Part number 550-100-305/0118
76
AquaBalance
TM
W
ALL
M
OUNT
GAS
-
FIRED
WATER
BOILER
—
Boiler Manual
30
(continued)
❏
Propane boilers — verify conversion
1. Verify boiler has been converted for propane, See page 12.
DO NOT attempt to mea-
sure gas valve outlet pres-
sure
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 propane,
requiring no field adjustment.
Attempting to alter or measure the gas valve outlet pressure
could result in damage to the valve, causing potential severe
personal injury, death or substantial property damage.
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
When entering Test mode operation the boiler will
fire without a call for heat.
1. To start create a demand for heat, open up a hot water faucet
or turning up the thermostat.
1. Enter
into
the
“
TEST
” Mode to check combustion on High
Fire and Low Fire.
2. To operate the boiler in test mode, press the CH
“-” and
“+”
keys together for 5 seconds (See Figure 99, page 74) to
activate the “
TEST
” mode.
3. The boiler lights at the maximum heating 100% rate dis-
played on the LCD display.
4. The high fire (large) flame symbol will be displayed once the
boiler has lit.
5. Use DHW “_” button to drop firing rate to low fire.
6. To exit the “
TEST
” mode, press the CH keys (Items 3 and
4 Figure 76, page 60) together for 5 seconds, or leave the
boiler to automatically switch off after 15 minutes or stop-
ping DHW flow.
7. This TEST procedure is used to check/adjust combustion
CO and CO
2
per specifications Figure 102, page 77 and
Figure 105, page 78.
8.
Insert combustion analyzer probe
— Remove the flue access
fittings/turn to remove (see Figure 41, page 33) from the flue
pipe and insert a combustion test probe.
9. Test for CO
2
(or O
2
) and for CO. The CO
2
values must comply
with or Figure 105, page 78. If results are acceptable, proceed
to step 7.
IF NOT
, follow the instructions under “Throttle
Screw Adjustment” on page 77 to set the throttle screw posi-
tion. See
WARNING
below.
10. Measure natural gas input for High and Low Fire:
a. Operate boiler 10 minutes. Turn off other appliances.
b. At natural gas meter, measure time (in seconds) required
to use one cubic foot of gas.
If combustion at either high or low fire is out-
side the range given in Figure 102, page 77 or
Figure 105, page 78, follow the procedure given
on below, “Setting the Air/Gas Ratio Valve” for
adjusting the throttle screw on the gas valve.
If throttle screw adjustment does not correct
the problem, then shut down the boiler and
contact your local Weil-McLain Technical Sup-
port. Throttle screw adjustment must be done
only by a qualified technician, using calibrated
test instruments. Failure to comply could result
in severe personal injury, death or substantial
property damage.
c. Calculate gas input:
3600 x 1000
= Btuh
number of seconds from step b
d. Btuh calculated should approximate input rating on
boiler rating label.
11. Use the control display to navigate to Manual Test mode (see
Figure 99, page 74) and force the firing rate to LOW (low fire).
Push DHW “-” button only to drop to low fire.
12. Look at the flame through the flame inspection window. The
low fire flame should be stable and evenly distributed over
burner surface with a uniform orange color.
13. If combustion testing in low fire meets the specification
range - Exit “
TEST
” Mode by pressing the CH “+” and “-”
keys together for 5 seconds.
14. Reinstall the flue access fittings, (see Figure 41, page 33) used
for combustion analyzer probe and lock it in closed position.
You must reinstall the flue access fittings to the flue
adapters, to prevent flue gas spillage from the vent
adapter test ports . Failure to comply could result in
severe personal injury, death or substantial property
damage.
Table 2
Gas rate Combi and Heating Only boilers.
Gas Rate
(Natural Gas)
After 10 minutes from cold
Boiler
model
Maximum rate
Minimum rate
ft
3
/h
ft
3
/h
WMB-80
78.4
7.8
WMB-120
117.6
11.8
WMB-155
151.9
15.2
