18-GL07D1-4
15
2GN SPLIT INSTALLER’S GUIDE
Plumbing Installation
1. Inspect the dip tube in the water heater cold inlet
for a check valve. If a check valve is present it must
be removed or damage to the hot water generator
circulator will occur.
2. Remove drain valve and fi tting.
3. Thread the 3/4-inch NPT x 3-1/2-inch brass nipple into
the water heater drain port.
4. Attach the center port of the 3/4-inch FPT tee to the
opposite end of the brass nipple.
5. Attach the 1/2-inch copper to 3/4-inch NPT adaptor to
the side of the tee closest to the unit.
6. Install the drain valve on the tee opposite the adaptor.
7. Run interconnecting tubing from the tee to DHW water
out.
8. Cut the cold water “IN” line going to the water heater.
9. Insert the reducing solder tee in line with cold water
“IN” line as shown.
10. Run interconnecting copper tubing between the unit
DHW water “IN” and the tee (1/2-inch nominal). The
recommended maximum distance is 50 feet.
11. To prevent air entrapment in the system, install a vent
coupling at the highest point of the interconnecting
lines.
12. Insulate all exposed surfaces of both connecting water
lines with 3/8-inch wall closed cell insulation.
Note:
All plumbing and piping connections must comply with
local plumbing codes.
Hot Water Generator Startup
1. Close the drain valve to the water heater.
2. Open the cold water supply to the tank.
3. Open a hot water faucet in the building to bleed air
from the system. Close when full.
4. Open the pressure relief valve to bleed any remaining
air from the tank, then close.
5. If so equipped, unscrew the indicator plug 1 turn on
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.
6. Carefully inspect all plumbing for water leaks and
correct as required.
7. Before restoring electrical supply to the water heater,
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 specifi c 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.
8. After the thermostat(s) is adjusted, replace the access
cover and restore electrical supply to the water heater.
9. Make sure that any valves in the hot water generator
water circulating circuit are open.
10. Turn on the unit to fi rst stage heating.
11. The DHW pump should be running. When the pump
is fi rst started, open the inspection port 1 turn (if
equipped) until water dribbles out, then replace. Allow
the pump to run for at least fi ve minutes to ensure that
water has fi lled 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.
12. The temperature difference between the water entering
and leaving the hot water generator should be 5°F to
15°F. The water fl ow should be approximately 0.4 GPM
per ton of nominal cooling.
13. Allow the unit to heat water for 15 to 20 minutes to be
sure operation is normal.
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.
Summary of Contents for 2GN Series
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