Weil-McLain WM97+110, Manual, Page: 98 / 132

Part number 550-142-085/0712
WM97+
gas
-
fired water boiler
— Boiler Manual
– 98 –
Annual startup
(continued)
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 WM97+ control
automatically adjusts low fire and ignition rates to
compensate for high altitude conditions.
2. For installations below 5,500 feet, high altitude
should NOT be enabled.
3. Use the WM97+ control display to navigate to
DIAGNOSTICS/Manual test mode (see Fig-
ure 80, page 72 for navigation instructions and
Figure 89, page 81 for the complete Diagnostics
menus).
4. Set the firing rate to MINIMUM (low fire).
5. Write down the blower RPM value shown and com-
pare to the value in Figure 102. 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 102.
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 102.
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 chang-
ing speeds will affect AFUE ratings.
Check flue gas temperature
1. Set the boiler to high fire. Then adjust the WM97+
control 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 110 to clean the heat
exchanger.
Figure 102
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
70 110 155
% RPM Btu/Hr
Note 1
% RPM Btu/Hr
Note 1
% RPM Btu/Hr
Note 1
Low fire
Minimum
setting
20 1,100 14,000 20 1,400 22,000 18 1,300 28,000
Factory
setting
33 1,675 23,000 33 2,150 37,000 33 2,100 52,000
High
altitude
33 1,675 23,000 33 2,150 37,000 33 2,100 52,000
Ignition
(“Medium” setting in manual test mode)
Factory
setting
47 3,200 32,900 47 2,800 51,700 47 2,800 72,850
High
altitude
62 3,500 43,400 62 3,500 68,200 61 3,500 94,550
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 96 5,450 105,600 96 5,300 148,800
Maximum
setting
100 4,300 70,000 100 5,650 110,000 100 5,500 155,000
Note 1 — The boiler will automatically derate the Btu values listed in
this table by 4% per 1,000 feet above sea level.