AER AM Series Owner's manual

TID-0137_0A
TECHNICAL INSTRUCTIONS
Revised: 01/18/2015
AM Series Boiler
Heat Exchanger Maintenance & Replacement
AM Series Heat Exchanger Module
For all models of AM Series
Boilers, Including:
Water Heaters:
•AM 399W
•AM 500W
•AM 750W
•AM 1000W
Boilers:
•AM 399B
•AM 500B
•AM 750B
•AM 1000B
TID-0137_0A AERCO International, Inc. •100 Oritani Dr. •Blauvelt, NY 10913 Page 1of 36
Ph.: 800-526-0288 01/18/2015

AM Series Boiler Heat Exchanger Maintenance & Replacement
Technical Instruction Document
DISCLAIMER
The information contained in this document 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.
TABLE OF CONTENTS
Material and Tool Requirements.................................................................................31: Preliminary Preparation of the Unit............................................................................52:2.1: Initiating the Burners ...........................................................................................................5
2.2: Closing Water and Gas Connections..................................................................................6
2.3: Draining Water from the Unit .............................................................................................7
2.4: Removing the Covers...........................................................................................................8
2.5: Disconnecting Cables and Wiring Connections.................................................................9
Removing the Heat Exchanger..................................................................................123: Installing the Heat Exchanger...................................................................................194: Final Reassembly........................................................................................................295:5.1: Connecting Cables and Wiring Connections....................................................................29
5.2: Installing the Smaller Wiring Harness..............................................................................29
5.3: Installing the Larger Wiring Harness................................................................................31
5.4: Turning on Services and Leak Testing.............................................................................33
5.5: Turning On Water and Return to Service.........................................................................34
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AM Series Boiler Heat Exchanger Maintenance & Replacement
Technical Instruction Document
Material and Tool Requirements
The following tools and materials are required to perform the heat exchanger replacement
procedure.
Piece of Wood (roughly 20” x 2-1/2” x 1/2”)
10mm Nut Driver (19” Length) or 10mm Socket Wrench and Extension
Phillips Screwdriver (TOR x 20”)
46mm Pipe Wrench or Adjustable Wrench
30mm Pipe Wrench or Adjustable Wrench
Wrench (10mm)
Gasket
(P/N 60702096)
Gasket
(P/N 60702097)
Gasket x2 (1-1/4” Dia.)
(P/N 60701007)
Gasket (3/4” Dia.)
(P/N 607001006)
Silicone Grease
Scotch Tape
(or equivalent)
Air Compressor
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AM Series Boiler Heat Exchanger Maintenance & Replacement
Technical Instruction Document
Figure 1-1: AM Series Rear Panel Features
NOTE
These instructions can be used for maintenance of an existing
functional heat exchanger module or can be used to replace a
defective heat exchanger module with a new one. Refer to the
notes in the instructions for specific instructions.
WATER
SUPPLY
HEADER
WATER RETURN
HEADER
WATER RETURN
INLET
WATER SUPPLY
OUTLET
WATER RETURN
DRAIN VALVE
WATER SUPPLY
DRAIN VALVE
GAS SUPPLY
INLET
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AM Series Boiler Heat Exchanger Maintenance & Replacement
Technical Instruction Document
Preliminary Preparation of the Unit
2.1: Initiating the Burners
To prepare the boiler or water heater for the maintenance procedure perform the following:
Initiating the Units Burners
1. Ensure power is supplied to the unit, then turn on the unit by placing the power switch to
the ON position (Figure 2-1).
Figure 2-1: Turning the Power Switch to ON
2. Wait for the unit to finish initializing.
3. Increase the unit setpoint to the maximum by pressing and holding down the Setpoint +
Button on the front panel controls until maximum is reached.
4. Press the Reset Button.
5. The Setpoint Icon will blink while setpoint temperature is rising and the burners are
initializing. As burners finish initializing, each one will be indicated by the circled number
in the upper left of the display (Figure 2-2).
Figure 2-2: AM Series Controls and Display
6. Once all the burner indicator icons are showing in the display, turn the boiler power
switch to OFF, as this means all automatic valves are now locked in the open position.
