technical instructions -...

Benchmark 2500-3000 Boiler 24 Month Maintenance Kit 58025-10 TID-0102_0D

09/15/2014 AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, New York 10913 • Phone: 800-526-0288 of 16

Maintenance Kit # 58025-10 Latest Update: 09/15/2014

ITEM 7 Condensate Trap O-Ring P/N 84017 (1 each)

ITEM 11 LWCO

Capacitor Kit P/N 69126 (1 each)

ITEM 10 Exhaust

Manifold Seal P/N 84040 (1 each)

ITEM 1 Igniter-Injector

P/N 58023 (1 each)

ITEM 4 Flame

Detector P/N 66034 (1 each)

ITEM 3 Air Filter

P/N 88014 (1 each)

ITEM 5 Flame Detector

Gasket P/N 81048 (1 each)

ITEM 9 Blower Gasket

P/N 81157 (1 each)

ITEM 2 Burner

Release Gasket P/N

81173 (1 each)

ITEM 8 Burner Gasket

P/N 81180 (1 each)

ITEM 6 Condensate Trap

Orifice Gasket P/N 81092 (1 each)

ITEM 12 Lower Release

Gasket P/N 81185

(1 each)

24-Month Maintenance Kit For Benchmark 2500-3000 Boilers

TECHNICAL INSTRUCTIONS



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 these materials.

1. INTRODUCTION This Technical Instruction Document (TID) provides instructions for performing recommended 24 month maintenance on Benchmark 2500 and Benchmark 3000 Boilers.

2. LIST OF TOOLS The following tools are required to perform the instructions in this bulletin.

• Flat-head screwdriver or 5/16” nut driver • Phillips head screwdriver #2 • 6mm Allen wrench • Torque wrench • The following wrenches (open-end, box or socket) are used:

o 3/8” o 7/16“ o 1/2“

o 9/16” o 1”

3. MAINTENANCE KIT CONTENTS

Table 1: Contents of Benchmark 2500-3000 24 Month Maintenance Kit 58025-10

Item Part No. Quantity Description 1 58023 1 IGNITER-INJECTOR 2 81173 1 BURNER RELEASE GASKET 3 88014 1 AIR FILTER 4 66034 1 FLAME DETECTOR 5 81048 1 FLAME DETECTOR GASKET 6 81092 1 CONDENSATE TRAP ORIFICE GASKET 7 84017 1 CONDENSATE TRAP O-RING 8 81180 1 BURNER GASKET 9 81157 1 BLOWER GASKET

10 84040 1 EXHAUST MANIFOLD SEAL 11 69126 1 LWCO / CAPACITOR ASSEMBLY KIT 12 81185 1 LOWER RELEASE GASKET



4. INSTALLATION INSTRUCTIONS WARNING!

• Remove electrical power before working on the unit. Adhere to all local codes regarding lock-out, tag-out procedures.

• The igniter-injector and flame detector may be very hot, use care to avoid burns. It is advised to allow the unit to cool to room temperature before starting these procedures.

4.1 Replacing the Blower and Burner Gaskets The instructions in this section replace the blower gasket (P/N 81157) and burner gasket (P/N 81180). In addition, these instructions also remove the igniter-injector (P/N 58023), flame detector (P/N 66034) and flame detector gasket (P/N 81048) from the boiler; they are replaced in sections 4.2 and 4.3.

Replacing the Blower and Burner Gaskets 1. Set the ON/OFF switch on the control panel, to the OFF position and then disconnect AC

power from the unit by turning off power at the breaker.

2. Shut off the gas supply valve to the unit.

3. Remove the panels from the top and sides of the unit, exposing the intake manifold and blower.

4. Disconnect the electrical cable from the igniter.

Figure 1: Gasket, Igniter-Injector & Flame Detector Locations

5. Use a 7/16” wrench to disconnect the compression nut securing the igniter-injector’s gas injector tube to the elbow of the staged ignition assembly and then disconnect the staged ignition solenoid from the igniter-injector. Discard the old compression nut.

