Watts AERCO 58025-05 Owner's manual

TID-0066_0B
AERCO International, Inc. •100 Oritani Dr. •Blauvelt, New York 10913 •Phone: [phone]
TECHNICAL INSTRUCTIONS
Latest Update: 10/16/2014
24-Month Maintenance
Kit P/N 58025-05
For BMK1.5LN Boilers
Description of Document:
This TID provides the procedures to perform
recommended 24-Month maintenance on the
following Benchmark Low NOx Boiler Models:
•Benchmark 1.5LN
•Benchmark 1.5LN Dual-Fuel
BMK 1.5LN Blower/Burner Assembly

VD2: 10/14/14 Page 2 of 24
BMK1.5 LN Boiler 24-Month Maintenance Kit #58025-05 Instructions
Technical Instruction Document
TID-0066_0B
AERCO International, Inc. •100 Oritani Dr. •Blauvelt, New York 10913 •Phone: [phone]
TABLE OF CONTENTS
1. INTRODUCTION................................................................................3
2. CONTENTS OF 24-MONTH MAINTENANCE KIT ..............................3
3. TOOLS, TEST EQUIPMENT AND MATERIALS REQUIRED...............3
3.1 Tools ................................................................................................................3
3.2 Test Equipment...............................................................................................4
3.3 Materials ..........................................................................................................4
4. PRELIMINARY INSPECTION PROCEDURES ....................................4
5. WATERSIDE INSPECTION OF THE HEAT EXCHANGER..................5
6. FIRESIDE INSPECTIONS & COMPONENT REPLACEMENT .............7
6.1 Burner Maintenance ......................................................................................7
6.1.1 Burner Disassembly and Inspection........................................................................ 7
6.1.2 Preliminary Burner Reassembly........................................................................... 12
6.1.3 Burner Component Replacement.......................................................................... 13
6.1.4 Final Burner Reassembly...................................................................................... 15
6.2 Exhaust Manifold Maintenance....................................................................15
6.2.1 Exhaust Manifold Disassembly and Inspection.................................................... 15
6.2.2 Exhaust Manifold Reassembly ............................................................................. 16
6.2.3 Condensate Trap Component Replacement.......................................................... 17
6.3 Replacing the LWCO Probe/Capacitor Assembly......................................20
6.3.1 Low Water Cutoff (LWCO) Capacitor Integrity Test .......................................... 20
7. FINAL REASSEMBLY AND TESTING..............................................23
7.1 Set-Up and Reassembly After Maintenance...............................................23
7.2 Final Testing After Maintenance..................................................................23
Disclaimer
The information contained in this manual is subject to change without notice from
AERCO International, Inc. AERCO makes no warranty of any kind with respect to this
material, including, but not limited to, implied warranties of merchantability and fitness for
a particular application. AERCO International is not liable for errors appearing in this
manual. Nor for incidental or consequential damages occurring in connection with the
furnishing, performance, or use of this material.
Technical Support:
(Mon–Fri, 8am-5pm EST)
1-800-526-0288
www.aerco.com

