Part number 550-142-058/0811
71
WM97+
gas
-
fired
water
boiler
—
Boiler Manual
Startup — final checks
(continued)
To start the boiler
1. Turn OFF the boiler ON/OFF switch.
2. Read and follow the Operating Instructions, Fig-
ure 75, page 72.
3. The control module display will show installed sensors when
first powered. Make sure the right sensors are detected and
the correct boiler model is identified. If not, determine the
cause and correct before proceeding.
If boiler does not start correctly
1. Check for loose connections, blown fuse or service switch off?
2. Are external limit controls (if used) open? Is boiler water
temperature above 200 °F?
3. Are thermostats set below room temperature?
4. Is gas turned on at meter and boiler?
5. Is incoming gas pressure less than the minimum values given
on page 14?
6. Are control module settings correct for the application?
7. Is the warm weather shutdown activated?
8. If none of the above corrects the problem, refer to Trouble-
shooting, beginning on page 82.
❏
Check system and boiler
❏
Check water piping
1. Check system piping for leaks. If found, shut down boiler and
repair immediately. (See WARNING on page 68 regarding
failure to repair leaks.)
2. Vent any remaining air from system using manual vents. Air
in the system will interfere with circulation and cause heat
distribution problems and noise.
❏
Check vent piping and air piping
1. Check for gas-tight seal at every connection and seam of air
piping and vent piping.
Venting system must be sealed gas-tight to prevent
flue gas spillage and carbon monoxide emissions
which will result in severe personal injury or death.
❏
Check gas piping
1. Check around the boiler and inside the boiler jacket for gas
odor following the procedure of page 44 of this manual.
If you discover evidence of any gas leak, shut down
the boiler at once. Find the leak source with bubble
test and repair immediately. Do not start boiler
again until corrected. Failure to comply could re-
sult in severe personal injury, death or substantial
property damage.
❏
Propane boilers — verify conversion
1. Verify propane orifice bushing has been installed. See page 12.
DO NOT attempt to mea-
sure gas valve outlet
pressure
DO NOT adjust or attempt to measure gas valve outlet
pressure. The gas valve is factory-set for the correct outlet
pressure. This setting is suitable for natural gas and pro-
pane, requiring no field adjustment.
Attempting to alter or measure the gas valve outlet pres-
sure could result in damage to the valve, causing potential
severe personal injury, death or substantial property
damage.
WM97+ boilers are shipped ready to fire natural gas
ONLY.
Failure to comply could result in severe personal injury,
death or substantial property damage.
❏
Check flame & combustion with instruments
1. Initiate a call for heat on one of the thermostat inputs.
2. Access the control module installer menus by pressing and
holding the UP and DOWN arrow keys for seven seconds.
3. Use the control module display to navigate to Manual test
mode (see Figure 69, page 64) and force the firing rate to
MAX (high fire).
4. Look at the flame through the flame inspection window.
The high fire flame should be blue and should be stable. The
burner surface should be covered with orange dots.
5. Remove the flue temperature sensor from the flue pipe and
insert a combustion test probe.
6. Test for CO
2
(or O
2
) and for CO. The CO
2
values must comply
with Figure 77, page 73. If results are acceptable, proceed to
step 7.
IF NOT
, follow the instructions under “Throttle screw
adjustment procedure” to set the throttle screw position. See
WARNING below.
If combustion at either high or low fire is
outside the range given in Figure 77, follow
the procedure given on page 73 for adjusting
the throttle screw on the venturi. If throttle
screw adjustment does not correct the prob-
lem, then shut down the boiler and contact
your local Weil-McLain representative.
Throttle screw adjustment must be done
only by a qualified technician, using cali-
brated test instruments. Failure to comply
could result in severe personal injury, death
or substantial property damage.
CONTINUED AFTER NEXT PAGE