O2 Sensor

Burner Plate

Staged Ignition Solenoid

Blower Plenum

Igniter-Injector

Flame Detector & Gasket

Blower Gasket

Burner Gasket



Replacing the Blower and Burner Gaskets - Continued

Figure 2: Igniter-Injector Disassembly

6. Use a 1" wrench to remove the igniter-injector from the blower plenum and discard it.

7. Disconnect the flame detector lead wire and then remove the two (2) Phillip head screws securing the flame detector to the blower plenum (Figure 3). These screws will be used during reassembly, in section 4.3.

8. Remove the flame detector and gasket from the blower plenum and discard them.

Figure 3: Flame Detector Replacement

NOTE The next two steps will remove the blower plenum from between the burner and the blower, HOWEVER, once the plenum is removed, the entire weight of the gas train and blower will be borne by one U-bolt that attaches the gas train to the rails. It is therefore necessary devise a way to support the weight of the blower and blower motor until the plenum is reinstalled. This can be a hoist, a jack, or a piece of lumber cut to size. As an alternative, a special bracket, P/N 23176, may be ordered from AERCO and permanently installed so that the blower is supported during future maintenance procedures. Contact AERCO for details.

9. Use a 3/8” wrench to remove the eight (8) hex nuts and washers securing the blower

plenum to the burner plate.

Elbow

Flame Detector Flame Detector

Gasket

Indexing Washers

(0-3 as needed)

Compression Nut Igniter-Injector

Flame Detector

Staged Ignition Solenoid




Figure 4. Blower Plenum Fasteners 10. Use a 5/16” wrench and 6mm Allen wrench to remove the four (4) hex nuts and washers

securing the blower plenum to the blower (left image), and use a 3/8” wrench to remove the two (2) hex bolts and washers securing the plenum to the plenum rail bracket (right image).

Figure 5: Blower Plenum Removal

11. Move the staged ignition solenoid off to the side and then lift the blower plenum off the unit. The burner gasket and blower gasket are now accessible.

Figure 6: Burner Gasket Removal

Burner Gasket(s)

Nuts (4)

Plenum

Blower

Plenum

Hex Bolts (2)

Hex Nuts (8)

Plenum

Burner Top

Blower Gasket

Plenum Rail Bracket




NOTE Some units may have a single burner gasket while others may have three. In both cases, you must install all three burner gaskets included with the kit, the release gasket, burner gasket and lower release gasket.

12. Remove the existing burner gasket(s)

CAUTION! If the old gasket cannot be removed easily, it may be scraped off, but MUST be removed entirely and without damage to the top surface of the burner. Do NOT use metal tools for scraping as this may leave scratches. Use a vacuum cleaner to remove any remaining pieces or particles. Ensure that NO particles of the old gasket fall into the burner cavity.

13. Replace the burner gasket(s) with the three (3) new gaskets included with the kit, in the order shown below. You must ensure that the Lower Release Gasket (P/N 81185), which features tabs, is placed first, in the lowest position.

Figure 7: Burner Gasket Installation

14. Replace the existing blower gasket with the new blower gasket included with the kit.

15. Replace the blower plenum and secure it to the burner plate with eight (8) nuts and washers removed during disassembly. Tighten to 30 to 35 ft-lbs. of torque, using a crisscross tightening pattern (tighten one, then tighten its opposite) to ensure an even seal.

16. Loosen both hex bolts holding the plenum rail bracket to the rails (see Figure 5), then secure the blower plenum to the plenum rail bracket with two (2) hex bolts and washers removed during disassembly. Once that is complete, tighten both plenum rail bracket hex bolts.

17. Secure the blower plenum to the blower with the four (4) nuts and washers removed in step 9. Torque the bolts to 70 in/lbs.

81173 – Burner Release

81180 – Burner Gasket 81185 – Lower Release Gasket



4.2 Replacing the Igniter-Injector Below are the instructions for installing the new igniter-injector (P/N 58023), including the compression nut and indexing washers.

Replacing the Igniter-Injector

1. Use a 1" wrench to install the new igniter-injector, included with the kit, onto the blower plenum. Use zero to three indexing washers, as needed, so that the igniter-injector’s gas injector tube is positioned within the 120° angle range shown below. Torque the igniter-injector to 170 - 180 in-lbs. DO NOT over tighten.

