14
NSZ/NDZ INSTALLATION MANUAL
Plumbing Installation
Inspect the dip tube in the water heater cold inlet
1.
for a check valve. If a check valve is present it must
be removed or damage to the hot water generator
circulator will occur.
Remove drain valve and fitting.
2.
Thread the 3/4-inch NPT x 3-1/2-inch brass nipple into
3.
the water heater drain port.
Attach the center port of the 3/4-inch FPT tee to the
4.
opposite end of the brass nipple.
Attach the 1/2-inch copper to 3/4-inch NPT adaptor to
5.
the side of the tee closest to the unit.
Install the drain valve on the tee opposite the adaptor.
6.
Run interconnecting tubing from the tee to DHW water
7.
out.
Cut the cold water “IN” line going to the water heater.
8.
Insert the reducing solder tee in line with cold water
9.
“IN” line as shown.
Run interconnecting copper tubing between the unit
10.
DHW water “IN” and the tee (1/2-inch nominal). The
recommended maximum distance is 50 feet.
To prevent air entrapment in the system, install a vent
11.
coupling at the highest point of the interconnecting
lines.
Insulate all exposed surfaces of both connecting water
12.
lines with 3/8-inch wall closed cell insulation.
NOTE:
All plumbing and piping connections must comply
with local plumbing codes.
CAUTION: Never operate the DHW circulating
pump while dry. If the unit is placed in operation
before the hot water generator piping is
connected, be sure that the pump switch is set
to the OFF position.
Hot Water Generator Connections cont.
Hot Water Generator Startup
Close the drain valve to the water heater.
1.
Open the cold water supply to the tank.
2.
Open a hot water faucet in the building to bleed air
3.
from the system. Close when full.
Open the pressure relief valve to bleed any remaining
4.
air from the tank, then close.
If so equipped, unscrew the indicator plug 1 turn on
5.
the motor end of the pump until all air is purged from
the pump, then tighten the plug. Use vent couplings to
bleed air from the lines.
Carefully inspect all plumbing for water leaks and
6.
correct as required.
Before restoring electrical supply to the water heater,
7.
adjust the temperature setting on the tank.
On tanks with both upper and lower elements,
•
the lower element should be turned down to
the lowest setting, approximately 100°F. The
upper element should be adjusted to 120°F to
130°F. Depending upon the specific needs of
the customer, you may want to adjust the upper
element differently.
On tanks with a single element, lower the
•
thermostat setting to 120°F.
After the thermostat(s) is adjusted, replace the access
8.
cover and restore electrical supply to the water heater.
Make sure that any valves in the hot water generator
9.
water circulating circuit are open.
Turn on the unit to first stage heating.
10.
The DHW pump should be running. When the pump
11.
is first started, open the inspection port 1 turn (if
equipped) until water dribbles out, then replace. Allow
the pump to run for at least five minutes to ensure that
water has filled the circulator properly. Be sure the
switch for the DHW pump (SW4) is “ON”. The DHW
“OFF” LED on the unit should not be illuminated.
The temperature difference between the water
12.
entering and leaving the hot water generator should be
5°F to 15°F. The water flow should be approximately
0.4 GPM per ton of nominal cooling.
Allow the unit to heat water for 15 to 20 minutes to be
13.
sure operation is normal.
