55
IGNITION AND REGULATION WITH GAS (METHANE)
N.B. See the last pages for a specific description of the procedure for regulating the gas supply according to the
type of valve fitted to the burner.
1) Make sure the combustion head enters the furnace as far as that required by the boiler manufacturer.
Make sure that the device which shuts off the air to the combustion head is in the right position to deliver the
required fuel (the air gap between the disc and the head must be considerably reduced for low fuel delivery. For
high fuel delivery the air gap between the disc and the head must be relatively open). See the chapter “Adjusting
the combustion head”.
2) If this has not already been done when the burner was connected to the gas piping, all air must be bled from the
piping with the relative precautions and with doors and windows open. Open the union on the piping near the
burner, then open the gas cut-out ball cock(s) slightly. Wait until the characteristic smell of gas is noticed, then
close the ball cock. Wait, according to the specific conditions, until the gas has left the room, then reconnect the
burner to the gas piping.
3) Make sure there is water in the boiler and that the gate valve of the system are open.
4) Make absolutely sure that the flue products can be discharged freely (boiler and flue dampers open).
5) Make sure the voltage of the electrical supply to which the machine is to be connected matches that required for
the burner, and that the electrical connections (motor and main line) are arranged for the available voltage. Also
make sure that all electrical connections made on the site are correctly executed according to our wiring diagram.
Open the thermostat circuit of the second flame. The thermostat must not be connected, to prevent the second
flame from being activated while adjusting the first flame.
6) With the switch for the burner panel at position “0”, and the main switch on, manually turn off the remote switch to
check that the motor turns in the correct direction. If necessary invert the two wires feeding the motor to change
the direction of rotation.
7) Attach a pressure gauge with a suitable scale to the pressure point provided on the gas pressure switch (required
pressure permitting, it is preferable to use a water column instrument - for low pressures do not use instruments
with pointers).
8) Open the air regulator as far as deemed necessary (see BT 8653/1), and open the air gap between the disc and
head by about one third.
9) Operate the regulators on the safety valve and the “first flame” to enable the required gas delivery
(starting delivery).
N.B. See the last pages for a specific description of the procedure for regulating the gas delivery according
to the type of valve fitted to the burner.
10) Now turn on the control panel switch. The control unit is now powered and the programmer determines burner
activation as described in the chapter “Description of Operation”. During the pre-ventilation phase, make sure the
pressure switch that controls the air pressure changes over (from the closed position without detecting any pressure,
it must change to the closed position, with the detection of air pressure). If the air pressure switch does not detect
sufficient pressure (does not change over) the ignition transformer or the gas valves will not be turned on, and the
unit will shut down “cut-out”. When first ignited the unit may “cut-out” continuously due to the gas piping not having
been sufficiently bled, hence the amount of gas is insufficient to provide a stable flame. The valves do not open
altogether and the gas delivery is limited by the position at which the flow regulator incorporated into the first (pilot)
flame valve, was set manually.
11) With the burner lit and at minimum, immediately check the size and appearance of the flame visually.
Make all necessary corrections by adjusting the gas and air delivery regulators (see points 8 and 9). Subsequently,
check the quantity of gas delivered by reading the meter (see the chapter “Reading the meter”).
If necessary, correct the gas and relative combustion air delivery as described above (points 8 and 9).
12) Make sure that combustion occurs correctly, using the relative instruments. Carbon monoxide (CO) maximum
allowed = 0.1%, with a carbon dioxide (CO
2
) content of between 8 - 10 % for methane.
13) After adjusting, switch the burner off and on a number of times to make sure that it ignites correctly.
14) With the burner disconnected by the main switch, make a bridge between the terminals on the thermostat of the
second flame. Set the air to the position required for including the second flame (see BT 8653/1).
Open the
gas flow regulator incorporated into the second valve to allow a delivery deemed necessary for the main flame.