Figure 8: Igniter-Injector Orientation (viewed from above looking down)

2. Connect the igniter-injector’s gas injector tube to the elbow of the staged ignition solenoid with the new compression nut, included with the kit.

3. Reconnect the igniter-injector cable.

4.3 Installing the New Flame Detector and Flame Detector Gasket The instructions below install the new flame detector (P/N 66034) and flame detector gasket (P/N 81048).

Installing the New Flame Detector and Flame Detector Gasket

1. Install the new flame detector and flame detector gasket, included with the kit, into the appropriate opening and fasten with the two #10-32 Phillips head screws removed during disassembly (see Figure 3).

2. Reconnect the flame detector lead wire to the flame detector terminal.



4.4 Replacing the Air Filter The instructions in this section replace the air filter (P/N 88014).

Replacing the Air Filter

1. Use a flat-tip screwdriver or 5/16” nut driver to loosen the clamp securing the air filter to the inlet flange of the air/fuel valve.

2. Remove the filter and clamp and dispose of them.

Figure 9: Air Filter Replacement

3. Install the new air filter and clamp, included with the kit, and tighten the clamp with a flat-tip screwdriver or 5/16” nut driver.

Gas Train

Air Filter

Air Filter Hose

Clamp

Air/Fuel Valve

Manual shut-off valve



4.5 Replacing the Exhaust Manifold Seal The instructions below replace the exhaust manifold seal (P/N 84040), located between the exhaust manifold and the bottom of the heat exchanger.

Replacing the Exhaust Manifold Seal

1. Place a piece of cardboard or other soft material under the exhaust manifold. This will protect the base of the unit when the exhaust manifold is lowered and slid out from under the heat exchangers.

2. Disconnect the exhaust manifold from the condensate drain in the rear of the unit.

3. Disconnect the condensate trap from its outlet and then remove the condensate trap.

4. Disconnect the exhaust manifold from the exhaust vent.

5. Use a 9/16” wrench to remove all four 3/8-16 hex bolts (1 1/2” long) and washers that attach the exhaust manifold to the bottom flange of the heat exchanger. Do not remove the larger hex bolts that attach the heat exchangers to the base of the unit.

Figure 10: Exhaust Manifold Removal – Partial Right Side View

6. Slide the exhaust manifold out from under the heat exchanger towards the rear of the unit. Check for any signs of deterioration or corrosion.

7. Remove the exhaust manifold seal and, if necessary, remove any remaining adhesive and debris from the exhaust manifold.

8. Peel the self-adhesive paper off the new exhaust manifold seal, included with the kit, and place it on the exhaust manifold with the holes aligned with the exhaust manifold’s threaded holes.

9. Slide the exhaust manifold back under the heat exchanger to its original position.

10. Lift the exhaust manifold until it contacts the underside of the heat exchanger and hold it in place with two 3/8-16 hex bolts, adjusting the position of the exhaust manifold until the bolts aligns with the exhaust manifold’s threaded hole. Partially tighten these bolts.

11. Reinstall and partially tighten the remaining 3/8-16 hex bolts.

12. Fully Tighten all four 3/8-16 hex bolts.

13. Reattach the exhaust vent to the exhaust manifold.

The exhaust manifold is not yet reconnected to the condensate trap. You will complete that step at the end of section 4.6 or 4.7, below.

Exhaust Manifold 3/8-16 Hex Bolts

(4 Each: 2 shown)

Connection to Condensate Trap

Exhaust Vent (partial)



4.6 Replacing the Condensate Trap O-Ring – New Style Trap There are two types of condensate traps in service, and older and a newer style. The instructions in this section apply ONLY to the NEWER style condensate trap. For the older-style trap, see section 4.7.

These instructions replace the external condensate trap O-ring (P/N 84017), located under the condensate trap’s cover. The condensate trap is attached to the exhaust manifold’s condensate drain pipe.

