LAARS EDN Series - Installation, Operation and Maintenance Instructions - Manual (Page 3)

Endurance Page 3
SECTION 1.
General Information
1.1 Introduction
EBP - This appliance is a low pressure, direct
vent, hot water boiler that provides priority domestic
hot water on demand as well as hydronic space
heating. The unit has a twenty gallon tank which holds
boiler water (as opposed to domestic water storage).
The boiler water is kept hot at all times to
provide immediate response to call for heat or
domestic water. Domestic water is heated by the boiler
water through a stainless steel plate heat exchanger.
EDP/EDN - This appliance is a low pressure,
direct vent, cold start hot water boiler that provides
heat for hydronic space heating. The model number
structure is shown in Figure 3.
Both appliances incorporate a circulating pump
and a bypass loop, and provide circulation for the
heating system and adequate flow for its own needs.
It may be necessary to install a system circulator to
achieve the required flow rate through the system.
Both appliances feature a forced draft, premixed
combustion system. All air for combustion is supplied
Figure 1. Combo Heating/Domestic Water (Model EBP).
with the gas to the burner (flame holder). Both the
intake air and the gas are metered through separate
orifices before entering the combustion air blower.
The blower forces the air/fuel mixture through the
flame holder and into the combustion chamber. The
mixture is ignited from the hot surface ignitor and
burns. Hot gases are forced out between the passes of
the heat exchanger into the flue collector. Flue gases
are discharged into the outside atmosphere through the
vent terminal.
The appliance can operate with a concentric vent
system that will provide outside air for combustion.
Other venting arrangements can be provided for the
appliance to include an alternative 50 equivalent feet
maximum horizontal or condensate trapped vertical
vent.
1.2 Codes and Standards
The Endurance may be a direct vent or Category
IV Boiler. All installations must be made in accordance
with:
a. The National Fuel Gas Code, ANSI Z223.1/
NFPA 54 latest edition, or
b. CSA B149.1 Natural Gas and Propane
Installation Code.
c. The requirements of the local utility or other
authorities having jurisdiction take precedence
over the general instructions contained herein.
All electrical wiring is to be done in accordance with:.
a. The National Electrical Code (NFPA 70), latest
edition or
Figure 2. Heating Unit (Model EDP/EDN).