POWER SWITCH
SETPOINT +
BUTTON
BURNER
INDICATOR
ICONS
SETPOINT
ICON
RESET
BUTTON
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AM Series Boiler Heat Exchanger Maintenance & Replacement
Technical Instruction Document
2.2: Closing Water and Gas Connections
Closing Water and Gas Connections
1. Turn OFF the water supply and return pipe valves. See Figure 2-3.
Figure 2-3: Turn OFF Water Supply and Return Pipe Valves
2. Turn OFF the gas supply valve. See Figure 2-4.
Figure 2-4: Turn OFF Gas Supply Valve
3. Completely remove power from the unit by shutting off electrical power upstream from the
boiler.
WARNING!
High voltages are used in AM Series systems. It is required that all
power applied to these boilers is removed first before performing any
of the procedures described in this document. Use extreme care
when accessing circuits and electrical connections within the
equipment. Serious personal injury or death may occur if this warning
is not observed.
WATER RETURN
VALVE: OFF
WATER SUPPLY
VALVE: OFF
GAS SUPPLY
VALVE:
OFF
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AM Series Boiler Heat Exchanger Maintenance & Replacement
Technical Instruction Document
2.3: Draining Water from the Unit
Follow the procedure below to drain the unit of water.
Draining Water from the Unit
1. Connect the air compressor hose to the drain valve of the water return header. See
Figure 2-5.
2. Connect a drain hose to the drain valve of the water supply header. See figure 2-5.
Figure 2-5: Connections for Draining Water from the Unit
3. While positioning the drain hose outlet in an appropriate receptacle or drain, slowly open
the water return drain valve to allow compressed air into the unit.
CAUTION!
Monitor the AM Series relief valve so as not to release too much
pressure from the air compressor into the unit or the pressure
relief valve might be tripped.
WARNING!
Water drained from the boiler may be very hot. Use caution to
avoid scalding.
CONNECT AIR
COMPRESSOR
HOSE TO
WATER RETURN
DRAIN VALVE
CONNECT DRAIN
HOSE TO
WATER SUPPLY
DRAIN VALVE
DRAIN HOSE
AIR
COMPRESSOR
HOSE
WATER SUPPLY
DRAIN VALVE
WATER
RETURN
DRAIN VALVE
DRAINING
WATER
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AM Series Boiler Heat Exchanger Maintenance & Replacement
Technical Instruction Document
2.4: Removing the Covers and Intitial Diassembly
In order to remove the unit covers, refer to Figure 2-6 and follow the steps below:
Removing the Covers and Initial Disassembly
1. Lift up, by hand, the Top Cover “A”.
2. Remove two Front Cover screws “B”.
3. Pull back the upper part of Front Cover “C” for 2 inches, then pull it up for one inch and remove
it from the unit.
4. Pull back upper part of Bottom Cover “D” for 2 inches, then pull it up for one inch and remove it
from the unit.
“A”Top Cover
(E)
“B”Front Cover
Screws (2 each)
“C”Front Cover
“D”Bottom Cover
Figure 2-6: Removing the Top and Front Covers
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AM Series Boiler Heat Exchanger Maintenance & Replacement
Technical Instruction Document
Removing the Covers and Initial Disassembly - Continued
5. Remove the plastic blower cover by pulling it from the blower. See Figure 2-7.
6. Pull out the air inlet piece and attached hose from the blower inlet. See Figure 2-7.
Figure 2-7: Removing the Blower Cover & Air Inlet Connector/Hose
2.5: Disconnecting Cables and Wiring Connections
Disconnecting Cables and Wiring Connections
Figure 2-8: Unscrewing Gas Valve Connector & Cutting Harness Cable Tie
1. Unscrew the Phillips head screw from the gas valve connector but leave it plugged in for
now. See Figure 2-8.
