37
3.
Reinstall boiler water, gas and electric connections.
4.
Thoroughly purge the air from the boiler and system.
Only after system is purged of air and filled with water
should the boiler be started. Follow the
recommended system start-up procedure in the
installation manual.
HEAT EXCHANGER REPLACEMENT [AM-100 & 150]
1.
Turn gas supply OFF at upstream supply valve. Turn
electrical supply OFF at wall disconnect switch.
Disconnect gas pipe, 115V power and thermostat
lines at boiler.
2.
Isolate boiler from hydronic system and drain boiler.
Disconnect supply and return water piping and
condensate drain line.
3.
Cut air intake and exhaust lines leaving at least 2"
on each side of the cut to receive a coupling for
reassembly.
4.
Remove the boiler from the installation and locate
it for further disassembly.
5.
Remove the electric box from the boiler:
a.
Disconnect the yellow and orange leads from
the gas valve and blue and brown leads from the
high limit.
b.
Remove the 1/8" O.D. copper regulator vent
pressure line at the gas valve.
c.
Inside the electric box, exiting the wire harness
disconnect:
1. Green ground wire from ground screw
2. White lead from terminal #4 on terminal strip
3. Ignition wire lead from the GC-4 ignition spud
4. Red lead - cut wire inside electrical box and
splice later.
5. Copper pressure lines exiting the wire
harness. Separate from plastic tubing and
compression fitting respectively. Bend tubes
straight and away from electric box.
d.
Unscrew bushing from end of wire harness.
e.
Remove the four screws securing box to boiler
jacket and lift the box away from the boiler - set
aside. (See fig. 10 and 11).
6.
Disconnect the gas valve and gas lines, unscrew the
air inlet and exhaust adapters, detach the high limit
and unscrew the well from the boiler.
7.
Remove all jacket screws and lift off the top lid and
jacket parts from the boiler. (Refer to fig. 9).
8.
Remove the Air Cushion Chamber (ACC)
a.
Remove the 4-1/4" nuts securing the top lid. Lift
off the lid and the spring and set them aside.
b.
Lift the fan assembly, disconnect the motor
leads. Remove assembly and set aside.
c.
Disconnect the gas line flare nut from the Gas
Cushion Chamber (GCC) and the compression
nut from the 3/16" copper pressure sensing line.
d.
Disconnect the green ground lead from the
Combustion Chamber and the ignition lead from
the spark plug.
e.
From the underside of the ACC, unscrew the
4-1/4" nuts. LIFT OFF THE ACC.
9.
Remove the (4) four nuts securing the Gas Cushion
Chamber (GCC) from the Combustion Chamber. Lift
off the GCC and remove the flame trap from the
Combustion Chamber - set them aside.
10. Remove the three nuts securing the bottom boiler
flange to the Exhaust Cushion Chamber (ECC). Lift
the Heat Exchanger off the ECC. (It may be
necessary to pry the assemblies apart to break the
seal).
BOILER REASSEMBLY [AM-100/-150]: Check that
ECC is centered in the base pan and the 3 tabs in the
base are pointed up to keep the ECC in position.
1.
Remove seal from the ECC and clean the top
surface of the chamber. Check the inside of the
chamber and remove any loose particles.
2.
Place a new seal on the ECC. To assure a leak
tight seal, run a 1/4" wide bead of silicone on top of
the seal.
3.
Position the “new” Heat Exchanger by aligning the
water supply and return connections with the
condensate drain fitting and the 3 holes in the bottom
flange with the studs in the ECC. Drop into place.
Install the washers and nuts. Alternately and
incrementally tighten the nuts to a maximum of
5 ft.-lb. (Overtightening can crack the ECC).
4.
Run a 1/8" dia. bead of silicone on the top edge of the
heat exchanger shell. Place the silicone “U” gasket
over the shell. Apply silicone to each end of the
gasket and butt the ends together. If the “U” gasket
is too long, cut one end to maintain a butt fit. Position
the gasket so that the bottom is a flat plane on top of
the Heat Exchanger.
5.
Place the flame trap in the Combustion Chamber,
screw the (4) four studs into Combustion Chamber
flange, position the GCC gasket over the studs.
