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Cleaning and Flushing
Cleaning and flushing of the piping system is the single most
important step to ensure proper start-up and continued efficient
operation of the system.
WARNING
To avoid possible injury or death due to electrical shock, open
the power supply disconnect switch and secure it in an open
position before flushing system. Install lockout tag.
Follow the instructions below to properly clean and flush the
system:
1.
Verify electrical power to the unit is disconnected and lockout
tag installed.
2.
Install the system with the supply hose connected directly to
the return riser valve. Use a single length of flexible hose.
3.
Open all air vents. Fill the system with the water. DO NOT
allow system to overflow. Bleed all air from the system.
Pressurize and check the system for leaks and repair
appropriately.
4.
Verify all strainers are in place. Start the pumps, and
systematically check each vent to ensure all air is bled from
the system.
5.
Verify make-up water is available. Adjust make-up water
appropriately to replace the air which was bled from the
system. Check and adjust the water/air level in the expansion
tank.
6.
Raise the loop temperature to approximately 85F. Open the
drain at the lowest point in the system. Adjust the make-up
water replacement rate to equal the rate of bleed.
7.
Refill the system and add trisodium phosphate in a proportion
of approximately one pound per 150 gal. of water (or other
equivalent approved cleaning agent).
CAUTION
To avoid possible damage to a plastic (PVC) piping system, do
not allow temperatures to exceed 110°F.
8.
Raise the loop temperature to 100F. Circulate the solution
for a minimum of 8 to 24 hours. At the end of this period,
shut off the circulating pump and drain the solution. Repeat
system cleaning if desired.
9.
When the cleaning process is complete, remove the
short-circuited hose. Reconnect the hoses to the proper
supply, and return the connections to each of the units. Refill
the system and bleed off all air.
10. Test the system pH with litmus paper. The system water
should be slightly alkaline (pH of 7.5 to 8.5). Add chemicals,
as appropriate, to maintain acidity levels.
11. When the system is successfully cleaned, flushed, refilled and
bled, restore power.
12. Check the main system panels, safety cutouts and alarms. Set
the controls to properly maintain loop temperatures.
CAUTION
DO NOT use "Stop Leak" or any similar chemical agent in
this system. Addition of these chemicals to the loop water will
foul the system and inhibit unit operation.
Antifreeze
In areas where entering loop temperatures drop below 40°F or
where piping will be routed through areas subject to freezing,
antifreeze is needed.
Alcohols and glycols are commonly used as antifreeze agents.
Freeze protection should be maintained to 15°F below the lowest
expected entering loop temperature. For example, if the lowest
expected entering loop temperature is 30°F, the leaving loop
temperature would be 22°F to 25°F. Therefore, the freeze
protection should be at 15°F (30°F – 15°F = 15°F).
IMPORTANT: All alcohols should be pre-mixed and pumped
from a reservoir outside of the building or introduced under
water level to prevent alcohols from fuming.
Calculate the total volume of fluid in the piping system.
(See Table 9.) Use the percentage by volume in Table 10 to deter-
mine the amount of antifreeze to use. Antifreeze concentration
should be checked from a well mixed sample using a hydrometer
to measure specific gravity.
FREEZE PROTECTION
The freeze sensor input is active at all the times. There are 2
configurable freeze points, 26°F and 15°F. Refer to Configure
Unit Control Componentson page 21 for more information regard-
ing the freeze sensors. The unit will enter a soft lockout until the
temperature climbs above the set point and the anti-short cycle
time delay has expired. The freeze sensor will shut the compressor
output down after 30 seconds of water flow loss and report a
freeze condition. It is recommended to have a flow switch to pre-
vent the unit from running if water flow is lost.
Table 9 — Approximate Fluid Volume (gal.)
per 100 Ft of Pipe
PIPE
Copper
Rubber Hose
Polyethylene
LEGEND
IPS
— Internal Pipe Size
SCH — Schedule
SDR — Standard Dimensional Ratio
NOTE: Volume of heat exchanger is approximately 1.0 gallon.
Table 10 — Antifreeze Percentages by Volume
ANTIFREEZE
Methanol (%)
100% USP Food Grade
Propylene Glycol (%)
25
DIAMETER (in.)
VOLUME (gal.)
1
1.25
1.5
1
3/4 IPS SDR11
1 IPS SDR11
1-1/4 IPS SDR11
1/2 IPS SDR11
10.9
2 IPS SDR11
18.0
1-1/4 IPS SCH40
1-1/2 IPS SCH40
10.9
2 IPS SCH40
17.0
MINIMUM TEMPERATURE FOR
FREEZE PROTECTION (°F)
10
15
20
25
21
16
38
30
22
4.1
6.4
9.2
3.9
2.8
4.5
8.0
8.3
25
10
15
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