Install Instructions

Installation & Operation Manual
58
11 Operating information
General
How the water heater operates
The Armor wall mount water heater uses an advanced stainless
steel heat exchanger and electronic control module that allows
fully condensing operation. The blower pulls in air and pushes
flue products out of the water heater through the heat exchanger
and flue piping. The control module regulates blower speed to
control the water heater firing rate. The gas valve senses the
amount of air flowing into the water heater and allows only the
right amount of gas to flow.
Control inputs and outputs
Tank thermostat / tank sensor
Either of these inputs will tell the water heater to provide heat
to the water tank. If a tank sensor is connected, the SMART
SYSTEM control will ignore the tank thermostat.
0 - 10VDC input (set point or power)
The Armor wall mount water heater can be controlled by a
Building Management System (BMS) using a 0 - 10 VDC signal.
The control can be configured by the installer to use this signal
to either control set point or firing rate. This signal can be sent
to the heater through ModBus as well.
Temperature control
Modulation
The Armor wall mount water heater is capable of modulating
its firing rate from a minimum of 20% to a maximum of 100%.
The firing rate is dictated by the hot water draw and various
other temperature limitations.
Night setback
The controller may be programmed to reduce the DHW set
point during certain times each week. Seven different start and
stop times per week may be programmed for the DHW setback.
Flame current support
To prevent nuisance shutdowns when the water heater is firing
at minimum rates, the control will increase fan speed when the
flame signal drops too low.
Protection features
Outlet temperature, flue temperature, and temperature
rise limiting
The outlet temperature is monitored by the water heater outlet
temperature sensor. When the outlet temperature exceeds
185°F, the unit will reduce the fan speed. If the outlet water
temperature exceeds 195°F the control will shut the unit down
until it cools off.
The control module monitors the flue temperature by a sensor
located in the flue exhaust. If the flue temperature exceeds
215°F the control will reduce the maximum fan speed. If the
flue temperature exceeds 225°F (107°C) the control will shut
the unit down. The unit will restart automatically once the flue
temperature drops 10°F (6°C) and the minimum off time has
expired.
The control monitors the temperature difference between
the inlet and the outlet sensor. If the control determines the
temperature rise is too high, it will either reduce the firing rate
or shut down the unit as appropriate.
The unit will restart automatically once the temperature
difference has dropped below the allowable rise and the
minimum off time has expired.
Freeze protection
DO NOT install the water heater in a room likely to freeze.
The following integral feature of the SMART SYSTEM control
module provides some protection for the water heater.
• The SMART SYSTEM control module provides
freeze-up protection as follows when the water heater
water temperature drops below 45°F:
• Below 45°F, the water heater pump operates constantly.
• Below 37°F, the water heater turns on.
• The water heater and pump will turn off if water
heater water temperature rises above 45°F.
This feature of the SMART SYSTEM control
module does not eliminate the possibility
of freezing. The installation must still
use recognized design, installation and
maintenance practice to prevent freeze
potential for the water heater.
⚠ CAUTION