Gas Settings; Check The Operational (Working Gas Inlet Pressure And Gas Rate); Combustion Parameters - Baxi 224 Combi 2 Installation And Service Manual

7 Commissioning
7.4

Gas settings

Fig.46 Gas meter to valve
17-21 mbar
Fig.47 Gas inlet test point
Fig.48 Type of fittings —
flue gas measuring point
A
B
A
44 Combi 2
A
18-22 mbar
19-23 mbar
PN-0000361
7.4.1 Check the operational (working gas inlet pressure and
gas rate)
Note
If the pressure drops are greater than shown in the diagram oppo­
site, a problem with the pipework or connections is indicated. Per­
missible pressure drop across system pipework ≤ 1mbar. Carry
out chimney sweep.
See
Checking combustion - chimney sweep mode, page 49.
With the boiler operating in the maximum rate condition check that
1.
the operational (working) gas pressure at the inlet gas pressure test
point is in accordance with BS 6798 & BS 6891. This must be AT
LEAST 18mb !
Ensure that this inlet pressure can be obtained with all other gas ap
2.
pliances in the property working. The pressure should be measured
at the gas test point on the gas inlet (A).
Measure the gas rate — With any other appliances & pilot lights
3.
turned OFF the gas rate can be measured.
The gas rate can be found in section 3. Technical specifications.
7.4.2

Combustion parameters

The boiler has two dedicated sockets in order to measure the combustion
efficiency and cleanliness of the combustion exhaust gases during
operation. One socket is connected to the flue gas exhaust circuit (A)
which is used to detect the cleanliness of the combustion exhaust gases
and the combustion efficiency. The other is connected to the combustion
air intake circuit (B) which is used to check for the possible recirculation of
the combustion exhaust gases in the case of coaxial pipes. The following
parameters can be measured when using the socket connected to the flue
gas circuit:
temperature of the combustion exhaust gases;
concentration of oxygen O
concentration of carbon monoxide CO.
The temperature of the combustion air must be measured using the socket
connected to the air intake circuit (B), inserting the measurement probe
approx. 7 cm.
In order to analyse the combustion exhaust gases, the chimney sweep
function must be activated, as described below.
or alternatively carbon dioxide CO
2
;
2