2. To the right of the blower, cut the cable tie that ties the cables together. See Figure 2-8.
2
6
5
1
6
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AM Series Boiler Heat Exchanger Maintenance & Replacement
Technical Instruction Document
Disconnecting Cables and Wiring Connections - Continued
3. Unplug the two blower power harnesses from the blower.
4. Perform the following to remove the igniter assembly from the heat exchanger:
a) Detach igniter cables from the two igniter terminals.
b) Detach the igniter power harness from the connector on the igniter.
c) Detach the igniter ground wire lug from the screw on the burner flange.
d) Remove the two igniter mounting screws.
e) Remove the igniter assemblyfrom the heat exchanger.
5. Disconnect the two harness connectors from the high limit thermostat.
6. Disconnect the harness from the pressure sensor (Module 1 only).
7. Disconnect the wires from the flow meter.
8. Disconnect the motorized valve power harness (see Figure 2-10).
9. Disconnect the cable from the flue gas flow sensor (red).
10. Disconnect the cable from the flue gas high limit sensor (blue).
11. Disconnect cable from the flame detector terminal on left side of blower flange.
Figure 2-9: Cable Harness Disassembly
1
7
6
b
e
c
3
d
5
a
9
10
11
BURNER
FLANGE
BLOWER
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AM Series Boiler Heat Exchanger Maintenance & Replacement
Technical Instruction Document
Disconnecting Cables and Wiring Connections - Continued
Figure 2-10: Disconnecting Power Cable of Motorized Valve
12. Gather all wire harnesses from under and around the heat exchanger and drape onto the open
panel door so that they are kept away from the heat exchanger (Figure 2-11).
Figure 2-11: Draping Cables and Harnesses onto Panel Door
13. This ends the wire harness preparation. Proceed to the next section for disassembly of the
heat exchanger from the unit.
8
OPEN PANEL
DOOR
STEP 12: CABLES &
HARNESSES
MOTORIZED
VALVE
MOTORIZED
VALVE CABLE
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AM Series Boiler Heat Exchanger Maintenance & Replacement
Technical Instruction Document
Removing the Heat Exchanger
Removing the Heat Exchanger
NOTE
Refer to Figure 3-1 for Steps 1-3.
1. Remove nut on left side of the gas valve with the 46mm wrench. Ensure that the gasket
located between pipe and gas well is retained for later reassembly.
2. Remove nut at lower right position on burner flange with short 10mm wrench, as shown in
Figure 3-1.
3. Remove the other three nuts, as indicated in Figure 3-1, with the 19” long 10mm socket
wrench.
Figure 3-1: Disconnections to Remove Burner/Blower Assembly
4. Carefully remove the entire blower/burner assembly from the heat exchanger, as shown in
Figure 3-2.
Figure 3-2: Removing the Blower/Burner Assembly from the Heat Exchanger
STEP 1: REMOVE GAS VALVE
NUT w/30mm PIPE WRENCH &
RETAIN THE GASKET!
STEP 2: REMOVE
THIS BURNER
NUT with SHORT
10mm WRENCH
BURNER/BLOWER
ASSEMBLY
HEAT
EXCHANGER
STEP 3: REMOVE THE
OTHER THREE
BURNER NUTS w/19”
LONG 10mm WRENCH
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AM Series Boiler Heat Exchanger Maintenance & Replacement
Technical Instruction Document
Removing the Heat Exchanger - Continued
5. Perform the following to remove the igniter assembly from the heat exchanger below the one
being removed:
NOTE
Refer to Figure 2-10 for image of igniter removal details.
a) Detach igniter cables from the two igniter terminals.
b) Detach the igniter power harness from the connector on the igniter.
c) Detach the igniter ground wire lug from the screw on the burner flange.
d) Remove the two igniter mounting screws.
e) Remove the igniter assembly from the heat exchanger.
6. Remove the two (or four) screws holding the lower bracket between heat exchangers.
7. Remove the two (or four) screws holding the upper bracket between heat exchangers. This
bracket is not present on the uppermost heat exchanger.
Figure 3-3: Removing Lower Igniter, Flow Sensor, and Brackets
STEP 6: REMOVE THE TWO
TO FOUR SCREWS TO
REMOVE LOWER BRAKET
(NOT PRESENT ON LOWEST
HEAT EXCHANGER)
STEP 7: REMOVE THE TWO
TO FOUR SCREWS TO
REMOVE UPPER BRAKET
(NOT PRESENT ON TOP
HEAT EXCHANGER).
