35
Installation & Operation Manual
4
Water connections
Figure 4-1_Water Connections - Models 400 - 750
CAUTION
An appliance allowed to operate at return
temperatures below the specified minimum
setting may experience problems with
the operating controls, safety switches,
obstruction of the flue gas passages on the
heat exchanger, incomplete combustion
and possible flue gas spillage. Sustained
operation at lower than specified water
temperatures (140°F) may cause hazardous
conditions that may result in personal injury
or non-warrantable damage to the appliance.
Inlet and outlet connections
For ease of service, install unions on the water inlet and
water outlet of the unit. The connection to the unit marked
“Inlet” on the header should be used for return from the
system. The connection on the header marked “Outlet” is
to be connected to the supply side of the system.
IMG00591
2" NPT
WATER
OUTLET
2" NPT
WATER
INLET
INSPECTION
PLUGS
Water flow switch
A water flow switch is factory installed in the outlet on all water
heaters. The flow switch must prove water flow before a trial for
ignition can begin. The flow switch requires a minimum flow
of 15 - 18 GPM on Models 400 - 750 and 26 GPM on Models
1000 - 2100 to make the flow switch and start burner operation.
A water flow switch meets most code requirements for a low
water cutoff device on water heaters requiring forced circulation
for operation.
Low water cutoff
(if equipped)
If this unit is installed above radiation level, a low water cutoff
device must be installed at the time of water heater installation.
An electronic low water cutoff is available as a factory supplied
option on all models. The low water cutoff should be inspected
every 6 months.
Relief valve
This unit is supplied with a safety relief valve(s) sized in
accordance with ASME Boiler and Pressure Vessel Code,
Section IV (“Rules for Construction of Heating Boilers”). The
relief valve(s) is installed in the vertical position and mounted in
the hot water outlet. No valve is to be placed between the relief
valve and the unit. To prevent water damage, the discharge
from the relief valve shall be piped to a suitable floor drain for
disposal when relief occurs. No reducing couplings or other
restrictions shall be installed in the discharge line. The discharge
line shall allow complete drainage of the valve and line. Relief
valves should be manually operated at least once a year.
CAUTION
Avoid contact with hot discharge water.
Figure 4-2_Water Connections - Models 1000 - 2100
IMG00592
2-1/2" NPT
WATER
OUTLET
2-1/2" NPT
WATER
INLET
INSPECTION
PLUGS
Initial set-up of maximum water flow
On initial start-up of the Genesis, the maximum water flow to
the heat exchanger must be checked and manually limited with
a valve or bypass before normal operation begins.
