6
IMPROPER AND INEFFICIENT OPERATION OF THE APPLIANCE
RESULTING IN THE PRODUCTION OF INCREASED LEVELS
OF CARBON MONOXIDE GAS IN EXCESS OF SAFE LIMITS
WHICH COULD RESULT IN SERIOUS PERSONAL INJURY OR
DEATH.
You should contact your gas supplier for any specific changes
which may be required in your area.
As elevation above sea level is increased, there is less oxygen
per cubic foot of air. Therefore, the heater input rate should be
reduced at high altitudes for satisfactory operation with the
reduced oxygen supply. Failure to make this reduction would
result in an overfiring of the heater causing sooting, poor
combustion and/or unsatisfactory heater performance.

U.S. REQUIREMENTS

Ratings specified by manufacturers for most appliances apply
for elevations up to 2000 feet (610m). For elevations above
2000 feet (610), ratings must be reduced at the rate of 4% for
each 1000 feet (305m) above sea level. For example, if a heater
is rated at 120,000 Btuh (35 kWh) at sea level, to rate the heater
at 4000 feet (1219m), you subtract 4 (once for each thousand
feet) x .04 (4% input reduction) x 120,000 (original rating) from
the original rating. Therefore, to calculate the input rating at
4,000 feet (121.9m): 4 x .04 x 120,000 =19,200 Btuh (5.6 kWh),
120,000 (35 kWh) - 19,200 (5.6 kWh) = 100,800 Btuh (29.4 kWh).
At 6000 feet (1829m) the correct input rating should be 91,200
Btuh (26.7 kWh).

CANADIAN REQUIREMENTS

Appliances with inputs up to and including 400,000 BTU (117.2
kW) must be factory equipped with orifices for operation at
specific elevations. Standard (sea level) orifices permit
operation up to 2000' (610m) elevation. For operation between
2000' (610m) and 4500' (1370m) specify "HIGH ALTITUDE
OPERATION" when ordering the heater(s). For operation above
4500' (2370m) consult factory before ordering.

Field conversion for operation at altitudes other than

that specified on the heater rating plate is not

permitted.

The input reduction is primarily achieved by reducing the size of
the main burner orifices. To do this, the main burner orifices
require replacement with orifices sized for the particular
installation elevation. Correct orifice sizing and parts may be
obtained from State Water Heaters. When ordering, be sure to
state the model number and the altitude of the location where
the water heater is being installed.
Upon completion of derating of the heater, adjustment to the gas
pressure regulator may be required. See CHECKING THE
INPUT section in this manual for inlet and manifold pressure
requirements.
Also due to the input rating reduction required at high altitudes,
the output rating of the appliance is reduced and should be
compensated for in the sizing of the equipment for application.
FEATURES

SELF-CLEANING HYDRO CANNON

These units include a self-cleaning hydro cannon installed in
the front water inlet. See figure 2. The hydro cannon must be
oriented correctly for proper function. There is a marked range
on the pipe nipple portion of the hydro cannon, that must be
aligned with the top of the inlet spud. A label above the jacket
hole has an arrow that will point to the marked portion of the pipe
nipple if the orientation is correct. If the arrow does not point
within the marked range on the pipe nipple, adjust the pipe
nipple to correct. A pipe union is supplied with the hydro cannon
to reduce the probability of misaligning the hydro cannon
accidentally while tightening the connection to the inlet water
supply line. Improper orientation of the hydro-canon can cause
poor performance of the heater and can significantly reduce
outlet water temperatures during heavy draws.
NOTE: The inlet tube may have 1, 3 or 7 cross-tubes.
FIGURE 2
For proper function, the hydro cannon must be oriented correctly.
There is a marked range on the pipe nipple that must be aligned
with the top of the inlet spud (check for label on the appliance) to
assure proper orientation. Please check to confirm that the
marked range is in alignment with the top of the spud. A pipe
union is supplied with the hydro cannon to help eliminate the
possibility of changing the orientation by accidentally over-
tightening the inlet supply line. Improper orientation of the
hydro cannon may cause temperature build-up issues or spells
of colder than usual water temperatures.

HIGH LIMIT SWITCH (E.C.O.)

The dual bulb controller (fig. 3) contains the high limit (energy
cutoff) sensor. The high limit switch interrupts main burner gas
flow should the water temperature reach 205°F (96°C).
In the event of high limit switch operation, the appliance cannot
be restarted unless the water temperature is reduced by at least
20°F (11°C) and the high limit reset button on front of limit control
(fig. 3) is depressed.
Continued manual resetting of high limit control, preceded by
higher than usual water temperature is evidence of high limit
switch operation. The following is a possible reason for high
limit switch operation.
• A malfunction in the thermostatic controls would allow the
gas valve to remain open causing water temperature to exceed
the thermostat setting. The water temperature would continue
to rise until high limit switch operation.
Contact your dealer or servicer if continued high limit switch
operation occurs.
DUAL-BULB THERMOSTAT (COVER REMOVED)
FIGURE 3