Gas Valve Adjustment Procedure - Weil-McLain SlimFit 2 Series Manual

™
SlimFit
COMMERCIAL CONDENSING GAS
Startup — final checks
You must re-install the flue gas temperature sensor
to prevent flue gas spillage into the boiler enclosure.
Failure to comply could result in severe personal
injury, death or substantial property damage.

Gas valve adjustment procedure

DO NOT attempt to adjust the gas valve settings un-
less you are a qualified technician, and with the use of
calibrated combustion test instruments. Adjust the
valve settings only as needed to meet the combustion
values given in Figure 71.
1. This procedure is only necessary when combustion tests
indicate the need, as explained under "❏ Check flame &
combustion with instruments, page 80."
2. Boiler behavior that might indicate a need to check combus-
tion values at high fire (as per page 80) to verify boiler is in
adjustment include: difficulty igniting, poor flame stability at
low fire, combustion noise or high carbon monoxide values.
3. Combustion readings must be taken at both high fire and
low fire.
Adjust valve at high fire
1. Use the Control display to navigate to Manual test mode (see
Figure 66, page 72) and force the firing rate to High (high fire).
(See page 89 for proper instructions on forcing rates during
Manual Test Mode). After the boiler has had time to stabilize
and high-fire RPM value (see Figure 76, page 89) is reached,
take a CO reading.
2
a. See Figure 72 to adjust if necessary.
b. Remove the blue cover on the throttle screw opening with
a straight-bit screwdriver.
Make only small (1/8-turn) throttle screw adjust-
ments. Adjustment can be sensitive, especially on
propane. Navigate to DIAGNOSTICS — Manual
test mode (see page 89 for proper instructions on
testing).
If the CO is HIGH, turn the throttle screw CLOCKWISE to
2
lower the input. Allow the boiler to stabilize and
take another reading. Continue until the desired
CO value is achieved.
2
c. If the CO is LOW, turn the throttle screw COUNTER-
2
CLOCKWISE to increase the input. Allow the boiler to
stabilize and take another reading. Continue until the
desired CO value is achieved.
2
d. Re-install the blue cover on the gas valve.
Adjust valve at low fire
1. Lock the boiler into low fire using the Control module screen.
Verify that the blower rpm value is correct for low fire (see
Figure 76, page 89).
2. Check the combustion readings.
3. If results are acceptable at low fire, verify high fire readings
again. Restore firing rate to AUTO.
4. If combustion results are not acceptable, remove the cover
screw over the offset adjustment (see Figure 72). Navigate to
Part number 550-100-162/0815
—
-
FIRED WATER BOILER
(continued)
DIAGNOSTICS — Manual test mode (see page 89 for proper
instructions on testing).
5. Use a T40 Torx driver to adjust the setting. Rotate clockwise
to increase CO
Re-install the cover screw when completed.
6. Consult your local Weil-McLain representative if acceptable
results cannot be obtained for both high and low fire.
❏
Adjust and test boiler controls
1. Follow instructions in this manual to set and verify opera-
tion of the boiler controls.
❏
Check ignition system safety shutoff device
1. After the boiler has been installed, turn off the boiler.
2. Shut off the manual gas valve located on the gas line to stop
flow of fuel to the boiler.
3. Turn on the boiler. It will start the ignition sequence, but will
not light. After some time, the boiler will lockout, the display
screen will turn red, and the Control will flash "Ignition
Fault". It means that the boiler tried to ignite without success
for five (5) times and went into Lockout mode. This means
that the ignition system safety device worked properly.
4. Clear the Lockout condition by selecting "Manual Reset" in
the Diagnostic Menu.
5. Open the manual gas valve located on the gas line to resume
fuel supply to the boiler.
Boiler Manual Series 2
Throttle screw location (ONLY for use by
a qualified technician, using calibrated
combustion test instruments)
, rotate counterclockwise to decrease CO
2
.
2
81