turned off at the
end of the season, it is compulsory to
check the boiler and clean it as follows:
Take off the boiler top.
Remove the smoke chamber cleaning
plate by unscrewing the fastening
screws in the “RX 19-2 ” boilers.
Remove the smoke chamber comple-
tely unscrewing the two nuts from
the back side and the nut from the
front side of “RX 37÷55” boilers.
Extract the burner assembly by
unscrewing the four screws which
fix it to the valve flange.
With the appropriate brush, reach
down to the rows of plugs of the cast
iron exchanger from the top and
scrape off any scale with vertical
movements.
Remove the burners from the nozzle
holder header and throw a jet of air
inside them so that any dust can be
removed. Make sure that the top
drilled part of the burners has no
scale left.
When disassembling and reassem-
bling the burners be careful not to
force any delicate parts, such as the
thermocouple drill or the ignition unit.
Scrape off any scale from the boiler
bottom and reassemble all the parts
checking the position of the gaskets.
Check the stack making sure the flue
is clean.
Check the correct operation of the
equipment.
After assembling all the gas connec-
tions, a test for gas tightness must be
carried out using soapy water or spe-
cial products. Do not use naked flames.
Maintenance and check of equipment
and safety devices should be carried
out at the end of each season only by
authorized technical personel.
4.8 FAULT FINDING
The pilot burner does not ignite.
- Make sure the gas inflow is regular
and that any air in the pipes has
been eliminated.
- Make sure the hole of the pilot nozz-
le is not blocked.
- Check ignition operations.
The igniter does no spark.
Replace the faulty piezoelectric igniter.
The electrode is misplaced or must
be replaced if broken.
Make sure there is no false contact
between terminal and igniter cable.
The pilot burner goes out when the
ignition button is released.
Make sure the pilot burner flame
covers the thermo-couple sufficiently.
Regulate gas capacity to the pilot.
Make sure the split thermocouple
terminals are well fixed to the
overheat stat.
The overheat stat is faulty and must
be replaced.
Replace the split thermocouple.
Replace the gas valve.
The pilot burner does not burn properly.
Check that the gas pressure is
regular.
Clean the main air inlet hole of pilot
burner.
Clean the pilot filter in the gas valve.
Light explosions when the burner
starts and delayed ignition.
Make sure the pilot burner flame is
not too short.
Make sure the boiler exchanger is
not too dirty.
The main burner does not ignite.
This means that the flue smoke stat
has tripped off (point 3.2)
Make sure power arrives to the gas
valve.
Replace the electric operator of the
valve.
Replace the valve.
The boiler reaches the set temperatu-
re, but the radiators do not heat up.
Make sure there are no air bubbles
in the system, if so purge from
appropriate air vents.
The room stat is too low or must be
replaced if faulty.
The connections of the room stat
are not correct. Make sure the
cables are placed on terminals 1
and 4 of the boiler terminal board.
The circulation pump is blocked,
unblock it.
The electric winding of the circulation
pump is faulty, replace the pump.
The boiler pressure relief valve opens
often.
Make sure the system cold water
pressure is not too high, follow the
suggested values.
If the pressure relief valve is faulty,
replace it.
Check pre-load pressure of the
expansion tank.
Replace the expansion tank if faulty.
The boiler gets dirty easily causing
scaling of cast iron exchanger and
cutting off of smoke stat.
Make sure the main burner flame is
well regulated and the gas con-
sumption is proportional to the boi-
ler output.
The boiler is installed in a poorly ven-
tilated room.
Insufficient flue draught or not com-
plying with existing standards
The boiler operates at too low tem-
peratures, set the boiler stat at
higher temperatures.
The thermostat re-ignites with too
high temperature drop.
Replace the boiler stat which is
faulty.
53

54
BOILER IGNITION
Follow these instructions to ignite the boi-
lers “RX CE” and “RX PVA CE” (fig. 11):
Press the gas valve (15) push button
hard and, simultaneously, push the
piezo igniter button (13) several times.
Keep the valve button pressed for
15-20 seconds, then release it
checking that the pilot burner (11) is
on. Should it switch off, repeat the
operation.
Switch the power on to make the boi-
ler operate.
