Product specifications

If the boiler's burner fails to ignite after 3 reset
attempts, re-purge the gas supply, using the inlet
pressure measurement nipple. Otherwise consult
the Atmos Heating Systems.
Ensure that the appliance is functioning
correctly by undertaking the following inspections
and noting the results and work carried out on the
Service Card (located on the front of the boilers
torage tank insulation shells):-s
1. Visual inspection of the combustion flame.
2. Measurement of the gas flow rate by stopwatch
& meter.
3. Measurement of either the O
2 or CO2
percentage concentration within the flue gases
by flue gas analysis.
4. Measurement of the CO/CO2 ratio.
5. Measurement of the gas inlet pressure.
The procedure required to undertake inspections
1, 2, 3 and 4 are detailed in Section 10 of these
instructions. The procedure for inspection 5 is as
follows:-
The measurement of gas inlet pressure must be
taken during burner operation at maximum heat
input via the measurement nipple provided on the
gas valve. (Fig 29). The gas inlet pressure reading
must be at least 20mbar.
Check the burner's gas rate by stopwatch and
meter. On the maximum input of 24kW, 32kW or
38kW (depending on boiler model), the time taken
to use 0.024 (0.847 ft³), 0.032 (1.130 ft³), or
0.0378 (1.335 ft³) of gas respectively should be
33 seconds (± 2seconds).
When timing 1 ft³ on the meter, the equivalent is 39
secs (24kW), 29 secs (32kW) or 25 secs (38kW).
When counting the litres over 2 min period for a
metric meter, this is equivalent to 87 litres (24kW),
116 litres (32kW), or 137 litres (38kW).
Set the room thermostat to its minimum setting.
Switch on the hot water heating by pressing the
hot water button. The 'On' indication light will
illuminate. The three-way valve will switch over to
the water heater position and the burner will ignite
to heat the stored domestic hot water. (status report
Code 1
).
Reset the room thermostat back to the desired
position.
Note!
If during the heating of the stored domestic
water, the room thermostat also makes a
demand for heating, the hot water and central
heating demand will be met simultaneously
(status report Code 4).
The following codes may also appear on the
diagnostic display during the commissioning
process:-
(1•) Heat demand water heater
(2•) Heat demand central heating
(3•) Heat demand water heater and
C/heating, priority water heater
heating
(4•) Heat demand water heater and
C/heating, supply to both.
8.4 System balancing.
For efficient boiler operation, the heating system
must be correctly balanced to ensure that all
radiators are heating up evenly and a required temp.
differential of about 20ºC is present between the
boiler's heating flow and return connections.
The required water flow rate through the appliance
is 0·8 m³/h, 1·2 m³/h and 1·5 m³/h. for the Atmos
Multi 24, 32 and 38 models respectively. The
maximum permissible system resistance to enable
the boiler pump to achieve these flow rates is 3m,
1·5m and 1·5m respectively. (Fig 30, noting that
only the 38 model has the RS15/7 pump).
Figure 30: Available pump outputs
ATMOS MULTI Mk 2 version 2008
Page 37