AERCO Esteem Boiler with EZ-Set Controller - Manual (Page 32)

GF-135
Esteem 399 Low NOx Boiler Chapter 5
OMM-0089_0A Installation, Operation & Maintenance Manual Boiler Piping
Figure 5-1: Pressure Relief valve and Boiler Drain Valve Installation
5.3 BOILER AIR VENT
This boiler is supplied with a special automatic air vent that will provide reliable operation in
purging air from the boiler. The hygroscopic cap supplied with the automatic air vent MUST
remain tight at all times on the air vent body. The hygroscopic cap has a membrane which
expands upon contact with water and seals the air vent until the membrane dries up due to new
air forming in the air vent.
• Make sure to fully tighten the cap on the air vent on initial installation.
• Never loosen the hygroscopic cap to allow air to escape the air vent. Air will exit with the
cap fully tightened in place.
• If the hygroscopic cap is not fully tightened, water may leak from the cap. Simply tighten
the cap securely.
5.4 LOW WATER CUTOFF DEVICE
• The Esteem boiler is equipped with a factory installed pressure switch type Low Water Cut Off
device.
• The minimum operating system pressure allowable with this device is 10 psig.
• Check local codes if a Low Water Cutoff Device is required. If so, determine if this device
meets the requirements of the local codes.
WARNING!
The Esteem boiler control system senses the system water
temperatures entering and exiting the heat exchanger to provide
protection against low water conditions where local codes and
jurisdiction do not accept a pressure device for low water
protection, they may accept these integral control functions as a
means of providing low water protection.
(Field Supplied)
Page 32 of 188 AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 OMM-0089_0A
MC1 06/19/14 Ph.: 800-526-0288