VD2: 10/14/14 Page 3 of 24
BMK1.5 LN Boiler 24-Month Maintenance Kit #58025-05 Instructions
Technical Instruction Document
TID-0066_0B
AERCO International, Inc. •100 Oritani Dr. •Blauvelt, New York 10913 •Phone: [phone]
1. INTRODUCTION
This Technical Instruction Document (TID) provides the procedures to perform waterside and
fireside inspections of the heat exchanger contained in Benchmark 1.5LN and 1.5LN Dual-Fuel
boilers equipped with an Igniter-Injector.
This kit provides the parts required to perform the waterside and fireside inspections on the
Benchmark 1.5LN and Dual-Fuel Boilers.
2. CONTENTS OF 24-MONTH MAINTENANCE KIT
The items included in the 24-Month Maintenance Kit are listed in Table 1.
Table 1:Benchmark 1.5LN 24-Month Inspection Kit, Part No. 58025-05
ITEM
QTY
PART NO.
DESCRIPTION
1 1 58023
IGNITER/INJECTOR REPLACEMENT KIT:
1 x IGNITER-INJECTOR – P/N 66026
1 x NUT, COMPRESSION – P/N 56047
3 x WASHERS, CLOCKING (INDEXING) – P/N 53033
1 x LUBRICANT, ANTI-SEIZE - 89012
2 1 24356-1
FLAME DETECTOR REPLACEMENT KIT:
1 x FLAME DETECTOR – P/N 66034
1 x FLAME DETECTOR GASKET – P/N 81048
3 1 84020 EXHAUST MANIFOLD SEAL
4 2 81063 BURNER GASKETS
5 1 81064 BLOWER GASKET
6 1 84017 CONDENSATE TRAP O-RING
7 1 81092 CONDENSATE TRAP ORIFICE GASKET (.25" I.D.)
8 1 88003 AIR/FUEL VALVE TO GAS TRAIN O-RING
9 1 69126 LWCO / CAPACITOR ASSEMBLY KIT
10 1 81129 PLUG GASKET
3. TOOLS, TEST EQUIPMENT AND MATERIALS REQUIRED
The items required to perform the inspections, replacements and tests specified in these
instructions are listed in paragraph 3.1, 3.2 and 3.3 which follow.
3.1 Tools
Common hand tools, plus the items listed below are required:
•Small Wire Brush
•Flashlight
•Wrench set (box or open-ended)

VD2: 10/14/14 Page 4 of 24
BMK1.5 LN Boiler 24-Month Maintenance Kit #58025-05 Instructions
Technical Instruction Document
TID-0066_0B
AERCO International, Inc. •100 Oritani Dr. •Blauvelt, New York 10913 •Phone: [phone]
3.2 Test Equipment
No test equipment is required to perform the 24-month inspections and maintenance included in
these instructions. However, following completion of these inspections, the Benchmark Boiler
should be tested using the combustion calibration procedures provided in O & M Manual
GF-120, GF-120M (Massachusetts only), or GF-121 (Dual-Fuel).
3.3 Materials
Expendable materials required to perform the procedures described in this bulletin are not
included in the 24 -Month Inspection Kits. These materials may include such items as:
•Pipe joint compound
•Teflon tape
•Cleaning solvents and materials
•Loctite 246
4. PRELIMINARY INSPECTION PROCEDURES
The detailed procedures required to perform the waterside and fireside inspections included in
these instructions are provided in sections 5 and 6. However, prior to performing the procedures
in section 5 and 6, perform the preliminary safety, set-up and disassembly procedures
described in the following steps:
WARNING!
FAILURE TO FOLLOW SAFETY INSTRUCTIONS REGARDING
PREPARATION OF THE UNIT, AS DESCRIBED BELOW, MAY
RESULT IN INJURY, DEATH, OR DAMAGE TO EQUIPMENT.
Preliminary Inspection Instructions
1. At the front panel of the unit, set the ON/OFF switch on the C-More Control Panel to the
OFF position.
2. Disconnect electrical power to the unit by turning off the external circuit breaker.
3. Turn off the external gas supply shutoff valve.
4. Close the water supply and return valves to the unit.
5. Refer to Figure 1 and remove the top and side panels of the unit.
6. With the top and side panels removed, the Benchmark 3.0LN Burner, heat exchanger and
Exhaust Manifold can be accessed to prepare the boiler for the required waterside and
fireside inspections described in sections 5 and 6.

