Venturi Replacement Kit
for PRESTIGE 399
3
Do not check for gas leaks with an open
flame. Use a bubble test. Failure to check for
gas leaks can cause severe personal injury,
death or substantial property damage
12. Reconnect the wires to the gas valve as shown
in Fig.4.
13. Reattach the air inlet elbow to the venturi.
14. Reposition the Control Module panel and reat-
tach the front jacket panel.
15. Turn power supply to the Prestige “ON” and
return the unit to service.
COMBUSTION TEST/ADJUSTMENT
The installer MUST perform a complete combus-
tion check to ensure the following combustion lev-
els are met at high and low input firing rates and the
burner is operating at optimum conditions.
The combustion testing and adjustments
must be performed by a qualified installer,
service agency or the gas supplier. All com-
bustion measurements must be perform with
calibrated equipment to ensure proper read-
ings and accuracy.
Failure to perform a complete combustion
test at both high and low input rates may
result in incomplete combustion and the pro-
duction of carbon monoxide, which can
cause severe personal injury, death or sub-
stantial property damage.
MCBA Instructions
1. Manually place the boiler into High fire mode
by pressing the MODE button with “+” button
simultaneously on the control panel display
while in the standby (STBY) mode.
The control panel will display an H followed
by the current boiler temperature when
placed into High fire test mode.
2. If the combustion levels during High fire are
outside the recommended combustion settings
adjust the THROTTLE SCREW (see Fig. 4) as
follows:
Counter-clockwise adjustment of the THROT-
TLE SCREW at high fire:
O2 decreases and C02 increases
Clockwise adjustment of the THROTTLE
SCREW at high fire:
O2 increases and CO2 decreases
Table 1: Recommended Combustion Levels
3. Once the combustion level is set at High fire,
manually place the boiler into Low fire mode by
pressing the MODE button with “-” button
simultaneously on the control display while in
the standby (STBY) mode.
The control panel will display a L followed
by the current boiler temperature when
placed into low fire test mode.
WARNING
WARNING
NOTICE
WARNING
NOTICE
Natural Gas
Propane
O2 Min.
2.30%
3.70%
O2 Max.
5.30%
5.20%
CO2 Min.
8.80%
10.00%
CO2 Max.
10.50%
11.00%
CO Max.
100 ppm
100 ppm