STEP 5:
REMOVE LOWER IGNITER
ASSEMBLY
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AM Series Boiler Heat Exchanger Maintenance & Replacement
Technical Instruction Document
Removing the Heat Exchanger - Continued
8. If the pressure sensor is installed on the heat exchanger being maintenance or on the heat
exchanger below it, unscrew it and set aside for later reassembly. Figure 3-4 shows the
location of the pressure sensor as being on the heat exchanger below the one being serviced.
Figure 3-4: removal of the Pressure Sensor
9. Use a large plastic bag to cover the all the other heat exchanger assemblies below the one
being removed, as shown in Figure 3-5. This is to prevent unit components from contamination
by possible residual leakage when disconnecting the water connections to the heat exchanger.
Ensure that if the pressure sensor opening is below, it is covered
Figure 3-5: Placing Protective Plastic over Lower Components
TAPE BAG AGAINSTSIDE OF
HEAT EXCHANGER HERE
TAPE BAG HIGH
AGAINST INSIDE OF
THE UNIT HERE
TUCK BAG UNDER THE HEAT
EXCHANGER LOWER EDGE
ENSURE ALL LOWER
COMPONETS ARE
COMPLETELY COVERED
STEP 8:
PRESSURE
SENSOR
IF THE PRESSURE
SENSOR WAS REMOVED
FROM HERE, BE SURE
TO COVER OPENING.
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AM Series Boiler Heat Exchanger Maintenance & Replacement
Technical Instruction Document
Removing the Heat Exchanger - Continued
10. Completely loosen the water supply nut, as shown in Figure 3-6, using the 46mm wrench.
11. Completely loosen the water return nut on the outlet side of the flow meter, as shown in
Figure 3-6, using the 46mm wrench.
Figure 3-6: Loosening the Return and Supply Connection Nuts
12. At the rear of the unit, completely loosen the nut for the water supply of the heat exchanger
being replaced using the 46mm wrench, as shown in Figure 3-7.
Figure 3-7: Loosening the Water Supply Nut at Rear of Unit
STEP 10:LOOSEN THE WATER
SUPPLY NUT COMPLETELY
WITH 46mm WRENCH
STEP 11:
LOOSEN THE
WATER RETURN NUT
COMPLETELY WITH
46mm WRENCH AND
RETAIN THE O-RING
GASKET!
STEP 12:COMPLETELY
LOOSEN THE WATER
SUPPLY NUT AT THE
REAR OF THE UNIT
WITH 46mm WRENCH.
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AM Series Boiler Heat Exchanger Maintenance & Replacement
Technical Instruction Document
Removing the Heat Exchanger - Continued
13. Place the piece of wood under the left side of the heat exchanger as shown in Figure 3-8. It
should be placed precisely as shown in the right side image to prevent damage to the module
below when removing the heat exchanger.
Figure 3-8: Placing Piece of Wood under Left-Side of Heat Exchanger
14. There are four 10mm bolts affixing the heat exchanger module to the inside rear panel of the
unit. Completely remove the two bolts on the left side, as indicated in Figure 3-9, using the 19”
long 10mm nut driver.
15. Loosen (but do not remove) the two bolts on the right side, as indicated in Figure 3-9, using the
19” long 10mm nut driver.
Figure 3-9: Removing and Loosening Bolts Affixing Heat Exchanger to Rear Panel
STEP 13:
PIECE
OF WOOD
STEP 14:
COMPLETELY
REMOVE THE TWO
BOLTS ON LEFT
WITH 19” LONG
10mm NUT DRIVER.
STEP 15:LOOSEN
(DO NOT REMOVE)
THE TWO BOLTS
ON RIGHT WITH 19”
LONG 10mm NUT
DRIVER.
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AM Series Boiler Heat Exchanger Maintenance & Replacement
Technical Instruction Document
Removing the Heat Exchanger - Continued
16. Remove the four 10mm bolts affixing gas inlet to the gas piping, as shown in the left image of
Figure 3-10.