Figure 11: Condensate Trap Location

EXHAUST MANIFOLD

DRAIN PORT

EXHAUST MANIFOLD

3/4” NPT NIPPLE

HOSE CLAMP

TO FLOOR DRAIN

CONDENSATE TRAP (NEW STLE SHOWN)

ADAPTOR THUMBSCREW

TOP COVER THUMB SREWS (4)

1” DIAM. HOSE



Replacing the Condensate Trap O-Ring: New Style 1. Disconnect the external condensate trap from the exhaust manifold drain pipe by loosening

the thumb screw on the trap inlet.

2. Remove the hose connection from the outlet side of the condensate trap.

Figure 12: Newer-Style Condensate Trap – Cross Section 3. Loosen the four (4) thumbscrews securing the top cover to the condensate trap.

4. Remove the old O-ring from the trap.

5. Remove the float and attached float guide from the condensate trap.

6. Thoroughly clean the trap, float, and float guide. Also inspect the drain piping for blockage. If the trap cannot be thoroughly cleaned, replace the trap.

7. After the above items have been inspected and thoroughly cleaned, reassemble the float and float guide into the trap.

8. Install the new O-ring from the kit (P/N 84017).

9. Secure the top cover to the trap with the four thumb screws removed in Step 1.

10. Reassemble the drain hose connection to the outlet of the trap, and then reconnect trap inlet to the exhaust manifold drain by tightening the thumbscrew on the trap inlet. See Figure 11.

THUMB SCREWS (4) COVER

OUTLET

CONDENSATE TRAP O-RING

FLOAT

FLOAT GUIDE

3/4" NPT Port

INLET

INLET ADAPTER INLET O-RINGS



4.7 Replacing the Condensate Trap O-Ring & Orifice Gasket – Old Style Trap The instructions in this section apply ONLY to the OLDER style condensate trap.

These instructions explain how to replace the condensate trap O-ring (P/N 84017), located under the condensate trap’s cover, the condensate trap orifice gasket (P/N 81092), and check and clean the trap. The condensate trap is attached to the exhaust manifold’s condensate drain pipe using two nipples and a union (see Figure 11).

Replacing the Condensate Trap O-Ring & Orifice Gasket: Old Style

1. Disconnect the condensate trap from the exhaust manifold by removing the union between the connecting nipples (Figure 11).

2. Remove the drain hose connection from the outlet side of the condensate trap.

3. Loosen the four (4) thumbscrews securing the top cover to the condensate trap.

Figure 13: Older-Style External Condensate Trap – Cross Section

4. Remove the old O-ring from the trap and discard.

5. Remove the float and float guide from the condensate trap.

6. Remove the old orifice gasket from the trap and discard.

7. Thoroughly clean the trap, float, and float guide then inspect the drain piping for blockage. If the trap cannot be thoroughly cleaned, replace the trap.

8. After the above items have been inspected and thoroughly cleaned, install the new orifice gasket from the kit (P/N 81092), and then reinstall the float and float guide into the trap.

9. Install the new O-ring from the kit (P/N 84017).

10. Secure the top cover to the trap with the four thumb screws removed in Step 1.

11. Reassemble all piping and hose connections to the condensate trap inlet and outlet, and reconnect trap to exhaust manifold drain.

ORIFICE GASKET

OUTLET

INLET

THUMB SCREWS (4) COVER

CONDENSATE TRAP O-RING

FLOAT GUIDE

FLOAT



4.8 Replacing the LWCO Probe and Capacitor Assembly The replacement LWCO probe sensor comes with a capacitor assembly attached. This procedure replaces an old probe assembly with a new probe assembly (P/N 69126).

Replacing the LWCO Probe/Capacitor Assembly

1. Cut the shell harness wire just below the female spade connector (Figure 14). The new LWCO assembly includes a new female connector to crimp onto the shell harness wire.

Figure 14: Removing Old LWCO Probe and Capacitor Assembly

2. Remove the LWCO probe (with capacitor assembly) from the recess well on the hot water outlet piping by unscrewing the brass coupling to which it is attached.

3. Retrieve the new LWCO probe and capacitor assembly from the kit and sparingly apply an NSF approved pipe dope to the threads of the brass coupling (Do NOT use Teflon tape) and install into the probe well vacated by the old LWCO probe.

4. The new LWCO assembly comes with a spare female connector already inserted into the male connector, and this should be crimped onto the stripped end of the shell harness wire from which the old capacitor assembly was cut.

