Brochure

At A. O. Smith, we place the safety and
reliability of our products above all else. By
incorporating technologically advanced safety
features into every model, we provide the
assurance and peace of mind that can only
come from an A. O. Smith quality product.
Air-Fuel Ratio (AFR) Sensor
A. O. Smith’s unique AFR sensor monitors and
maintains proper combustion at all times.
Together with the onboard computer, this
system will adjust the fan motor speed to
ensure that air and fuel have a proper
mixture ratio, minimizing emissions and
maximizing efficiency.
Additional Safety Features
Freeze Protection:
Every heater in A. O. Smith’s tankless lineup
has an internal freeze protection system, which
is rated to protect the heaters when installed
in sub-freezing conditions. This system works
to keep water temperatures within the heat
exchanger from falling below a certain level,
preventing freeze damage.
SAFETY
HEAT EXCHANGER
IGNITER
AFR
FLAME SENSOR
BURNER
Hi-Limit Switch:
Ensures that water temperatures do not exceed safe levels. Before the water temperature can even reach these unsafe levels, the hi-limit
switch activates by disengaging the gas valves, effectively shutting down the water heater.
PVC Venting:
Indoor condensing models have a thermistor and hi-limit switch that monitor the exhaust temperature. If the exhaust temperature nears
an unsafe limit, these features regulate combustion and can shut the heater down to protect the integrity of the PVC vent material.
Overheat Cutoff Fuse:
Ensures that there are no breaches in the heat exchanger drum. In cases where enough physical damage might have been done to the
water heater to lead to a breach in the heat exchanger drum, the overheat cutoff fuse reacts by shutting down the water heater if
the surface of the heat exchanger retains too much heat.
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