Weil-McLain Evergreen EVG 70 Manual page 122

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Cleaning heat exchanger fl ue side, 110
Inspect and clean the burner
1. See Figure 106, page 121 part D.
a. Slide the refractory (item 11) over the burner and off.
Set the refractory aside where it will be kept clean and
protected from damage. If the refractory is damaged, it
must be discarded and replaced with a new one.
b. Remove the four (4) #20 Torx screws (item 13) securing
the burner (item 9) to the cover plate. Set aside.
c. Remove the burner and its gasket (item 12).
d. Inspect the interior of the burner. Brush and vacuum the
interior if needed to remove lint or sediment. Alternative
cleaning methods: • blow air from the inside out; • clean
with a water spray from inside the burner; • swirl the
burner thoroughly in a bucket of mild liquid laundry
detergent water, then rinse thoroughly.
e. Inspect the burner exterior. It must be in good condition,
with no visible damage.
f. Obtain a new burner gasket before re-installing the
burner.
Inspect and clean the heat exchanger
1. Access the heat exchanger interior by following the previous
instructions.
2. See Figure 106, page 121 part E.
3. Before using water to clean the heat exchanger, remove the
control module (item 14). Label wires if they are not labeled.
Set aside. Remove all connectors and wire harnesses from the
control module and then remove the two (2) screws securing
it to the bracket.
4. Use a strong light to visually inspect the interior of the heat
exchanger. Make sure the fl ueways (tubes) are clear and
unobstructed.
5. Use a vacuum cleaner to remove any accumulation on
the heating surfaces. This includes removing any pieces of
refractory that 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. Loosen and move the condensate bracket, then loosen the
condensate trap upper nut and slide the trap off of the
drain connection. (See Figure 56, page 52 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 refractory. Replace if
insulation is damaged.
Reinstall components
1. See Figure 106, page 121 for reference.
2. Reinstall the control module (item 14) to the control bracket
and reconnect all connectors and wire harnesses.
3. Reinstall the burner (item 9) and burner gasket (item 12) on
the cover plate (item 6). Tighten the burner screws (item 13)
using a torque wrench. The screws must be secure, but the
torque must not exceed 20 inch-pounds.
122
as-fired water boiler — Boiler Manual
70/110/155
4. Apply a ring of silicone adhesive on the cover plate (to secure
the refractory).
5. Slide the refractory (item 11) over the burner. Align the
refractory and press in place.
6. handling the assembly, allow the adhesive to set
Before
enough that the refractory is fi rmly held in place.
7. 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) Socket head Allen bolts fi nger tight.
d. Use a torque wrench to tighten the igniter screws. DO
NOT exceed 20 inch-pounds torque.
8. Reinstall the cover plate assembly (items 5 and 6) and secure
the cover plate with 10mm hex nuts (item 8).
You must gradually tighten the cover plate nuts
using a torque wrench. The fi nal torque MUST
NOT exceed 45 inch-pounds. Alternate tightening
until all nuts reach 45 inch-pounds.
9. Reconnect the ignition cable and the igniter ground wire.
10. Reinstall the blower, venturi, gas valve assembly.
a. Inspect the blower to cover plate gasket, replace if gasket
is damaged or has taken a set.
b. Slide the blower assembly up to the cover plate, passing the
two (2) blower studs up through the cover plate holes. Use
the two locking nuts to secure the assembly, torx locking
nuts to 20 inch-pounds.
c. Reinstall the fl exible gas line by using two wrenches to
tighten the union fi tting between the gas line and the gas
valve fl are adapter.
11. Reinstall the air silencer (item 1).
12. Reinstall the two (2) electrical connectors from the blower
and one connector from the gas valve.
13. Reinstall the condensate trap and bracket on the
boiler condensate drain connection, if removed. (See
Figure 56, page 52 for reference.)
Perform a complete start-up procedure when
putting the boiler back into service. See page 91
and all instructions for start-up and verifi cation.
Include a soap suds leak test on all interior and
exterior gas piping after starting the boiler.
(continued)
Part number 550-100-191/0917