Check Flue Gas Temperature - Weil-McLain WM97+ Manual

WM97+ -
gas fired water boiler
Annual startup
Check blower speeds
1. For installations at altitudes above 5,500 feet, make sure the control
is set up for high altitude in the boiler setup menu. The control
module automatically adjusts low fire and ignition rates to com-
pensate for high altitude conditions.
2. For installations below 5,500 feet, high altitude should NOT be
enabled.
3. Use the control module display to navigate to DIAGNOSTICS/
Manual test mode (see Figure 60, page 55 for navigation instruc-
tions and Figure 69, page 64 for the complete Diagnostics menus).
4. Set the firing rate to MINIMUM (low fire).
5. Write down the blower RPM value shown and compare to the
value in Figure 81. The value should no less than the "Minimum
setting" and no higher than the Ignition "Factory setting" listed.
Low fire rate (and corresponding blower speed) is adjusted in the
boiler setup menu.
6. Set the firing rate to MEDIUM (ignition rate).
7. Write down the blower RPM value. It should be within 200 RPM
of the value listed in Figure 81.
8. Set the firing rate to MAXIMUM (high fire).
9. Write down the blower RPM value. It should be within 200 RPM
of the value given in Figure 81.
10. If any of the values are outside the ranges listed in the previous
steps, contact the factory for technical assistance.
Minimum and maximum blower speeds can be adjusted
within limits, but changing speeds will affect AFUE rat-
ings.

Check flue gas temperature

1. Set the boiler to high fire. Then adjust the control module display
to view flue gas temperature and boiler return temperature.
2. The flue gas temperature should be no more than 50°F higher than
the boiler return temperature.
3. If the flue temperature is higher than this, shut down the boiler,
allow to cool, and follow the procedure starting on page 91 to clean
the heat exchanger.
80
— Boiler Manual
(continued)
Figure 81 Firing rates and corresponding blower
speeds (low fire, ignition, and high fire)
— for altitudes up to 5,500 feet and high
altitude (above 5,500 feet)
WM97+ Model 70
% RPM Btu/Hr
Low fire
Minimum setting 20 1,100 14,000
Factory setting 33 1,675 23,100
High altitude 33 1,675 23,100
Ignition
("Medium" setting in manual test mode)
Factory setting 47 3,200 32,900
High altitude 62 3,500 43,400
High fire
(adjust if desired to match maximum system load —
High fire % rate = Max heat load / Boiler output)
(adjusting speed will affect boiler AFUE rating)
Factory setting 96 4,150 67,200
Maximum setting 100 4,300 70,000
Note 1 — The boiler will automatically derate the Btu
values listed in this table by 4% per 1,000 feet above
sea level.
110
% RPM Btu/Hr
Note 1 Note 1
20 1,400 22,000
33 2,150 36,300
33 2,150 36,300
47 2,800 51,700
62 3,500 68,200
96 5,450 105,600
100 5,650 110,000
Part number 550-142-058/0811