VD2: 10/14/14 Page 5 of 24
BMK1.5 LN Boiler 24-Month Maintenance Kit #58025-05 Instructions
Technical Instruction Document
TID-0066_0B
AERCO International, Inc. •100 Oritani Dr. •Blauvelt, New York 10913 •Phone: [phone]
Figure 1: Benchmark 1.5 Low NOx (LN) Boiler
5. WATERSIDE INSPECTION OF THE HEAT EXCHANGER
Benchmark 1.5LN Models contain a single heat exchanger, as shown in Figure 2. Perform the
waterside inspection as follows:
Burner Preliminary Disassembly and Inspection Instructions
1. Ensure that the preliminary safety, set-up, and disassembly procedures in section 4 have
been performed to provide access to the heat exchanger of the unit.
2. Allow the unit to cool prior to proceeding.
3. At the rear of the unit (Figure 3), slowly open the drain valve and drain the boiler water
from the heat exchanger.
4. Open the P&T relief valve (Figure 2) to allow air to enter the heat exchanger during
draining.
5. After the heat exchanger has been drained, remove the 2-1/2 inch access port plug on the
right side of the heat exchanger, as shown in Figure 2.
6. If waterside inspection is required by your local inspector, follow the inspector's
instructions. Upon satisfactory completion of the inspection, proceed to step 7.
7. Apply pipe compound to the threads of the access port plugs and replace them using a
pipe wrench.
8. Close the drain valve at the rear of the boiler.
9. Close the P&T relief valve.
10. Open the water supply and return valves to the unit and refill the heat exchanger. This
completes the waterside inspection for the unit.
2 SIDE PANELS
(EACH SIDE)
TOP PANEL

VD2: 10/14/14 Page 6 of 24
BMK1.5 LN Boiler 24-Month Maintenance Kit #58025-05 Instructions
Technical Instruction Document
TID-0066_0B
AERCO International, Inc. •100 Oritani Dr. •Blauvelt, New York 10913 •Phone: [phone]
Figure 2: Benchmark 1.5LN - (Side View)
Figure 3:Benchmark 1.5LN - (Rear View)

VD2: 10/14/14 Page 7 of 24
BMK1.5 LN Boiler 24-Month Maintenance Kit #58025-05 Instructions
Technical Instruction Document
TID-0066_0B
AERCO International, Inc. •100 Oritani Dr. •Blauvelt, New York 10913 •Phone: [phone]
6. FIRESIDE INSPECTIONS & COMPONENT REPLACEMENT
The heat exchanger fireside inspection includes removal of the Burner and recommended
replacement of Burner components and inspection of the Exhaust Manifold assembly and
replacement of Condensate Trap components. The 24-Month Maintenance Kit includes the
recommended replacement parts for annual maintenance which should also be performed at
this time. Therefore, the procedures in this section are organized as follows:
Burner Maintenance – section 6.1:
•Burner Disassembly and Inspection
•Preliminary Burner Reassembly
•Burner Component Replacement
•Final Burner Reassembly
Exhaust Manifold & Condensate Maintenance – section 6.2:
•Exhaust Manifold Disassembly and Inspection
•Exhaust Manifold Reassembly
•Condensate Trap Component Replacement
LWCO (Low Water Cut-Off) Capacitor Replacement and Testing – section 6.3:
•LWCO replacement
•LWCO testing
6.1 Burner Maintenance
Perform the fireside inspections of the low NOx Burner and replacement of Burner component
parts using the procedures in the following paragraphs, 6.1.1 and 6.1.2.
6.1.1 Burner Disassembly and Inspection
The Burner Assembly is located at the top of the heat exchanger as shown in Figure 4. The
complete Burner Assembly for Benchmark 1.5LN also includes the Blower and Air/Fuel Valve
assemblies for the unit. Figure 4 shows the Burner Assembly mounting details and Figure 5
shows an exploded diagram of the complete Burner Assembly removed from the unit.

