Carrier BW9 Series Installation Instructions Manual Download Page 17

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c. Follow the antifreeze manufacturer’s instructions on

determining proper ratio of antifreeze to water for the

expected low temperature conditions, and for
maintaining the quality of the antifreeze solution from
year to year. Improperly maintained antifreeze

solutions will gradually lose their ability to protect the
aluminum boiler from corrosion.

The recommended premixed antifreeze solution is

INTERCOOL NFP--50

. This product is sold direct to

installing contractors by the antifreeze manufacturer.

Please contact Interstate Chemical Company, New
York Customer Service at 1--800--422--2436 to

purchase. Use of an alternate manufacturer’s premix
antifreeze is acceptable if the product specifications are
compatible with those of the recommended premix

antifreeze and the antifreeze is compatible with type
356 T6 aluminum. Use of incompatible antifreeze

could damage the heat exchanger and could void
product warranty.

The antifreeze must be maintained per the
specifications of the manufacturer. Failure to do so
could result in the warranty being voided. Follow the

antifreeze manufacturer’s instructions on determining
the proper ratio of antifreeze to water for the expected

low temperature conditions and for maintaining the
antifreeze solution from year to year.

DO NOT USE AUTOMOTIVE ANTIFREEZE

, as

the type of corrosion inhibitors used will coat the
boiler’s heat transfer surfaces and greatly reduce

capacity and efficiency.

f. Use of antifreeze in any boiler will reduce heating

capacity by as much as 10--20 percent, due to differing
heat transfer and pumping characteristics. This must be
taken into consideration when sizing the heating

system, pump(s) and expansion tank. Consult
antifreeze manufacturer’s literature for specific

information on reduced capacity.

g. Water content of the boiler is 2.6 gallons (10 liters).

STEP 2

—

Filling Boiler with Water and Purging Air for

Systems with Diaphragm Type Expansion Tanks

Refer to appropriate “Near Boiler Piping” diagrams.

1. Close all zone service valves on the supply and return

piping. Open the feed valve and fill boiler with water.

Make sure air vent is open. Hold relief valve open until
water runs air free for five seconds to rapidly bleed air

from boiler, then let the relief valve snap shut.

2. Open the zone service valve on the

supply

pipe for the

first zone. Open the purge valve on the first zone. Feed

water will fill the zone, pushing air out the purge valve.
Close the purge valve when the water runs air free. Close

the zone service valve.

3. Repeat step 2 for all remaining zones.
4. Open all service valves. Any air remaining trapped in the

return lines between the service valves and the boiler will
be pushed towards the air vent when the boiler is placed in

operation.

5. Inspect piping system. Repair any leaks immediately.

STEP 3

—

Filling Boiler with Water and Purging Air for

Systems with Conventional Closed Type Expansion Tanks

Refer to appropriate “NEAR BOILING PIPING” diagrams.

1. Close all zone service valves on the supply and return

piping and close the expansion tank service valve. Drain

expansion tank. Open the feed valve and fill boiler with
water. Hold relief valve open until water runs air free for
five seconds to rapidly bleed air from boiler, then let the

relief valve snap shut.

2. Open the zone service valve on the supply pipe for the

first zone. Open the purge valve on the first zone. Feed
water will fill the zone, pushing air out the purge valve.
Close the purge valve when the water runs air free. Close

the zone service valve.

3. Repeat step 2 for all remaining zones.
4. Open the expansion tank service valve and the tank vent.

Fill the tank to the proper level and close the tank vent.

Remove the handle from the expansion tank service valve
so the homeowner doesn’t accidentally close it.

5. Open all service valves. Any air remaining trapped in the

return lines between the service valves and the boiler will
be pushed towards the expansion tank when the boiler is

placed in operation.

6. Inspect piping system. Repair any leaks immediately.

NOTE

: DO NOT use stop leak compounds. Leaks in threaded

connections in the aluminum boiler sections must be

repaired