Weil-McLain ECO 70 Manual page 104

TM -
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AS FIRED WATER BOILER
Cleaning heat exchanger flue side, 155
DO NOT gouge or crack the refractory. The re-
fractory is made of ceramic fiber materials. Read
the ceramic fiber WARNING on page 84 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.
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 107, page 105 part E.
3. Before using water to clean the heat exchanger, remove the
control module (item 20). Label wires if they are not labeled.
Set aside. Remove all connectors and wire harnesses from the
control module and then remove the two screws securing it to
the bracket.
4. Use a strong light to visually inspect the interior of the heat
exchanger. Make sure the flue ways (tubes) are clear and un-
obstructed.
5. Use a vacuum cleaner to remove any accumulation on the heating
surfaces. This includes removing any pieces of refractory than
may have dropped into the exchanger.
DO NOT use any solvent when cleaning the
exchanger.
6.
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
connection.
b. Then loosen the condensate trap upper nut and slide the
trap off of the drain connection. (See Figure 59, page 54
for reference.)
c. Spray fresh water into the heat exchanger and tubes to
remove sediment. Collect water in the bucket below.
7. Inspect the heat exchanger cover plate gasket (item 18). Replace
if is damaged in any way.
1. See Figure 107, page 105 for reference.
2. Reinstall the control module (item 20) to the control bracket
and reconnect all connectors and wire harnesses.
3. Reinstall the burner (item 11), burner gasket (item 12) and
burner access cover seal (item 13) on the heat exchanger cover
plate (item 6).
a. Insert and tighten the burner cover plate screws and
washers (item 10) using a Phillips screwdriver. The screws
must be secure, with torque no more than 20 inch-pounds.
4. Reinstall the heat exchanger cover plate assembly on the heat
exchanger.
104
— Boiler Manual
Legend for Figure 107
A Boiler interior
B 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)
E Heat exchanger interior
1 Inlet air silencer
2 Blower assembly
3 Gas valve
4 Burner access cover
5 Venturi assembly
6 Heat exchanger cover plate
7 Igniter assembly
a. Seat the heat exchanger cover plate gasket on the heat
exchanger sealing surface.
b. Tilt heat exchanger cover plate front lip downward until back
lip clears cabinet and burner can slide inside combustion
chamber. Slide cover plate back and rotate until seated flat
on the heat exchanger sealing surface. Avoid gouging the
refractory on the heat exchanger studs.
c. Secure the heat exchanger cover plate (item 6) to the heat
exchanger with the five (5) M6 nuts using a 10-mm wrench.
You must gradually tighten the cover plate nuts using a
torque wrench. The final torque MUST NOT exceed 45
inch-pounds. Alternate tightening until all nuts reach 45
inch-pounds.
5. Reinstall the blower/gas valve/venturi assembly (items 2, 3, and 5).
a. Place blower flange on to studs protruding from cover plate.
b. Reinstall the two
c. Do not over tighten (torque no more than 20 inch-pounds).
6. Reinstall the igniter assembly (item 7).
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) Phillips head screws finger tight.
d. Use a torque wrench to tighten the igniter screws. DO
NOT exceed 25 inch-pounds torque.
e. Reconnect the ignition cable and the igniter ground wire.
7. Reconnect the flexible gas line to the gas valve using two wrenches.
8. Reinstall the air inlet silencer (item 1) by pressing up onto the venturi
(item 5). Rotate the air silencer clip (item 8) and snap it onto the gas line.
9. Reconnect the wire harnesses to the blower and gas valve.
10. Reinstall the condensate trap on the boiler condensate drain
connection. (See Figure 59, page 54 for reference.)
Perform a complete start-up procedure when put-
ting the boiler back into service. See page 75 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 Control module
5/16 " locknuts using a socket with extension,
Part number 550-142-122/0513