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P/N 42-9470 11/07 Copyright 2007 Mestek, Inc.
Cast iron condensing boiler
Cast iron condensing boiler
— Installation and operation manual
Accessing the burner
If the fi lter enclosure and blower inlet show signs of drywall dust,
construction debris or other deposits, you may need to inspect the
burner. Follow the procedure below. Accumulation of debris in the
burner can result in burner damage and potential for severe personal
injury, death or substantial property damage.
Perform this procedure only if evidence indicates the burner may be
fouled or damaged.
Turn the boiler on/off switch
OFF
.
Close the manual gas valve.
Remove the boiler jacket top following the procedure given on page 39.
Disconnect the gas supply piping at the ground joint union installed adjacent to
the boiler.
Carefully remove the upper insulation (item 4, Figure 35)that covers the upper
section cover. See Figure 35. Set the insulation aside for reuse.
Th e upper insulation must be replace aft er completing this work to
prevent overheating of the gas valve, blower and jacket top.
6. To access the bolts and nuts that secure the upper section cover:
Remove the sheet metal cover plate at the fl ame observation window (item 1,
Figure 35).
Remove the plastic plug from the jacket rear (item 2, Figure 35).
Remove the upper electrical panel cover plate (item 3, Figure 35).
Removing these items provides open-end wrench access to the ¼ inch bolts
and nuts.
7. Remove the seven ¼ inch bolts, nuts and washers that secure the upper section
cover (item 2, Figure 36). Note for reinstallation that there is a fl at washer on both
sides of the assembly and a lock washer on top.
8. Disconnect the three wire harnesses at the gas valve and blower (items 2 and 3,
Figure 36). In this illustration, the wires are not shown.
9. Lift the upper cover plate/blower/gas valve assembly off of the section assembly. (Th
e
upper section cover gasket is adhered to the bott om the cover with silicone RTV.)
10. Th e burner is now exposed.
11. Lift the burner up as in Figure 37 and inspect both sides. (Th e burner gasket is
adhered to the bott om the cover with silicone RTV .)
12. Look down into the section assembly to verify it is clean. If the heat exchanger is
blocked with sediment or shows damage, contact Mestek immediately for correc-
tive action.
13. If the burner is damaged, obtain a replacement burner from your distributor. In-
stall the new burner.
14. If the burner is fouled with debris, att empt to clean by using a shop vacuum. Be
careful not to damage the burner surface. If the burner cannot be cleaned, obtain a
replacement from your distributor.
15. Inspect the ceramic fi ber chamber (item 3, Figure 37) and fi ber gasket (item 2,
Figure 37). Make sure they are in good condition, or replace.
16. Replace the burner or install a new one.
17. Replace all components in the reverse order from above.
Use extreme care when replacing the upper section cover. Th
e seal must
be secure to avoid potential of carbon monoxide leakage or heat damage
caused by fl ue gas spillage. Inspect all components to ensure they are in
good condition and correctly installed. Soap suds leak test the gas line,
particularly the ground joint union, to ensure the gas line is intact aft er
servicing. Follow servicing by a complete start-up/test procedure of the
boiler.
1.
2.
3.
4.
5.
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•
•
•
Figure 35
Preparing to remove upper section cover
Figure 37
Burner and chamber
Figure 36
Upper cover bolt locations
Maintenance
(continued)
14