FORM 155.32-ICOM2.EN.UL
SECTION 7 – MAINTENANCE
ISSUE DATE:1/10/2018
JOHNSON CONTROLS
145
WATER QUALITY CONTROL
Use the following guidelines to be sure of the highest water quality control standards:
• Limit the water pressure to the maximum safe working pressure for chilled/hot and
cooling water.
• Install a 10-20 or finer mesh strainer in the chilled/hot and cooling water piping.
• Install a thermometer and a pressure gauge in the inlet and the outlet of the chilled/
hot and cooling water piping.
• Install tapping (with valve) for chemical cleaning of the inlet and the outlet of the
chilled/hot and cooling water piping.
• Install an air vent valve at the highest part of the piping and a drain valve at the lowest
part of the piping.
• Replace the water regularly and control the water quality. Operating the chiller-heater
for long periods of time with low quality water will cause corrosion and form scaling.
• Make sure the shut off valves installed at the chiller-heater inlet of the chilled/hot, and
cooling water are completely open.
• Install an expansion tank on the hot water line if the hot water is a closed system.
CHEMICAL WATER TREATMENT
Since the mineral content of the water circulated through the evaporator, condenser, and
absorbers varies, the water used may corrode the tubes or deposit heat resistant scaling
inside the tubing.
Perform a chemical analysis of the water before the system is installed. Consult a reliable
water treatment company to determine if treatment is necessary. If treatment is necessary,
the water treatment company can provide treatment for the water to help prevent damage
to the tubes.
REPLACEMENT OF WATER
Since the cooling water system can be polluted by various factors, it must be cleaned and
the water it in must be replaced approximately every 6 months. If the water is not treated by
the cooling tower, the recommended interval to replace the cooling water is:
• District polluted with sulfurous acid gas --- 5 days
• Common district --- 10 days
If the water is blown manually or automatically, the replacement period may be lengthened
as follows.
• District polluted with sulfurous acid gas --- 1 month
• Common district --- 1 month
NOTE: If the chiller-heater runs without the valves completely open, a strong Eddy
current can be generated. This turbulence may cause damage in the water chamber
case and the copper tube of the chiller-heater. If you need to adjust the flow rate of the
chilled/hot and the cooling water, be sure to adjust the valves installed at the outlet
side of the chiller-heater.
