LAARS U.H.E. - Service Manual - Manual (Page 3)

U.H.E Service Manual Page 3
Introduction
The LAARS heating system Ultra High Efficiency Water Heater uses a low Nox
premix power burner located at the top of the water heater to direct a turbulent
flame down into a submerged combustion chamber. This turbulence causes a
thorough mixing of gas and air for optimum combustion. The combustion gases
then travel through a three pass flue system keeping the gases moving at a high
velocity. The combination of high turbulence and velocity results in an optimum
transfer of heat from the flue gases into the water.
Burner operation is controlled using an electronic ignition module. The module
monitors the status of the electronic thermostat, vent temperature limit switch, vent
system pressure switches and a flame sensor to control output voltage to blower
motor, hot surface igniter and gas valve. The module contains programming which
determines the sequence of operation and timings for purge periods, trial for
ignition, flame sensing and lockout. The module will also provide diagnostic
information to help in determining the cause of system lockouts.
The contents in this manual are detailed informational tools to assist in the proper
diagnosis of the Ultra High Efficiency Water Heater operational faults. Please read
this service manual completely and provide as much information regarding the
Ultra High Efficiency Water Heater operation and installation specific concerns.
The LAARS heating system Ultra High Efficiency Water Heater is designed to
deliver a remarkable thermal efficiency rating in a quiet running unit with venting
options that allow for installation flexibility. Several technologically advanced
design features are incorporated in the design that will require additional
knowledge on the part of the qualified service provider. The information in this
manual will instruct service and maintenance professionals on the function, proper
diagnosis and repair of LAARS Heating System Ultra High Efficiency Water
Heater.
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U.H.E. Series Commercial Gas
Ultra High Efficiency Water Heaters