Dunkirk Q90-100, Installation, Operation & Maintenance Manual

Page: 37 / 56

37
Water Quality, Water Treatment and Freeze
Protection - see Appendix A
Filling Boiler With Water And Purging Air For
Systems With Diaphragm Type Expansion Tanks
Refer to the appropriate diagrams, “Near Boiler Piping” on
page 11 for more information.
1.
Close all zone service valves on the supply and return
piping. Open the feed valve and fi ll boiler with water.
Make sure air vent is open. Hold relief valve open until
water runs air free for fi ve 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
fi rst zone. Open the purge valve on the fi rst zone. Feed
water will fi ll 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.
Purging Air For Systems With Conventional
Closed Type Expansion Tanks:
Refer to the appropriate diagrams “Near Boiler Piping” on
page 11 for more information.
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 fi ll
boiler with water. Hold relief valve open until water
runs air free for fi ve 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
fi rst zone. Open the purge valve on the fi rst zone. Feed
water will fi ll 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.
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