20
Part Number 550-142-785/0812
GWI
Series 2
Gas-Fired Water Boilers –
Boiler Manual
❏
Boiler and heat distribution units filled with water?
❏
Automatic air vent, if used, open one full turn?
❏
Air purged from system?
❏
Air purged from gas piping? Piping checked for leaks?
❏
Correctly-sized manifold orifices installed? See
Table 3,
page 6
to check size and fuel type.
Correctly sized manifold orifices must be used.
Failure to do so will cause severe personal injury,
death or substantial property damage.
❏
Followed “Operating instructions” on boiler or in manual,
page
26
for proper start-up?
❏
Proper burner flame observed? See “Verify operation”, manual
Section 7.
❏
Test temperature limit — While burners are operating, turn
Boiler Temp adjustment knob counterclockwise until display
reading is below actual boiler water temperature. Burners
should go off while circulator continues to operate. Turn
Boiler Temp adjustment knob clockwise until display read
-
ing is above boiler water temperature and ignition sequence
should resume.
❏
Test additional field-installed controls — If boiler has a low
water cutoff, additional high limit or other controls, test for
operation as outlined by manufacturer. Burners should be
operating and should go off when controls are tested. When
controls are restored, burners should reignite.
❏
Test ignition system safety device:
a. Connect manometer to outlet side of gas valve. Start boiler,
allowing for normal start-up cycle to occur and main burn
-
ers to ignite. With main burners on, manually shut off gas
supply at manual main shutoff gas valve. Burners should
go off. Open manual main shutoff gas valve. Manometer
should confirm there is no gas flow. Pilot will relight, flame
sensing element will sense pilot flame and main burners
reignite.
❏
Set limit control(s) to system temperature requirements. Adjust
balancing valves and controls to provide design temperature
to system.
❏
Set Economy mode, fully clockwise.
❏
For multiple zones, adjust flow so it is about the same in each zone.
❏
Verify thermostat heat anticipator (if available) set properly?
See wiring diagram label on boiler or in manual, page 24 and
25.
❏
Cycle boiler with thermostat — Raise to highest setting and
verify boiler goes through normal start-up cycle. Lower to
lowest setting and verify boiler goes off.
❏
Cycle DHW Aquastat if used.
❏
Measure natural gas input:
a. Operate boiler 10 minutes.
b. Turn off other appliances.
c. At natural gas meter, measure time (in seconds) required
to use one cubic foot of gas.
d. Calculate gas input:
3600 x 1000
number of seconds from step
c
= Btuh
e. Btuh calculated should approximate input rating on boiler
8 Checkout procedure
Check burner flame — Pilot burner
Proper pilot flame (see
Figure 16
):
1. Blue flame.
2. Inner cone engulfing pilot flame sensor.
3. Pilot flame sensor glowing cherry red.
Improper pilot flame:
1. Overfired — Large flame lifting or blowing past pilot flame
sensor.
2. Underfired — Small flame. Inner cone not engulfing pilot flame
sensor.
3. Lack of primary air — Yellow flame tip.
Figure 17 Typical main burner flame
Verify operation
Figure 16 Typical pilot burner flame
4. Incorrectly heated pilot flame sensor.
Check burner flames — Main burner
Proper main burner flame (see
Figure 17
):
1. Yellow-orange streaks may appear (caused by dust).
Improper main burner flame:
1. Overfired — Large flames.
2. Underfired — Small flames.
3. Lack of primary air — Yellow tipping on flames (sooting will
occur).
7 Start-up
continued
