Specifications

IM 1059-1 / Page 11 of 36
Cleaning & Flushing System
1. Priortorstoperationofanyconditioner,thewater
circulatingsystemmustbecleanedandushedofall
construction dirt and debris.
If the conditioners are equipped with water shutoff
valves, either electric or pressure operated, the
supply and return runouts must be connected
together at each conditioner location. This will
prevent the introduction of dirt into the unit. See
Figure 15.
Figure 15: Supply & Return Runouts Connected
Together
2. Fill the system at the city water makeup connection
withallairventsopen.Afterlling,closeallair
vents. The contractor should start main circulator
with the pressure reducing valve open. Check vents
in sequence to bleed off any trapped air, ensuring
circulation through all components of the system.
Power to the heat rejector unit should be off, and the
supplementary heat control set at 80°F (27°C).
While circulating water, the contractor should
check and repair any leaks in the piping. Drains at
the lowest point(s) in the system should be opened
for
initialushandblowdown,makingsurecity
waterllvalvesaresettomakeupwateratthe
same rate. Check the pressure gauge at pump
suction and manually adjust the makeup to hold the
same positive steady pressure both before and after
opening the drain valves. Flush should continue for
at least two hours, or longer if required, to see clear,
clean drain water.
3.
Shut off supplemental heater and circulator pump
and open all drains and vents to completely drain
down the system. Short circuited supply and return
runouts should now be connected to the conditioner
supply and return connections. Do not use sealers at
the
swivelareconnectionsofhoses.
Return Runout
Supply Runout
Mains
Flexible Hose
Runouts Initially
Connected Together
4. Trisodium phosphate was formerly recommended
asacleaningagentduringushing.However,
many states and localities ban the introduction of
phosphates into their sewage systems. The current
recommendation
istosimplyushlongerwithwarm
80°F (27°C) water.
5.
Rellthesystemwithcleanwater.Testthewater
using litmus paper for acidity, and treat as required
to leave the water slightly alkaline (pH 7.5 to 8.5).
The
speciedpercentageofantifreezemayalsobe
added at this time. Use commercial grade antifreeze
designed for HVAC systems only. Do not use
automotive grade antifreeze.

Oncethesystemhasbeenlledwithcleanwater
and antifreeze (if used), precautions should be taken
to protect the system from dirty water conditions.
Dirty water will result in system wide degradation of
performance and solids may clog valves, strainers,
ow
regulators,etc.Additionally,theheatexchanger
may become clogged which reduces compressor
service life or causes premature failure.
6.
Set the loop water controller heat add setpoint
to 70°F (21°C) and the heat rejection setpoint to
85°F (29°C). Supply power to all motors and start
the
circulatingpumps.Afterfullowhasbeen
established through all components including the
heat rejector (regardless of season) and air vented
and loop temperatures stabilized, each of the
conditioners will be ready for check, test and start-
up, air balancing, and water balancing.
Start-up
1. Open all valves to full open position and turn on
power to the conditioner.
2.
Set thermostat for “Fan Only” operation by
selecting “Off” at the system switch and “On” at the
fan switch. If “Auto” fan operation is selected, the
fan will cycle with the compressor. Check for proper
air delivery.
3.
For those units that have two-speed motors,
reconnect for low speed operation if necessary.
4.
Set thermostat to “Cool.” If the thermostat is an
automatic changeover type, simply set the cooling
temperature to the coolest position. On manual
changeover types additionally select “Cool” at the
system switch.