Check The Combustion Air Pressure - PEERLESS Combi 160 Installation, Operation & Maintenance Manual

11 - OPERATING
Figure 33 - Combustion air pressure probes
Figure 34 - Checking the combustion air pressure
11.8 - Check the
combustion air pressure
The boiler has a factory-set air/gas ratio. The pressure
of the gas at the burner is indirectly controlled by the
blower. The combustion air pressure must be checked
as follows while refering to fi gures 33 and 34:
1. use a differential manometer with a precision of at
least 0.1 in.W.C. (0.25 mbar);
2. close the manual gas shut off valve, fi gure 13 item
"3";
3. open the boiler casing following section 13.2;
4. press the two plastic spring tabs labeled "B" shown
in fi gure 18 and rotate the electrical box;
5. remove plug "B";
6. turn pressure probe screw "C" one turn
counterclockwise;
7. insert tube "F", from the negative side of the
manometer, through the opening of plug "B", and
connect it to pressure probe "C" as shown in fi gure
34;
8. remove plug "A" from the pressure probe and
connect the differential positive side of the
manometer to it;
9. the manometer connections must be made as
shown in fi gure 34, to get the correct pressure
reading;
10. replace panel "H" of fi gure 40 and latch it closed.
If panel "H" is not properly in place the manometer
reading will not be accurate;
11. turn the power switch to on, item "34" in fi gure 1;
12. press the
than 10 seconds, until a blinking
13. the combustion blower will run at maximum speed
for 10 minutes. During this time the burner will not
light;
14. compare the pressure on the manometer with the
table in section 14, "Combustion air pressure".;
15. if the combustion air pressure is too low, check
that there are no obstructions in the combustion air
and vent systems. Also make sure that panel "H" is
properly sealed;
16. if the combustion air pressure is within tolerance
press the button to return the boiler to its
normal running mode;
17. once the combustion air pressure check has
been performed, disconnect the manometer, close
pressure probe screw "C", close the boiler casing,
turn the manual gas shut off valve on and proceed
with the check and adjustment of CO2, section 11.9.
41
and keys together for more
is displayed;