Weil-McLain CGi Series 3 Installation And Maintenance Manual page 50

CG i
GAS- FIRED wATER BOILER- sERIEs 3 -
Boiler Manual
11
a
Troubleshooting - procedure
!&WARNING!
Label all wires prior to dis-
connection when servicing
controls. Wiring errors can
cause improper and danger-
ous operation.
Check the following:
I. Wire connectors to control module are securely plugged in at module and
originating control.
2. Air pressure S\vitch hoses are properly and securely plugged in and are not
damaged.
!&WARNING!
Never jmnper (bypass) roll-
out thermal fuse element
or any other device except
fo r momentary testing as
outlined in Troubleshoot-
Ing Charts. Severe personal
injury, death or substantial
property damage can result.
3.
Gas
pressures:
a.
With boiler off - 13" w.c. maximum natural or propane gas pres-
sure upstream of gas valve.
b. With boiler on:
s•
w.c. minimum natural gas pressure or 11" w.c. propane gas
pressure upstream of gas valve.
3
in"
w.c. minimum natural gas pressure or 10" w.c. propane gas
pressure downstream of gas valve- Can be adjusted by regula-
tor on gas valve.
4.
Verify gas manifold pressure (downstream of
gas
valve):
Before troubleshooting:
a. Natural gas:
Manifold pressure,high tire: 3.50"w.c.
1.
Have the following items:
a. Voltmeter that
can
check 120 V AC
and 24 VAC.
CGi-4
only- Manifold pressure, low tire: 090" w.c. while in low fire at
start·up (60seconds)
b. Propane gas:
Manifold pressure,high tire: IO.O"w.c.
b. Microammeter with a minimum
scale range of 0-25.
CGi-4
only- Manifold pressure, low tire: 3SO" w.c. while in low fire at
start·up (60 seconds)
c. Continuity checker.
d U-tube manometer.
c. If necessary, adjust gas pressure on the
gas
valve as shown below. After
adjustments, refer to page 35 to check the flame.
2. Check for 120 VAC (minimum 102 VAC
to maximmn 132 V AC) to boiler.
3.
Make sure them1ostat is calling for heat
and contacts (including appropriate zone
controls) are closed. Check for 24 VAC
between them1ostat wire nuts and ground.
pressure a4ustment
lloueywel
two-otage
gas
vtlve
11b
Troubleshooting - components
Air pressure switch
NOTICE
NOTICE
50
Make sure boiler water temperature is I 00 °F
or cooler before starting procedure to obtain
appropriate readings.
The boiler will not operate correctly unless
pressure S\vitch hoses are correctly located.
The red hose connects from the right side
(negative) hose barb to the flue collector. The
white hose connects from the left side (posi-
tive) hose barb of the switch to the connector
box (between flue collector and inducer) as
shown in Figure
36,
page
49.
Chec k pressure switch setting
1.
See Figure 36, page 49, and Table 9.
2. Remove
both
air pressure switch hoses from air pressure switch.
3. Install tees and tubing as shown in Figure
38.
page 49, to indined
manometer.
4. Turn off
gas
valve and set thermostat to call for heaL Inducer will
run but burners will not ignite.
5. Check for 24 VAC between both air pressure switch terminals.
Part Number 550-142-780/0712