Chimney Sweep Function (Co2 Adjust); Combustion Adjustment Function; Check Firing Rate - UTICA BOILERS MAH-125 Installation, Operation And Maintenance Manual

9.10 Chimney Sweep Function (CO
For correct boiler operation, content of (CO
COMBUSTION TABLE
Nominal value
Maximum
power (100%)
Permitted value 8.2 – 9.3
Nominal value
Ignition power
(*)
Permitted value 8.2 – 9.3
Nominal value
Minimum
power (0%)
Permitted value 8.2 – 9.3
(*)
Automatically calculated from the PCB
Chimney Sweep Function enables boiler to generate maximum
heating power.
After activation, boiler power % can be adjusted from
minimum (0%) to maximum (100%) in DHW mode.
A. Press and hold and
seconds. When the function is enabled, displays shows
"On" for few seconds followed by program row "303"
alternating with % of boiler power.
B. Press to gradually adjust power (increments of
1%).
C. To exit press both buttons together for at least 6
seconds.
If value of CO -O
is different, check the electrodes and their
2
2
relative distances. See Figure 11-1.
If necessary, replace electrodes and position them correctly.
If problem persists, use "COMBUSTION ADJUSTMENT
FUNCTION (CO %)". See Section 11 General Maintenance,
2
Figure 11-1 Electrodes.
NOTICE
• Press to display instantaneous flow temperature for
15 seconds.
• Use a regularly calibrated combustion analyzer for
combustion analysis.
• During normal operation boiler performs combustion
control cycles. In this phase CO values higher than 400
ppm can occur for brief periods of time.
9.11 Combustion Adjustment Function (CO
This function sets out to partially adjust the value of CO
Use the following procedure:
1.
Press buttons and
When the function is enabled, displays shows "On" for a
few seconds followed by program row "304" alternated
with the % of boiler power;
9 - START UP PROCEDURE
Adjust)
2
- O ) in the combustion flue must be within tolerances indicated in table below.
2 2
Gas A Gas A
(Natural Gas) (Natural Gas)
MAH-125 MAC-150
CO2 % O2 % CO2 %
8.7 5.4 9.0
6.3 – 4.3 8.5 – 9.5
8.7 5.4 8.7
6.3 – 4.3 8.2 – 9.3
8.8 5.2 8.8
6.3 – 4.3 8.2 – 9.3
at the same time for 6
%)
2
together for at least 6 seconds.
Gas A
(Natural Gas)
MAH-165
O2 % CO2 % O2 %
4.9 9.0 4.9
5.7 – 4.0 8.7 – 9.3 5.4 – 4.3
5.4 8.7 5.4
6.3 – 4.3 8.2 – 9.3 6.3 – 4.3
5.2 9.0 4.9
6.3 – 4.3 8.7 – 9.3 5.4 – 4.3
2.
After burner is lit, boiler reverts to maximum DHW power
(100). When display shows "100" it is possible to partially
adjust value of CO
3.
Press and
function number "304" (
4.
Press
(from -3 to +3);
5.
Press to save new value. Power value "100" will show
on display again. Boiler continues operating at maximum
DHW power.
This procedure can be used to adjust CO
and minimum power by pressing
5 above.
6.
After saving the new value (step 5 above), press
to set boiler to ignition power. Wait for value of CO
to stabilize. Adjust as described in step 4 of procedure
(power value is a number <> 100 and <> 0). Repeat step
5 to save.
7.
to adjust boiler to minimum power. Wait for
Press
value of CO
value = 00);
8.
Exit function by pressing
6 seconds, see step 1.

9.12 Check Firing Rate

1.
Measure input, if a gas meter is installed in the system.
• Turn off gas to all other appliances.
%.
2
• Activate some heating zones to dissipate heat.
• Set boiler on high fire using Chimney Sweep Function.
• Use ½, 1 or 2 cu ft dial on gas meter. Measure time
required for two or more complete revolutions. Measure
for one or more minutes.
time
• Calculate input.
44
Gas A
(Natural Gas)
MAC-205
CO2 % O2 %
9.0 4.9
8.7 – 9.3 5.4 – 4.3
8.7 5.4
8.2 – 9.3 6.3 – 4.3
9.0 4.9
8.7 – 9.3 5.4 – 4.3
%;
2
. Display shows "00" alternating with
flashes);
to raise or lower the amount of CO
2
to stabilize. Go to step 4 to adjust (power
2
and
240011941 REV B, [03/31/2018]
Gas E (LPG)
CO2 % O2 %
10.0 6.0
9.5 – 10.5 6.8 – 5.2
10.8 4.8
10.3 – 11.3 5.5 – 4.1
10.0 6.0
9.5 – 10.5 6.8 – 5.2
2
to ignition power
after performing step
2
together for at least