Features and components, The eliminator (self-cleaning system), High limit switch – State SBN85 390NE A User Manual

Page 7: Electronic ignition control, Exhaust inducer (blower assy.), Uncrating, Low gas pressure switch

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the eliminator (self-Cleaning system)

These units include The eliminator (Self-Cleaning System)

installed in the front water inlet, See Figure 1. The eliminator inlet

tube can only be used in the front water inlet connection. Do not

install the eliminator inlet tube in either the top or back inlet water

connection. The eliminator must be oriented correctly for proper

function. There is a marked range on the pipe nipple portion of

the eliminator, 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 eliminator to reduce the probability of misaligning the

eliminator accidentally while tightening the connection to the inlet

water supply line. Improper orientation of the eliminator can cause

poor performance of the heater and can significantly reduce outlet

water temperatures during heavy draws.

note: the eliminator may have 1, 3 or 7 cross tubes.

figure 1.

high limit switCh

The digital thermostat (Figure 2) contains the high limit (energy

cutoff) switch. The high limit switch interrupts main burner gas

flow should the water temperature reach 203°F (95°C).
In the event of high limit switch operation, the appliance cannot

be restarted unless the water temperature is reduced to

approximately 120°F (49°C). The high limit reset button on the

front of the control then needs to be 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 qualified service agency if continued high

limit switch operation occurs.

digital thermostat

figure 2.

eleCtroniC ignition Control

each heater is equipped with a ignition module. The solid state

ignition control (Figure 3), ignites the main burner by utilizing a

silicon nitride igniter. The silicon nitride igniter shuts off during

the heating cycle and the main burner flame is sensed through

a remote flame sensor integral to the silicon nitride igniter

assembly.
The ignition control will try to ignite the main burner three times

before lockout. Then it waits one hour before trying again to ignite

the main burners. This is a continuous cycle.

ignition Control Board

figure 3.

exhaust induCer (Blower assy.)

All models are equipped with an exhaust inducer. The inducer

assists in drawing in fresh air to the unit for combustion and then

assists in dispensing the combustion by-products into the venting

leading outside.
The exhaust inducer is equipped with a gravity controlled damper

to reduce the amount of heat loss through the flue, improving

efficiency.

exhaust induCer

figure 4.

unCrating

The heater is shipped with the inducer already installed. The

wiring conduit runs from the thermostat to the inducer. Before

turning unit on, check to make sure the wiring conduit is securely

plugged into the inducer.

low gas pressure switCh

The low Gas Pressure Switch monitors the gas supply pressure.

If the gas supply pressure drops below 5.2” W.C., the burners are

extinguished (if the heater is running) or the heater will not start up.

features and Components

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