Weil-McLain WM97+100 Manual page 124

WM97+ Series 2
Cleaning heat exchanger flue side, 155
Inspect refractory and replace burner gasket
1. See Figure 128, page 125 part D.
a. Inspect the refractory to make sure it is intact, with no
visible damage.
b. If the refractory must be replaced, use a wide-blade putty
knife to gently pry the refractory from the heat exchanger
cover plate. The refractory is attached with silicone ad-
hesive and should separate with a little pressure on the
putty knife.
DO NOT gouge or crack the refractory. The re-
fractory is made of ceramic fiber materials. Read
the ceramic fiber WARNING on page 100 before
handling or disposing of ceramic fiber materials.
c. When replacing the refractory, apply a ring of silicone
adhesive on the cover plate. Place the refractory onto
the cover plate. Before handling the assembly, allow the
adhesive to set enough that the refractory is firmly held
in place.
2. Remove the burner gasket (item 12) from the heat exchanger
cover plate.
3. Clean the gasket surface with a soft brush to remove any
gasket residue.
4. The burner gasket must be replaced with a new one when the
boiler is re-assembled after servicing.
Inspect and clean the heat exchanger
1. Access the heat exchanger interior by following the previous
instructions. Remove and inspect the heat exchanger cover
plate gasket. Replace if necessary.
2. See Figure 128, page 125 part E.
3. Use a strong light to visually inspect the interior of the heat
exchanger. Make sure the flueways (tubes) are clear and
unobstructed.
4. Use a vacuum cleaner to remove any accumulation on the
heating surfaces. This includes removing any pieces of refrac-
tory than may have dropped into the exchanger.
DO NOT use any solvent when cleaning the ex-
changer.
5. If the vacuum cleaner is unable to clean completely, wash the
heating surfaces with clean, warm water.
a. Place a bucket under the boiler condensate drain con-
nection.
b. Loosen and move the condensate bracket, then loosen the
condensate trap upper nut and slide the trap off of the
drain connection. (See Figure 74, page 65 for reference.)
c. Spray water into the heat exchanger and tubes to remove
sediment. Collect water in the bucket below.
6. Inspect the heat exchanger cover plate gasket. Replace if is
damaged in any way.
Reinstall components
1. See Figure 128, page 125 for reference.
2. First, re-install the heat exchanger cover plate/refractory/
blower/venturi/gas valve assembly on the heat exchanger.
a. Seat the heat exchanger cover plate gasket on the heat
exchanger sealing surface.
b. Secure the heat exchanger cover plate (item 6) to the
heat exchanger with the five 6-mm nuts using a 10-mm
wrench.
– 124 –
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GAS FIRED WATER BOILER
Figure 127
A
B
C
D
E
F
1
2
3
4
5
6
7
3. Reinstall the burner (item 11), burner gasket (item 12) and
4. Reinstall the igniter assembly (item 7).
5. Reconnect the flexible gas line to the gas valve using two
6. Reinstall the air inlet silencer (item 1) by pressing onto the
7. Reconnect the wire harnesses to the blower and gas valve.
8. Reinstall the condensate trap and bracket on the boiler
— Boiler Manual
Legend for Figure 128, page 125
Boiler interior
Burner assembly
Boiler interior, showing
heat exchanger cover plate
(item 6) and burner cover plate
seal (item 13), with burner
assembly removed
Exchanger cover plate, blower
and other components,
showing combustion chamber
refractory (item 16)
Heat exchanger interior
Boiler lower interior, showing
condensate dish (item 20)
Inlet air silencer
Blower assembly
Gas valve
Burner access cover
Venturi assembly
Heat exchanger cover plate
Igniter assembly
c. Tighten the nuts gradually, adjusting a little at a time.
Alternate and repeat until all are tightened evenly.
d. Do not over-tighten (torques no more than 45 inch-
pounds).
burner access cover seal (item 13) on the heat exchanger
cover plate (item 6).
a. Insert and tighten the burner cover plate screws and wash-
ers (item 10) using a Phillips screwdriver. The screws must
be secure, with torque no more than 20 inch-pounds.
a. The igniter gasket must be intact and in good condition.
Replace with a new gasket if necessary.
b. Insert the igniter into the cover plate opening, with the
gasket in position.
c. Reinstall the two (2) Socket head Allen bolts finger tight.
d. Use a torque wrench to tighten the igniter screws. DO
NOT exceed 25 inch-pounds torque.
e. Reconnect the igniter wire and the igniter ground wire.
wrenches.
venturi (item 5). Rotate the air silencer clip (item 8) and snap
it onto the gas line.
condensate drain connection. (See Figure 74, page 65 for
reference.)
Perform a complete start-up procedure when put-
ting the boiler back into service. See page 90 and all
instructions for start-up and verification. Include a
soap suds leak test on all interior and exterior gas
piping after starting the boiler.
(continued)
8
Air silencer clip
9 (5) Heat exchanger cover plate
retainer nuts,
10 Burner cover retainer screws,
M4 Phillips plus flat washers
11 Burner
12 Burner gasket
13 Burner access cover seal
14 Burner gasket sealing surface
15 Burner sealing surface (lower
surface of burner flange)
16 Combustion chamber
refractory
17 Heat exchanger tube sheet
18 Heat exchanger cover plate
gasket
19 Heat exchanger outer shell
20 Condensate dish
21 Condensate dish joint
22 Control housing, rotated
forward
Part number 550-142-204/0117