17. After removing the bolts, pull the entire gas inlet piping to the right (as you are facing the rear of
the unit), as indicated in right image of Figure 3-10.
Figure 3-10: Disconnecting 10mm Bolts from Gas Connection at Rear Panel
18. The heat exchanger may now be removed by first pushing to the left to disengage from the two
loosened bolts and flue connections on the right, and then pulling it straight out from the unit.
See Figure 3-11.
Figure 3-11: Removing Heat Exchanger from the Unit
NOTE
Retain the O-Ring (Figure 3-12) from the flow meter connection, for
later reassembly, during removal of the heat exchanger.
RETAIN
O-RING
PUSH LEFT
STEP 16:REMOVE
FOUR 10mm BOLTS
STEP 17:PULL
GAS TRAIN
TOWARD YOU.
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AM Series Boiler Heat Exchanger Maintenance & Replacement
Technical Instruction Document
Removing the Heat Exchanger - Continued
Figure 3-12: Retain Flow Meter O-Ring
19. If the heat exchanger is being replaced with a new one, use the 46mm wrench to loosen the
nut attaching the water return piping to the old heat exchanger, as indicated in Figure 3-13 and
install it onto the new heat exchanger.
Figure 3-13: Removing Water Return Pipe & Flow Meter from Old Heat Exchanger
20. Remove the flue gasket, as shown in Figure 3-14, and replace if necessary.
21. Remove the lower smaller flue gasket, as shown in Figure 3-14, and replace if necessary.
Figure 3-14: Removing the Two Gaskets from the Flue
RETAIN
O-RING
FLOW
METER
STEP 20:
REMOVE FLUE
GASKET
STEP 21: REMOVE
CONDENSATE DRAIN
GASKET
STEP 19:USE 46mm
WRENCH TO REMOVE,
THEN RECONNECT TO
NEW HEAT EXCHANGER.
NOTE!
This instruction only
applies if the heat
exchanger is being
replaced with a new
one.
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AM Series Heat Exchanger Replacement
Technical Instruction Document
Installing the Heat Exchanger
Installing of the Heat Exchanger
1. If the flue and/or condensate gaskets are being replaced, use a brush to liberally apply a
silicone lubricant to the flanges of the affected inlet(s), as shown in Figure 4-1.
Figure 4-1: Applying Silicone Lubricant to Upper and Lower Flue Openings
2. Retrieve the two replacement flue gaskets (P/N 60702097 & 60702096) from the heat
exchanger maintenance kit.
3. Install the upper larger gasket (P/N 60702097), ensuring that seals inside and outside the
opening are correctly mated to the flue inlet flange. Orient with the “notch” in the gasket
facing toward you, and match the arrow on the gasket to the square mark on the flue inlet
flange (Figure 4-2).
4. Install the lower smaller gasket (P/N 60702096), ensuring that seals inside and outside the
opening are correctly mated to the flue inlet flange.
Figure 4-2: Fitting the Gaskets Securely Inside and Outside the Flange
STEP 3:
INSTALL FLUE
GASKET
STEP 4: INSTALL
CONDENSATE DRAIN
GASKET
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AM Series Boiler Heat Exchanger Maintenance & Replacement
Technical Instruction Document
Installing of the Heat Exchanger - Continued
NOTE
Ensure that the upper flue gasket is oriented so that the arrow
mark on the rim of the gasket is lined up with the square mark on
the flue inlet flange. See Figure 4-3).
Figure 4-3: Upper Flue Inlet Gasket Orientation Marks
5. If the heat exchanger is NOT being replaced, but just receiving maintenance, then carefully
tip over the heat exchanger letting the excess water drain from the water supply outlet, as
shown in Figure 4-4.
Figure 4-4: Draining Excess Water from the Heat Exchanger
SQUARE
MARK
ARROW
MARK
FLUE
INLET
GASKET
NOTE!
Step 5 only applies if the
heat exchanger is being
serviced but NOT replaced.
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