Remove And Inspect Ignition Electrode Assembly And Wiring; Remove And Inspect Flame Sense Rod And Wiring; Remove, Inspect And Clean The Burner; Inspect Combustion Chamber And Refractory - Weil-McLain Evergreen EVG 220 Manual

®
gas
Annual startup
3. Remove the air baffle (item 2) and screws (item 4) from the
jacket top as shown.
Remove and inspect ignition
electrode assembly and wiring
1. See Figure 93, page 98 (EVG 220 shown) for component
references below.
2. Disconnect the ground wire and ignition cable connected to
the ignition electrode assembly (item 7).
3. Use a 3 mm Allen wrench to remove the two (2) screws se-
curing the ignition electrode assembly to the heat exchanger
cover plate (item 6).
4. Carefully remove the ignition electrode assembly from the
heat exchanger cover plate.
5. Discard the ignition electrode assembly gasket.
6. Inspect the ignition electrodes and ceramic insulators.
a. Remove any white oxides accumulated on the ignition
electrodes using steel wool.
b. Clean the gasket surfaces on the ignition electrode as-
sembly flange and on the mating surface of the heat
exchanger cover plate.
c. If the ignition electrode ceramic is cracked or damaged, or
if the electrodes cannot be cleaned satisfactorily, replace
the ignition electrode assembly with a new one.
7. Slide the new gasket onto the ignition electrode assembly.
8. Set the ignition electrode assembly with new gasket aside for
later re-insertion.
9. Check ignition cable electrical resistance.
a. A good cable will have resistance between 950 and 1050
ohms.
b. Replace cable if not acceptable.
10. Verify all wiring is in good condition and securely attached.
11. Inspect boiler ground wire from heat exchanger access cover
to ground terminal screw in control tray.
a. Check resistance. It should be 0 ohms.
b. Check ground continuity of wiring using continuity
meter.
c. Replace ground wires if results are not satisfactory.
Remove and inspect flame sense rod
and wiring
1. See Figure 93, page 98 (EVG 220 shown) for component
references below.
2. Disconnect the flame sense wire connected to the flame sense
rod (item 8).
3. Use a 3 mm Allen wrench to remove the two screws securing
the flame sense rod assembly to the heat exchanger cover plate.
Carefully remove the flame sense rod.
4. Discard the flame sense rod gasket.
5. Inspect the flame sense rod and ceramic.
a. Remove any white oxides accumulated on the flame
sense rod.
b. Clean the gasket surfaces on the flame sense assembly
flange and on the mating surface of the heat exchanger
cover plate.
Part number 550-100-131/0120
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fired water boiler
(continued)
— 220/299/300/399 Boiler Manual
c. If the flame sense rod is bent or cannot be cleaned satis-
factorily or if the ceramic is cracked or damaged, replace
the flame sense rod assembly with a new one.
6. Slide the new gasket onto the flame sense rod assembly.
7. Inspect flame sense wire from flame sense connector to the
connector at the control module in boiler control tray.
a. Check resistance. It should be 0 ohms.
b. Replace Wire Harness– Low Voltage if results are not
satisfactory.

Remove, inspect and clean the burner

1. See Figure 93, page 98 (EVG 220 shown).
2. Use a Phillips stubby screwdriver to remove the four (4) M4
screws (item 10) that secure the burner access cover (item 4)
to the heat exchanger cover plate (item 6).
3. Remove the burner access cover (item 4) and the burner
(item 11).
Use caution when removing the burner to pull it
directly up and out. DO NOT angle the burner as
you remove it. Angling the burner could cause it to
strike the refractory, damaging the refractory and
causing fragments to fall into the heat exchanger.
Should this happen, a heat exchanger refractory
replacement kit must be installed and the heat ex-
changer must be thoroughly cleaned following the
procedures given in this manual and the refractory
replacement instructions.
4. Remove and discard the burner gasket (item 12). This gasket
is graphite and may pull apart or stick to the burner on re-
moval. Use a soft brush if necessary to remove residue. DO
NOT allow debris to drop into the heat exchanger. A new
gasket must be installed later when the burner is re-inserted.
5. Inspect the burner access cover seal (item 13). Discard and
use a new seal during re-assembly if the seal is damaged in
any way.
6. Inspect the interior of the burner. Brush and vacuum the
interior if needed to remove lint or sediment. Alternative
cleaning methods:
a. Blow air or nitrogen from the inside out.
b. Clean with a water spray from inside the burner.
7. Inspect the burner exterior. It must be in good condition,
with no visible damage.
8. Clean the under side of the burner flange (see item 15) with
a soft brush to remove any gasket fragments remaining.
9. Set the burner aside for re-insertion later.
Inspect combustion chamber and
refractory
1. Look into the burner opening in the heat exchanger cover
plate.
2. Use a trouble light and inspection mirror to inspect the heat
exchanger interior.
a. Make sure that there is no debris inside the heat exchanger.
b. Use the inspection mirror to check the condition of the
burner refractory that is adhered to the bottom of the
heat exchanger cover plate. It must be in good condition
with no indication of damage or sagging.
c. Make sure there are no signs of overheating or of flue
gas leakage.
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