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Troubleshooting — air pressure switch, Gold cgs gas-fired water boiler – Weil-McLain GOLD CGS 550-110-260/02002 User Manual

Page 42

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Part number 550-110-260/0200

42

GOLD

CGs

Gas-Fired Water Boiler

Troubleshooting —

air pressure switch

11b

Make sure boiler water temperature
is 100 °F or cooler before starting
procedure to obtain appropriate
readings.

Check pressure switch setting

1. See

Figure 24

and

Table 6

.

2. Remove both air pressure switch hoses from air

pressure switch.

3. Install tees and tubing as shown in

Figure 24

to

inclined manometer.

4. Turn off gas valve and set thermostat to call for heat.

Inducer will run but burners will not ignite.

5. Check for 24 VAC between both air pressure switch

terminals and ground.

6. If manometer reading is above the setpoint of the

switch (see

Table 6

), but there is not 24 VAC

between both air pressure switch terminals and
ground — replace air pressure switch.

Figure 24

Manometer connections

Table 6

Pressure switch setpoint

(for elevations above 2,000 ft, contact your
local Weil-McLain sales office for details.)

Suction

Pressure

Inclined tube
manometer

White

White

White

Flue collector

Interior panel

Rear
panel

Side
panel

Red

Red

Red

26035

Boiler model number

Inches W.C.

CGs-3

1.79"

CGs-4

1.48"

CGs-5

1.22"

CGs-6

0.95"

The boiler will not operate correctly
unless pressure switch 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 (positive) hose
barb of the switch to the connector
box (between flue collector and
inducer) as shown in

Figure 24

.

Return to normal operation

When pressure reading is correct and air pressure
switch is operating properly — remove tees and
reinstall hoses to air pressure switch.

Troubleshooting air pressure reading

1. If manometer reading is lower than the setpoint

of the switch (see

Table 6

) — check for possible

causes:

blockage in hoses

obstruction in inducer housing outlet

loose inducer wheel on motor shaft

inducer motor not in proper rpm

inducer back plate not sealed properly

blockage in block assembly

blockage in flue pipe or termination

incorrect pressure switch