AERCO Packaged WaterWizard Steam-to-Water Heater - Manual (Page 22)

HE-110
1B+ II Water Wizard Water Heaters
OMM-0063_0C Installation, Operation & Maintenance Manual
Page 22 of 50
MC2: 07/26/13 AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, New York 10913 • Phone: 800-526-0288
CHAPTER 6. ROUTINE MAINTENANCE
6.1.
DRAINING THE HEATER
The constant flexure of the Heater coils under varying load conditions automatically provides a
de-scaling action and prevents a buildup of brittle scale. A periodic blowdown (draining) is
required to remove accumulated solids.
After the first 3 months of initial operation, drain the Heater as follows:
(1) Close all stop valves in the Steam inlet and Condensate outlet lines.
(2) In this order, close the stop valves in
a) the hot water outlet line,
b) the recirculation line, if any, and
c) the cold water inlet line.
(3) Carefully open the relief valve (or one of the relief valves) in the Heater top head to relieve
pressure in the Heater shell. If water continues to flow from the relief valve one of the stop
valves either leaks or is not shut off tight. This must be remedied until there is no more flow
through the relief valve.
(4) With the relief valve being held open, (to prevent creating a vacuum in the shell) open the
drain valve and drain the Heater completely.
(5) To refill the Heater and place it back into operation, close the drain valve and proceed
through Steps 1, 12, and 13 under OPERATING PROCEDURES, Chapter 5.
6.2. CHECKING THE DRAINED WATER
The constant flexure of the Heater coils under varying load conditions automatically provides a
de-scaling action and prevents a buildup of brittle scale. A periodic blowdown (draining) is
required to remove accumulated solids.
After the first 3 months of initial operation, drain the Heater as outlined below. Examine the
water being drained.
(a) If the amount of solids appears to be heavy, set a schedule to drain the Heater every 3
months.
(b) If the amount of solids appears to be light, set a schedule to drain the Heater every 6
months.
(c) Even if the amount of solids appears to be very light, set a schedule to drain the Heater
at least once each year.
(d) Also see TROUBLESHOOTING, Chapter 7 and CORRECTIVE MAINTENANCE,
Chapter 8. If de-scaling by thermal shock is required, schedule that procedure in your
ROUTINE MAINTENANCE, Chapter 9.
6.3. CHECKING THE TEMPERATURE CONTROL
Check the temperature control at least once every 3 months. Make any necessary adjustments
per Steps 4 through 8 under OPERATING PROCEDURES, Chapter 5.