On “RX IONO” and “RX PVA CE IONO”
models it is enough to switch on the
switch (1) to make the boiler operate
and begin heating.
ADJUSTMENT OF HEATING
TEMPERATURE
The heating temperature can be adju-
sted with the stat knob with a range
from 45ºC to 85ºC (16 fig. 11). The
temperature setting can be checked
on the thermometer (5 fig. 11). For an
always optimum operation of the boiler
we recommend not to reduce the ope-
rating temperature below 60ºC.
LOCK OUT RESET OF THE
CONTROL BOX
If, in the “IONO” models, the burner
does not ignite lock-out lamp will be
activated (2 fig. 11).
Press the resetting button to make
the boiler automatically start.
If, after trying to release the boiler
two or three times, this does not
regularly start, call on the authorized
technical personel.
SWITCHING OFF THE BOILER
To switch off the boilers “RX CE” and
“RX PVA CE” temporarily, it is enough
to turn the switch (1 fig. 11) to off, thus
clearing power to all electric devices;
only the pilot flame will keep burning.
To switch the boilers and their pilot
WARNINGS
In case of fault and/or incorrect equipment operation, deactivate it, without making any repairs or taking any direct
action. Contact the nearest Authorised Technical Service Centre.
The installation of the boiler and any servicing or maintenance job must be carried out by qualified personnel. Under
no circumstances, the devices sealed by the manufacturer can be tampered with (pr EN 89).
It is absolutely prohibited to block the intake grilles and the aeration opening of the room where the equipment is
installed.
USER INSTRUCTIONS
LIGHTING AND OPERATION
KEY
1 Main switch
2 Lock out lamp
(“IONO” vers.)
3 Smoke stat
4 Hydrometer
5 Thermometer
6 Safety stat (“IONO” vers.)
7 Air vent valve (“PVA” vers.)
8 Pump (“PVA” vers.)
9 Gas pilot tube
10 Drain cock (1/2”)
11 Pilot burner
12 Interrupted thermocouple
13 Piezoelectric ignition
14 Safety stat
15 Gas valve
16 Boiler stat
Fig. 11

55
flame off completely, it is necessary to
turn the gas valve button (15 fig. 11)
clockwise.
On “RX CE IONO” and “RX PVA CE
IONO” models with electronic ignition it
is enough to turn off the switch (1 fig.
11) to turn off the boiler. Close the gas
pipe cock if you are not going to use
the boiler for a long time.
SAFETY STAT
“RX 37÷55” models are equipped with
safety stat
(6 fig. 11) with manual
resetting.
In case the boiler tempera-
ture exceeds 95°C the safety stat will
extinguish the pilot burner thus shut-
ting off the gas flow to the pilot and
main burner.
Should the stat trip off, it will be neces-
sary to unscrew the cover and reset
the button below for the pilot burner to
restart (fig. 12).
Should the boiler “lock out” again,
you must call the authorized techni-
cal staff.
SMOKE SAFETY DEVICE
It is a safety device which controls the
correct discharge of flue gas into the
atmophere (3 fig. 11).
The control device stops the gas
valve if the flue gas is descharged into
the boiler room is continuous way and
in such quantities as to become dan-
gerous.
To start the boiler again, switch off
the power, then remove the smoke
stat cover and reset the button
below (fig. 12).
If the boiler stops again, it will be
necessary to call the authorized tech-
nical staff.
SYSTEM FILLING
Check periodically that the hydrometer
(4 fig. 11) has pressure values at a
switched-off system of 1 - 1,2 bar.
If the pressure is less than 1 bar, re-
charge it rotating the knob anti-clock-
wise. After the operation check that
the tap is properly closed.
Should the pressure exceed the fore-
seen limit, discharge the superfluous
amount by operating on the vent knob
of any radiator.
GAS CONVERSION
Should a gas other than that for which
the boiler is equipped be used, the con-
version has to be carried out by tech-
nical personel authorized by the manu-
facturer.
CLEANING AND MAINTENANCE
When the heating is turned off at the
end of the season, it is compulsory to
check the boiler and clean it.
Maintenance and check of equipment
and safety devices shall be carried
out only by authorized technical per-
sonel. The boiler is supplied with an
electric cable. Should this require
replacement, get in touch exclusively
with the authorized technical staff.
Fig. 12