Installation manual

11
PREMIER INSTALLATION MANUAL
System Cleaning and Flushing
Prior to start up of any heat pump, the water circulating system must be cleaned and fl ushed of all dirt and debris. If
the system is equipped with water shutoff valves, the supply and return runouts must be connected together at each unit
location to prevent the introduction of dirt into the unit, (see Figure 10). The system should be fi lled at the water makeup
connection with all air vents open. After fi lling, vents should be closed.
The contractor should start the main circulator with the pressure reducing valve makeup open. Vents should be checked
in sequence to bleed off any trapped air and to verify circulation through all components of the system.
As water cirulates through the system, the contractor should check and repair any leaks found in the piping system.
Drain(s) at the lowest point(s) in the system should be opened for the initial fl ush and blowdown, making sure water fi ll
valves are set at the same rate. Check the pressure gauge at the pump suction and manually adjust the makeup water
valve to hold the same positive pressure both before and after opening the drain valves. Flushing should continue for at
least two hours, or longer if required, unil drain water is clean and clear.
The supplemental heater and/or circulator pump, if used, should be shut off. All drains and vents should be opened to
completely drain the system. Short circuited supply and return runouts should now be connected to the unit supply and
return connections.
Refi ll the system with clean water. Test the system water for acidity and treat as required to leave the water slightly
alkaline (pH 7.5 to 8.5). The specifi ed percentage of antifreeze may also be added at this time. Use commercial grade
antifreeze designed for HVAC systems only. Environol™ brand antifreeze is recommended.
Once the system has been fi 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, fl ow regulators, etc. Additionally, the heat exchanger may become clogged which reduces compressor
service life and can cause premature unit failure. In boiler/tower applications, set the loop control panel set points to desired
temperatures. Supply power to all motors and start the circulating pumps. After full fl ow has been established through all
components including the heat rejector (regardless of season), air vented and loop temperatures stabilized, each of the
units will be ready for check, test and start up and for air and water balancing.
Note: For closed loop systems with antifreeze protection, set SW2-2 to the “LOOP” position.
Return Runout
Supply Runout
Mains
Rubber Hose
Runouts initially
connected together
Figure 10: Flushing with Water Shutoff Valve Equipped Systems