Install Instructions

Cleaning heat exchanger fl ue side, 110
Cleaning the EVG 110 hea t exch anger
FLUE SIDE or ac cessing the burner, if
required
The boiler contains ceramic fi ber materials. Use care
when handling these materials per instructions on
page 101 of this manual. Failure to comply could
result in severe personal injury.
Tools required
• Long-handled Torx driver, #20
• T25 Torx Bit
• 3mm Allen wrench
• Phillips head screwdriver, #2
• Nut driver,
5/16"
• Torque wrench
• Putty knife
• Wrench or socket, 10mm
• (2) Large Crescent wrenches
Before proceeding:
1. Shut down the boiler:
a. Follow “To Turn Off Gas to Appliance” instructions on
boiler and Operating instructions.
b. Close the boiler manual gas valve.
2. Allow time for the boiler to cool to room temperature if it
has been fi ring.
3. Remove jacket door by removing top retaining screw and
undoing the two (2) latches on each side. Rotate and lift the
jacket door away from the boiler to remove.
Remove components to allow access
1. See Figure 106, page 121 part A to locate components
referenced in the following.
2. Disconnect the communication board terminal strip and
4-pin connector from communication board and lift up and
remove display bracket.
3. Remove the air baffl e (item 28, page 3) by removing the two
(2) hex head screws in front of the air intake adapter (item
16 page 3). Set aside.
4. See Figure 106, page 121 part B.
a. Release the air silencer bracket free from gas line.
b. Remove the air silencer from the venturi by sliding
it away from the blower/venturi assembly. Set the air
silencer aside.
c. Remove the two (2) electrical connectors from the blower
and one connector from the gas valve.
d. By using two wrenches, loosen the union fi tting between
the fl exible gas line and the gas valve fl are adapter. Gently
set the fl ex line aside, where it is out of the way and free
from damage.
e. Remove the blower/venturi/gas valve assembly by
removing the two (2) nuts connecting the blower to the
cover plate.
f. Remove the four (4) 10mm hex nuts (item 8) that secure
the heat exchanger cover plate (item 6).
g. Disconnect the ground wire and ignition cable from the
igniter (item 7).
Label all wires prior to disconnection when
servicing controls. Wiring errors can cause
improper and dangerous operation.
h. Lift the cover plate/burner assembly vertically until the
refractory (part C, item 11) clears the heat exchanger.
i. Tilt the cover plate/burner assembly slightly forward.
Then pull the assembly forward and out of the jacket.
j. Remove the igniter by removing the two (2) Socket head
Allen igniter bolts. Set the igniter, its gasket and screws
aside. Be careful when handling the igniter not to damage
the igniter ceramic.
k. Inspect the igniter ceramic and electrodes. Clean the
electrodes carefully with steel wool. If the igniter ceramic
is cracked or damaged, replace the igniter with a new one.
Handle the cover plate/burner assembly carefully to
avoid damage to the igniter or refractory. Place the
assembly on a clean, fl at surface with the assembly
upside down, as shown in Figure 106, page 121
part C and part D.
4. See Figure 106, page 121 part C.
a. Use a wide-blade putty knife (item 10) to gently pry
the refractory from the heat exchanger cover plate. The
refractory is attached with silicone adhesive and should
separate with a little pressure on the putty knife.
DO NOT gouge or crack the refractory. The
refractory is made of ceramic fi ber materials. Read
the ceramic fi ber WARNING on page 101 before
handling or disposing of ceramic fi ber materials.
Figure 103 Legend for Figure 106 , page 107
A Boiler interior
B Boiler interior, with
components disconnected
to allow removal of
combustion chamber cover
plate
C Combustion chamber cover
plate and components
removed from boiler
D Disassembling to access the
burner
E Heat exchanger interior
1 Inlet air silencer
2 Blower assembly
3 Gas valve
4 Venturi gas line clip
5 Venturi assembly
6 Heat exchanger cover plate
7 Ignitor assembly
8 Combustion chamber cover
plate retainer nuts (4)
9 Burner
10 Putty knife
11 Refractory
12 Burner gasket
13 (3) Burner retainer screws
14 Control module
Part number 550-100-191/0917
120
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gas-fired water boiler — 70/110/155 Boiler Manual