MALE SPADE CONNECTOR

FEMALE SPADE CONN.ON THE SHELL HARNESS WIRE

OLD LWCO PROBE

CUT OFF WIRE TO OLD LWCO

ASSEMBLY HERE

OLD CAPACITOR (COVERED BY LARGE SHRINK TUBING)

PROBE WELL IN HOT WATER

OUTLET PIPING

LWCO PROBE & CAPACITOR ASSEMBLY



4.9 Low Water Cutoff (Lwco) Capacitor Integrity Test The LWCO capacitor should be tested for electrical shorts after it has been replaced. The LWCO capacitor integrity test consists of two parts as described in the next two sections. The first procedure explains how to test for electrical shorting of the LWCO probe capacitor, while the second procedure instructs how to perform the standard Low Water Cutoff test using the C-More controls.

Refer to Figure 15 for an illustration of the LWCO probe assembly and its typical installation.

Figure 15: LWCO Probe Location for BMK2500/3000 (BMK2500 Shown)

4.9.1 Low Water Cutoff (LWCO) - Capacitor Electrical Short Test This test determines if there is an electrical short between the LWCO capacitor and the heat exchanger. Perform the capacitor electrical short test as described below.

LWCO Capacitor Electrical Short Test 1. Turn OFF AC power to the unit.

WARNING! High voltages are used to power these units and so it is required that power applied to these units is removed first before performing the procedure described in this instruction. Serious personal injury or death may occur if this warning is not observed.

(Continued)

LWCO Probe

Capacitor Assembly (Covered By Large Shrink Tubing)

Connector (to Shell Harness)

Plastic Acorn Nut

LWCO Probe Terminal

Hot Water Outlet Pipe

Rear Panel



LWCO Capacitor Electrical Short Test - Continued

2. Remove the Shell Harness Cable (male) connector from the P-5 (female) connector on the rear panel of the C-More controller (see Figure 16).

Figure 16: Removing Shell Harness Cable from P5 Conn. on C-More Rear Panel

3. Using an ohmmeter, connect one ohmmeter probe to the LWCO capacitor terminal on the unit shell as shown on left in Figure 17.

4. Connect the second ohmmeter probe to Pin #6 of Shell Harness Connector (removed from the C-More controller) as shown on right in Figure 17.

Figure 17: Connecting Ohmmeter between LWCO Probe & Shell Harness Cable

Unplug Shell Harness Cable

from P5 Connector

Connect 2nd Lead to PIN #6

19-Pin Shell Harness Cable Connector

LWCO Probe Assembly

Ohmmeter

Connect 1st Lead to LWCO



© AERCO International, Inc., 2014

LWCO Capacitor Integrity Test - Continued

5. Confirm that the ohmmeter does NOT read a short.

NOTE If the ohmmeter reads a short, the capacitor assembly needs to be replaced. Replacement instructions can be found in Section 4.9 or contact AERCO technical support for more information.

6. Remove both ohmmeter probes and reconnect the Shell Harness connector to the P5 connector on the rear of the C-More controller.

4.9.2 Low Water Cutoff (LWCO) - Standard C-More Test Perform the standard Low Water Cutoff test using the C-More controls as described below.

Standard Low Water Cutoff C-More Test

1. Turn on the AC power to the unit.

2. Press the TEST switch on the C-More controller and confirm that the blinking "Low Water Level" message appears on the C-More display within 4 seconds.

3. Press the RESET key, followed by the Clear button, and confirm that the "Low Water Level" message is cleared.

4.10 Returning the Unit to Service

Returning the Unit to Service

1. Reconnect AC power to the unit.

2. Set the ON/OFF switch on the control panel to the On position.

3. Check your work prior to reinstalling the panels, including checking that all gas connections are tight and do not leak.

4. Replace all panels removed during the previous steps.

Change Log: Date Description Changed By

06/06/2014 Rev C: Replaced fuel rod 66020 with 66034 per PIR 1028-3 Chris Blair

09/15/2014 Rev D: Reformatted per latest design standard, added LWCO test instructions, revised condensate trap & LWCO replacement instructions. Curtis Harvey

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