VD2: 10/14/14 Page 8 of 24
BMK1.5 LN Boiler 24-Month Maintenance Kit #58025-05 Instructions
Technical Instruction Document
TID-0066_0B
AERCO International, Inc. •100 Oritani Dr. •Blauvelt, New York 10913 •Phone: [phone]
Figure 4: Benchmark 1.5LN - Top View
FLAME
DETECTOR
(P/N 66034)
IGNITER-
INJECTOR
(P/N 66026)

VD2: 10/14/14 Page 9 of 24
BMK1.5 LN Boiler 24-Month Maintenance Kit #58025-05 Instructions
Technical Instruction Document
TID-0066_0B
AERCO International, Inc. •100 Oritani Dr. •Blauvelt, New York 10913 •Phone: [phone]
Figure 5: BMK1.5LN Burner Assembly - Exploded View
Remove and inspect the Burner Assembly as follows:
Burner Preliminary Disassembly and Inspection Instructions
1. Ensure that the preliminary set-up and disassembly procedures in section 4 have been
completed.
WARNING
THE BURNER ASSEMBLY MAY BE EXTREMELY HOT. TO
AVOID BURNS, ALLOW IT TO COOL SUFFICIENTLY BEFORE
ATTEMPTING TO REMOVE IT FOR INSPECTION.
2. Disconnect the lead wire from the Flame Detector shown in Figure 6. Unscrew the two
screws and remove the Flame Detector and gasket.
3. Disconnect the igniter cable from the igniter (Figure 6).
BURNER GASKET (P/N 81063)
BLOWER GASKET
(P/N 81064)
IGNITER-INJECTOR
(P/N 66026)
FLAME DETECTOR GASKET (P/N 81048)
FLAME DETECTOR (P/N 66034)
OBSERVATION PORT
GROUNDING SCREW
BURNER
BURNER FLANGE
BURNER PLATE
HEX HEAD SCREWS (4)
A/F VALVE TO GAS TRAIN
O-RING (P/N 88003)
AIR/FUEL
VALVE
BLOCKED INLET SWITCH
BLOWER PROOF SWITCH
BLOWER
STAGED IGNITION SOLENOID
BURNER GASKET (P/N 81063)

VD2: 10/14/14 Page 10 of 24
BMK1.5 LN Boiler 24-Month Maintenance Kit #58025-05 Instructions
Technical Instruction Document
TID-0066_0B
AERCO International, Inc. •100 Oritani Dr. •Blauvelt, New York 10913 •Phone: [phone]
4. Refer to the partial exploded view in Figure 6. Using a 7/16” open-end wrench, disconnect
the compression nut securing the Gas Injector Tube of the Igniter-Injector to the elbow of
the Staged Ignition Assembly. Remove the compression nut from the elbow and discard,
as it will be replaced with a new one from the kit at reassembly. Disconnect the Staged
Ignition Assembly from the Igniter-Injector.
5. Next, loosen and remove the Igniter-Injector from the Burner Plate using a 1" open-end
wrench.
6. Remove the two screws securing the Plug Gasket (P/N 81129), remove the existing Plug
Gasket and replace it with one from the kit, and then secure it with the two screws.
7. Disconnect the unit wiring harness connectors from the Air/Fuel Valve and Blower motor
(Figure 5).
8. Disconnect the Fast-On wire leads connected to the Blower Proof Switch and Blocked Inlet
Switch (Figure 5).
Figure 6: Partial Exploded View Showing Flame Detector, Igniter-Injector, and
Staged Ignition Assembly on Burner Plate
9. Disconnect the Gas-Train from the Air/Fuel Valve flange by removing the four (4) 1/2" bolts
and nuts (Figure 4). Remove the Air/Fuel Valve to Gas Train O-ring (P/N 88003), as it will
be replaced at reassembly.
10. Disconnect the inlet air flex hose from the Air/Fuel Valve (Figures 2 & 4) by loosening the
hose clamp.
COMPRESSION NUT
(P/N 56047)
IGNITER-INJECTOR
(P/N 66026)
IGNITER-INJECTOR
CABLE ATTACHED HERE
INDEXING WASHERS
(QTY=3) AS REQ’D
(P/N 53033)
BURNER PLATE
FLAME DETECTOR
GASKET (P/N 81048)
FLAME DETECTOR
(P/N 66034)
FLAME DETECTOR
LEAD WIRE
ATTACHED HERE
STAGED IGNITION
SOLENOID
INJECTOR TUBE
PLUG GASKET
(P/N 81129)